JPH0925315A - Acetoacetic ester group-containing polyvinyl alcohol resin composition and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an acetoacetic ester group-containing polyvinyl alcohol resin composition having discoloration resistance and good stability of aqueous solution by using a specified acetoacetic ester group-containing polyvinyl alcohol resin composition as the composition. SOLUTION: This acetoacetic ester group-containing polyvinyl alcohol resin composition containins 8wt.% or below methyl acetoacetate. An emulsion stabilizer based on this composition is desirable.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel composition of a polyvinyl alcohol resin containing an acetoacetic acid ester group (hereinafter abbreviated as AA-PVA) and its use.

[0002]

2. Description of the Related Art Conventionally, a polyvinyl alcohol resin (hereinafter abbreviated as PVA) has been used as an emulsion dispersion stabilizer by utilizing its film forming performance (film forming property, oil resistance, strength, etc.) and water solubility.
Widely used as paper processing agents, adhesives, suspension agents, surfactants, fiber processing agents, etc.

Modification of PVA has been attempted according to its various uses and required performances. One of them is
AA-PVA containing an acetoacetic acid ester group (hereinafter abbreviated as AA group) is known.

The aqueous solution of the AA-PVA is used as an emulsion dispersion stabilizer, a paper processing agent, an adhesive, a suspending agent, a surfactant, a fiber processing agent, etc. as described above.

[0005]

However, there is a general belief that the AA-PVA is a resin that is more easily colored than conventional PVA, and there has been no attempt to improve this coloring much positively. The current situation. However, in recent years, AA-PVA has been used in a large amount in a wide range of applications due to its excellent properties, and improvement in coloring has also been required. Furthermore, the AA-ized P
In each application using VA, with the advancement of technology, higher quality physical properties, which had hardly been a problem in the past, are required, and for example, the aqueous solution used in the various applications described above is required. Further stability and stability of emulsion liquid produced when used for emulsion dispersion stabilizer applications, paper processing agents,
Especially when used as an overcoating agent for thermal recording paper,
It was found that there is still room for improvement, including the adhesiveness when used as an adhesive.

[0006]

[Means for Solving the Problems] The inventors of the present invention have diligently studied to overcome such a problem, and as a result of repeated studies focusing on methyl acetoacetate contained in AA-PVA, as a result, AA-PVA composition containing less than or equal to wt.
Little coloring, excellent stability of its aqueous solution, stability and non-coloring property of emulsion produced when used as an emulsion dispersion stabilizer, paper processing agent, especially when used as an overcoat agent for thermal recording paper. It was found that the performance, and further the adhesiveness when used in an adhesive, was extremely excellent, and the present invention was completed.

The AA-PVA composition used in the present invention will be described in detail below. The AA-PVA of the present invention is PV
It may be produced by any method such as a method of reacting A with diketene, a method of reacting PVA with acetoacetic acid ester for transesterification, or a method of copolymerizing vinyl acetate and vinyl acetoacetate, but the production process is simple. , Good quality A
From the viewpoint that A-PVA can be obtained, it is preferably produced by a method of reacting PVA and diketene. As a method of reacting PVA powder and diketene, PVA may be directly reacted with gaseous or liquid diketene, or after PVA powder is adsorbed and occluded with an organic acid in advance, it is liquid or gas under an inert gas atmosphere. Spray diketene, react or
Alternatively, a method of spraying and reacting a mixture of an organic acid and liquid diketene on PVA powder is used.

In the method using an organic acid, acetic acid is most advantageous as the organic acid, but the organic acid is not limited to this, and propionic acid, butyric acid, isobutyric acid and the like may be optionally used. The amount of the organic acid is preferably an amount within the limit that the PVA powder in the reaction system can adsorb and occlude, in other words, an amount such that the organic acid separated from the resin in the reaction system does not exist. Specifically, 0.1 to 80 parts by weight, preferably 0.5 to 50 parts by weight, and particularly preferably 5 to 100 parts by weight of PVA.
It is suitable to coexist with 30 parts by weight of an organic acid. 0.
If it is less than 1 part by weight, the effect of the present invention is difficult to obtain, while if it exceeds 80 parts by weight and an excess of organic acid is present, a product having a non-uniform degree of acetoacetate esterification (hereinafter abbreviated as AA degree) is easily obtained. , Unreacted diketene tends to increase.

In order to uniformly adsorb and store the organic acid in the PVA, any means such as a method of spraying the organic acid alone on the PVA, a method of dissolving the organic acid in an appropriate solvent and spraying it can be implemented. is there.

The reaction conditions for PVA and diketene include:
When the liquid diketene is uniformly adsorbed on and absorbed by the PVA powder by means such as spraying, it is preferable to heat to a temperature of 20 to 120 ° C. in an inert gas atmosphere and continue stirring or fluidization for a predetermined time.

When the diketene gas is reacted, the contact temperature is 0 to 200 ° C., preferably 25 to 100 ° C., and the contact is carried out under the temperature at which the gaseous diketene does not liquefy upon contact with PVA and the diketene partial pressure condition. Although it is preferable that a part of the gas becomes droplets, there is no problem. The contact time depends on the contact temperature, that is, when the temperature is low, the time may be long, and when the temperature is high, the time may be short, and is appropriately selected from the range of 1 minute to 6 hours.

When the diketene gas is supplied, the diketene gas as it is or a mixed gas of the diketene gas and an inert gas may be used. The powder PVA may absorb the gas and then raise the temperature, but the powder is heated. However, it is preferable to contact the gas after heating.

Basic compounds such as sodium acetate, potassium acetate, primary amines, secondary amines and tertiary amines are effective as catalysts for the reaction of acetoacetic acid esterification (hereinafter abbreviated as AA). The amount of the catalyst may be smaller than that in the known reaction method, and is 0.1 to 1.0% by weight based on the PVA powder. Since PVA powder usually contains sodium acetate, it is often unnecessary to add a catalyst. When the amount of the catalyst is too large, a side reaction of diketene is likely to occur, which is not preferable. As a reaction device for carrying out AA, a device capable of heating and equipped with a stirrer is sufficient. For example, a kneader, a Henschel mixer, a ribbon blender, other various blenders, and a stirring and drying device.

PV as a starting material for such AA-PVA
A is PV obtained by saponifying a lower alcohol solution of polyvinyl acetate with a saponification catalyst such as alkali.
A, a derivative thereof, and a saponified product of a copolymer of vinyl acetate and a monomer having copolymerizability with vinyl acetate,
A is not particularly limited, but the average degree of saponification is 30 to 99.0.
The average degree of polymerization is preferably 80 to 99.9 mol% and the average degree of polymerization is 200 to 3,000.

Examples of the monomer include ethylene, propylene, isobutylene, α-octene, α-dodecene,
Olefins such as α-octadecene, acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride,
Unsaturated acids such as itaconic acid or salts thereof or mono- or dialkyl esters, nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide and methacrylamide, olefins such as ethylenesulfonic acid, allylsulfonic acid and methallylsulfonic acid Sulfonic acid or its salt, alkyl vinyl ethers,
N-acrylamidomethyltrimethylammonium chloride, allyltrimethylammonium chloride, dimethyldiallylammonium chloride, dimethylallyl vinyl ketone, N-vinylpyrrolidone, vinyl chloride, vinylidene chloride, polyoxyethylene (meth) allyl ether, polyoxypropylene (meth) allyl Polyoxyalkylene (meth) allyl ether such as ether, polyoxyethylene (meth) acrylate, polyoxyalkylene (meth) acrylate such as polyoxypropylene (meth) acrylate, polyoxyethylene (meth)
Acrylamide, polyoxyalkylene (meth) acrylamide such as polyoxypropylene (meth) acrylamide, polyoxyethylene (1- (meth) acrylamide-1,1-dimethylpropyl) ester, polyoxyethylene vinyl ether, polyoxypropylene vinyl ether, poly Examples thereof include saponified copolymers with oxyethylene allylamine, polyoxypropylene allylamine, polyoxyethylene vinyl amine, polyoxypropylene vinyl amine and the like.

PVA is preferably in the form of powder, in particular, has a narrow particle size distribution and is porous because it contributes to uniform adsorption of diketene, uniform reaction by absorption, and improvement of reaction rate of diketene. The particle size is 50 to 450 mesh, preferably 80 to 320 mesh.

Some PVA products contain several percent of alcohols, esters and water during the manufacturing process,
These components react with diketene, consume diketene, and reduce the reaction rate of diketene.Therefore, when using for reaction, after heating or reducing the pressure, it should be reduced as much as possible. It is desirable to use.

The degree of AA conversion of the AA-modified PVA thus obtained is in the range of 0.01 to 20 mol%, more preferably 1 to 15 mol%. Effect is not exhibited, there is not much difference from ordinary PVA, and if it exceeds 20 mol%, the solubility and stability in water are poor, which is not preferable.

The greatest feature of the present invention is that the AA-PVA contains a specific amount of methyl acetoacetate.

In the present invention, methyl acetoacetate must be contained in an amount of 8% by weight or less, preferably 5% by weight or less, more preferably 3% by weight or less. When the methyl acetoacetate content exceeds 8% by weight, the AA-PVA composition is markedly colored, and when the composition is used as an aqueous solution, the viscosity stability is poor and when it is used as an emulsion dispersion stabilizer. It is not preferable because the tendency of thickening becomes strong and coloring is caused, and various properties when used as a paper processing agent, particularly an overcoat agent for heat-sensitive recording paper and adhesiveness when used as an adhesive are deteriorated. As a method for quantifying methyl acetoacetate in the present invention, gas chromatography / mass spectrometry (GC / MS method) is used.

The control of the content of methyl acetoacetate is essential as long as the final product falls within the scope of the present invention, and the control is arbitrary. For example, AA
Controlling the amount of methyl acetoacetate used when producing modified PVA by transesterification, and controlling the amount of acetic acid and methanol and the number of washings when removing methyl acetoacetate by washing with acetic acid and methanol after the reaction. The drying conditions for distilling off methyl acetoacetate may be controlled, and when AA-modified PVA is produced by PVA and diketene, methyl acetoacetate produced from unreacted diketene and methanol is treated with methanol as described above. Alternatively, it may be controlled by washing with acetic acid or drying. Further, either addition of methyl acetoacetate to the raw material used for the production of AA-PVA or addition of methyl acetoacetate after the production of AA-PVA is optional. When methyl acetoacetate is added, methyl acetoacetate may be added as it is in a liquid state or in a gas state, added with an alcohol such as methanol, ethanol, isopropanol, or added with acetic acid.

In order to remove methyl acetoacetate, the AA-PVA is treated by a method such as distillation under reduced pressure, washing with methanol, drying treatment, filtration and centrifugation alone or in combination. As a treatment method, preferably, after washing with methanol, it is filtered and dried. In this case, as the methanol washing, it is preferable to wash twice with 0.1 to 15 times the weight of AA-PVA and further filter and then dry. The drying treatment conditions vary depending on the device, but are 30 to 80 ° C. -10
It may be carried out for about an hour, and preferably 40 to 70 ° C. and 3 to
Do about 6 hours.

The AA-PVA composition of the present invention has good aqueous solution stability and can be used in various applications. However, when it is used as an emulsion dispersion stabilizer, the stability and non-coloring property of the produced emulsion are improved. It is particularly useful for such applications because it has excellent performances such as fog, color density, and sticking when used as an overcoating agent for heat-sensitive recording paper, adhesive strength when used as an adhesive, water resistance, and initial adhesive strength.

Next, the emulsion polymerization method for unsaturated monomers using the AA-PVA composition of the present invention as an emulsion dispersion stabilizer will be specifically described. When emulsion polymerization is carried out, an ordinary emulsion polymerization method such as adding an unsaturated monomer temporarily or continuously in the presence of water, an emulsion dispersion stabilizer and a polymerization catalyst, heating and stirring is carried out. Can be done. AA-PV of the present invention
The composition A is added to the aqueous medium as a powder or as an aqueous solution. The amount used is somewhat different depending on the amount of modification of the AA-PVA composition of the present invention, the required resin content of the emulsion, etc., but is usually 1 to 50% by weight based on the unsaturated monomer,
It is preferably selected from the range of about 2 to 20% by weight.

The catalyst used is preferably a water-soluble catalyst, especially a radical generator. For example, potassium persulfate, ammonium persulfate, etc. may be used alone or in combination with acidic sodium sulfite, and further hydrogen peroxide-tartaric acid may be used. , Hydrogen peroxide-iron salt, hydrogen peroxide-ascorbic acid-iron salt, hydrogen peroxide-Rongalit, hydrogen peroxide-Rongalit-iron salt, etc. are used.
Further, although it is possible to obtain the effects of the present invention sufficiently by using the AA-PVA composition alone, various surfactants (for example, anionic surfactants such as dodecylbenzenesulfonic acid and fatty acid salts, etc. Nonionic surfactants) or emulsifiers (eg, cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, polyacrylic acid derivatives, (anhydrous) maleic acid-vinyl ether copolymers, (anhydrous) maleic acid-
Vinyl acetate copolymers, vinyl acetate- (meth) allyl sulfonic acid (salt) copolymer saponification products, etc.), and various PVA and PVA derivatives known as protective colloids can also be appropriately used in combination. Further, a plasticizer such as phthalic acid ester or phosphoric acid ester, a pH adjusting agent such as sodium carbonate, sodium acetate, sodium phosphate, or the like may be used in combination.

The unsaturated monomers to be emulsion-polymerized include ethylenically unsaturated monomers and butadiene monomers, and the ethylenically unsaturated monomers include vinyl acetate and acrylic acid. Esters, methacrylic acid esters, vinyl chloride, vinylidene chloride, acrylonitrile, styrene and the like can be mentioned, and homopolymerization or copolymerization thereof can be carried out. In particular, when homopolymerizing or copolymerizing acrylic monomers such as acrylic acid ester and methacrylic acid ester, a remarkable effect that an emulsion having particularly good mechanical stability, storage stability, pigment miscibility, etc. can be obtained. Therefore, emulsion polymerization of acrylic monomers is preferably carried out.

As the butadiene-based monomer, there are butadiene, 2-methylbutadiene, 2,3-dimethylbutadiene, 2-chlorobutadiene and the like, which are used alone or mixed with an ethylenically unsaturated monomer. To be Among these, butadiene and styrene, butadiene and styrene and (meth) acrylic acid, butadiene and acrylonitrile,
It is advantageous to carry out the polymerization with a combination of butadiene, acrylonitrile and styrene, butadiene and acrylonitrile and (meth) acrylic acid, butadiene and methyl methacrylate, butadiene and methyl methacrylate and (meth) acrylic acid.

The emulsion polymerization using the AA-PVA composition of the present invention as an emulsion dispersion stabilizer and the emulsion obtained by such polymerization have been described above.
The emulsion dispersion stabilizer using the modified PVA composition is useful even when an emulsion is produced by the post-emulsification method. In this case, the dispersion stabilizer is dissolved in water and the solution or molten resin is dissolved in the dispersion stabilizer. May be added dropwise and stirred. No special measures such as heating are required for emulsification, but heating may be performed at about 45 to 85 ° C., if necessary.
The substance to be emulsified is not particularly limited, epoxy resin, urethane resin, urea-formaldehyde precondensate, phenol-formaldehyde precondensate, alkyd resin,
Ketene dimer, rosin, silicone resin, wax,
Examples include polyolefin resins and asphalt.
If necessary, nonionic activators or emulsifiers such as polyoxyethylene-alkyl ether type, polyoxyethylene-alkylphenol type, polyhydric alcohol ester type, various PVA and PVA derivatives known as protective colloids, or higher alcohol sulfuric acid. Various surfactants used at the time of emulsion polymerization can be used, including anionic surfactants such as salts. Further, these surfactants can be mixed in the object to be emulsified, and, as described above, plasticizers such as phthalic acid ester and phosphoric acid ester, sodium carbonate, sodium acetate, phosphoric acid, etc. A pH adjusting agent such as sodium can also be used in combination.

Although the application as an emulsion dispersion stabilizer has been described above, the AA-PVA composition of the present invention is also useful as a paper processing agent, and the application will be specifically described.

Among the applications as a paper finishing agent containing the AA-PVA composition of the present invention, as a coating liquid for overcoating on a thermosensitive color-forming layer composed of a color-forming substance, a developer and a binder. Useful, which will be described in detail below.

First, in the preparation of a coating liquid for forming a thermosensitive coloring layer, an aqueous dispersion of a color-forming substance and an aqueous dispersion of a color developer are separately prepared, and they are sufficiently stirred to be slightly stirred. After pulverization, a uniform dispersion type coating liquid can be obtained simply by mixing and stirring both liquids. The binder component is added to at least one of the aqueous dispersion of the coloring substance and the aqueous dispersion of the color developer. The binder component is suitably 10 to 200% by weight with respect to the total amount of the color forming substance and the color developing agent. The solid content concentration of the coating liquid is 10 to 10 in consideration of workability.
It is selected from the range of 40% by weight. As the binder, for example, PVA, modified PVA such as PVA containing a carboxyl group,
Methylcellulose, carboxymethylcellulose, starches, latices or the same resin as the protective layer of the present invention can be used.

Examples of the color-forming substance are 3,3-bis (P-dimethylaminophenyl) -phthalide and 3,3-bis.
Bis (P-dimethylaminophenyl) -6-dimethylaminophthalide [crystal violet lactone],
3,3-bis (P-dimethylaminophenyl) -6-
Diethylaminophthalide, 3,3-bis (P-dimethylaminophenyl) -6-chlorophthalide, 3-dimethylamino-6-methoxyfluorane, 7-acetamino-
3-diethylaminofluorane, 3-diethylamino-
5,7-Dimethylfluorane, 3-diethylamino-
Examples thereof include leuco compounds of triphenylmethane dyes such as 5,7-dimethylfluorane, 3,6-bis-β-methoxyethoxyfluorane, and 3,6-bis-β-cyanoethoxyfluorane.

The color developer is one which reacts with the above-mentioned color-forming substance upon heating and reacts, and which liquefies or vaporizes at room temperature or higher, preferably 70 ° C. or higher, such as phenol or P.
-Methylphenol, P-tert-butylphenol, P-phenylphenol, α-naphthol, β-naphthol, 4,4'-isopropylidenediphenol [bisphenol A], 4,4'-secondary butylidene diphenol, 4, 4'-cyclohexylidene diphenol, 4,4'-isopropylidene bis (2-tert-butylphenol), 4,4 '-(1-methyl-n-hexylidene) diphenol, 4,4'-isopropylidene Dendicatechol, 4,4'-pentylidene diphenol,
4,4-isopropylidene bis (2-chlorophenol), phenyl-4-hydroxybenzoate, salicylic acid, 3-phenylsalicylic acid, 5-methylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 1-
Examples thereof include oxy-2-naphthoic acid, m-oxybenzoic acid, 4-oxyphthalic acid and gallic acid, but the color-forming substance and the color developer are not limited to these.

For coating, any known method such as a roll coater method, an air-coating method, a blade coater method or the like may be employed. Therefore, the coating amount of the coating liquid is 1 to 20 g / m ^2, especially 3 to 10 g / m ^2.
It is appropriate to set it to a degree. The heat-sensitive recording layer thus obtained is coated with a paper processing agent using the AA-PVA composition of the present invention as a protective film.

The paper processing agent is an aqueous solution comprising the AA-PVA composition of the present invention and a pigment, and the pigment is silicic acid anhydride.
(Colloidal silica), kaolinite clay, calcined kaolinite clay, pyrophyllite, hydrous halloysite,
Sericite clay, sericite, talc, titanium oxide, calcium carbonate, aluminum silicate, calcium silicate,
Aluminum hydroxide etc. are mentioned. As a method for allowing the pigment to coexist, the AA-PVA composition of the present invention is mixed with the pigment, the pigment is allowed to coexist during the production of the raw material PVA of the AA-PVA composition of the present invention, or the PVA is reacted with diketene. A pigment may be coexistent at the time of AA conversion.

The amount of the pigment used is 5 to 300 parts by weight, preferably 5 parts by weight per 100 parts by weight of the AA-PVA composition of the present invention.
If it is less than 5 parts by weight, sticking may occur, while if it exceeds 300 parts by weight, the color density of printing and the resistance to plasticizer may be markedly deteriorated, leaving a problem in practical use.

Any auxiliary operation such as mixing various known auxiliary agents or coating the auxiliary agent before and after coating the AA-PVA composition of the present invention is possible. Glyoxal, methylolmelamine, potassium persulfate, ammonium persulfate, sodium persulfate and ferric chloride as auxiliaries,
Metal salts such as magnesium chloride, ammonium chloride, formalin, glycine, glycidyl ester, glycidyl ether, dimethylol urea, ketene dimer, boric acid,
Those using a known compound as a waterproofing agent for AA-PVA such as borax can significantly improve the water resistance without lowering the sticking prevention performance and the residue adhesion prevention performance.

Further, it is optional to use known additives such as thermoplastics such as higher fatty acid amides, fillers such as calcium carbonate and titanium dioxide, and dispersants. Coating can be performed by any means. The concentration of the coating liquid is appropriately 1 to 10% by weight in consideration of coatability and the like. The coating amount is 0.5-5
About g / m ² is preferable. After coating, the desired protective layer is formed by air-drying or mild heat treatment.

It is also useful to use the paper processing agent of the present invention as a binder component in a heat-sensitive layer for heat-sensitive recording paper, and this case will be described below. Technically, in the description of the method for forming the protective layer. It is almost the same as the contents of the process of forming the thermosensitive recording layer. Although overlapping, it will be described in detail again.

In preparing a coating composition using the above binder, an aqueous dispersion of a color-forming substance and an aqueous dispersion of a color developer are separately prepared, and they are sufficiently stirred to be slightly stirred. After crushing, a uniform dispersion coating liquid can be obtained simply by mixing and stirring both liquids. The AA-PVA composition of the present invention is added to at least one of an aqueous dispersion of a color forming substance and an aqueous dispersion of a developer.

The AA-PVA composition of the present invention is suitably 10 to 200% by weight based on the total amount of the color-forming substance and the color developer. The solid content concentration of the coating liquid is selected from the range of 10 to 40% by weight in consideration of workability. In addition, the coating liquid contains glyoxal, methylolmelamine, potassium persulfate, ammonium persulfate, sodium persulfate, metal salts such as ferric chloride and magnesium chloride, and compounds known as waterproofing agents for AA-PVA such as ammonium chloride. Further, it is optional to add known additives such as thermoplastics such as higher fatty acid amides, fillers such as calcium carbonate and titanium dioxide, and dispersants. AA as a binder
It is also possible to mix and use a binder other than the modified PVA, for example, PVA, modified PVA such as PVA containing a carboxyl group, methyl cellulose, carboxymethyl cellulose, starches, and latexes. The paper to be coated with the coating liquid is not particularly limited, and any paper can be used.

For coating, any known method such as a roll coater method, an air-coater method, or a blade coater method may be used. Therefore, the coating amount of the coating liquid is 1 to 20 g / m ^2, especially 3 to 10 g / m ^2.
It is appropriate to set it to a degree.

The application of the AA-PVA composition of the present invention as a paper-processing agent is not only for thermal recording paper overcoating agents and binders, but also for information industry paper such as ink jet recording paper or manila balls, white balls and liners. It is also applied to clear coating of any paper such as paperboard of general, high-quality paper, printing paper such as gravure paper, pigment coating agent, etc., the coating method, type of additive, addition amount of thermal recording paper overcoat It is similar to the case.

Further, the paper-processing agent of the AA-PVA composition of the present invention may also be used as a sizing agent. In this case, the AA-modified PVA composition of the present invention can be added to a conventionally known ketene dimer, natural wax, surfactant or the like. The PVA composition can be used by adding 5 to 50% by weight. At this time, in order to further improve the yield, it is desirable to use a cationic polymer as a fixing agent. The cationic polymer is preferably cationized starch, cationized cellulose, polyamide-based polymer, polyethyleneimine, polyvinyl pyridine and its quaternized product, polydimethylaminoethyl methacrylate and its quaternized product, and these cationic monomers and acrylamide. Examples thereof include copolymers of

The sizing agent has a solid content of 0.01 to 2% by weight, preferably 0.05 to 1% by weight, based on the weight of pulp.
Is added. It goes without saying that the addition level of these sizing agents is adjusted according to the sizing degree required by the target paper. The size composition used here is used in the form of being dispersed in water, and the particle size of the size particles dispersed in water is 5 μm or less, preferably 1 μm or less. If the particle size is larger than 5 μ, the stability of the dispersant may be impaired or the size effect may be deteriorated.

Although the application as a paper processing agent has been described above, the AA-PVA composition of the present invention is also useful as an adhesive, and the application will be specifically described.

Examples of the adhesive using the AA-PVA composition of the present invention include general adhesives containing PVA in an aqueous solution,
It can be used for various adhesives such as rewetting adhesives, hot melt adhesives, pressure-sensitive adhesives, and quick-setting adhesives (honeymoon adhesives). As a general aqueous solution adhesive application,
The content of the composition is about 1 to 30% by weight, a filler,
Additives such as an antifoaming agent (or a foaming agent) and a coloring agent are blended to be used for an adhesive.

When used as a rewetting adhesive, the AA-PVA composition of the present invention is made into an aqueous solution, and then coated on a substrate such as gum tape or stamp and dried. On this occasion,
Alcohol such as methanol or ethanol, if necessary
Glycols such as ethylene glycol, propylene glycol, polyethylene glycol and glycerin may be added. The coating can be performed by a known method such as a gravure coater, a reverse roll coater, an air knife coater, and a spray.

It is also possible to form a rewetting adhesive layer by hot-melt coating. At this time, the AA-ized PVA composition of this invention is 100-200.
The resin is melted at about 0 ° C., and additives such as a plasticizer (polyhydric alcohols such as ethylene glycol and propylene glycol and higher fatty acid esters thereof) are added to the roll coater to have a viscosity of 500 to 10,000 cps, The substrate can be coated by a known method such as a doctor coater or spray.

As for the hot melt adhesive, it is possible to add additives such as a plasticizer and the like to apply it to a base material by a known method in the same manner as described above, and use it for binding bookbinding, packaging, woodworking, fibers and the like. .

As the pressure-sensitive adhesive, a plasticizer, a pressure-sensitive adhesive or the like as described above may be added and coated on a substrate by a known method to be used for bonding a label, a tape or the like. As the fast-curing adhesive (honeymoon adhesive), liquid A comprising an aqueous liquid containing the AA-PVA composition of the present invention and an amine compound (melamine, acetoguanamine, benzoguanamine, urea, alkylated methylolurea, alkyl) Methylol melamine, condensates of acetoguanamine and benzoguanamine with formaldehyde, aliphatic amines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, trimethylhexamethylenediamine, polyetherdiamine, metaphenylenediamine,
Aromatic amines such as diaminodiphenylmethane, amine adducts, modified amines such as polyamidoamine), aldehyde compounds (formaldehyde, acetaldehyde,
Monoaldehydes such as propionaldehyde, butyraldehyde, glyoxal, glutandialdehyde, malondialdehyde, dialdehydes such as succindialdehyde, maleindialdehyde, phthaldialdehyde, etc., hydrazine compounds (hydrazine, hydrazine hydrate, hydrazine hydrochloride) , Inorganic salts such as sulfuric acid, nitric acid, nitrous acid, phosphoric acid, thiocyanic acid, carbonic acid, etc. and organic salts such as formic acid, oxalic acid, etc. Monosubstituted hydrazine such as methyl, ethyl, propyl, butyl, allyl, 1,1- Dimethyl,
Asymmetric disubstituted products such as 1,1-diethyl, 4-n-butyl-metal and 1,2-dimethyl, 1,2-diethyl,
Symmetric disubstituted products such as 1,2-diisopyr).

Formamide group-containing compounds (monomer polymers such as vinylformamide, N-allylformamide, acrylformamide, etc. or copolymers of these monomers with vinyl acetate monomers, styrene monomers, methyl (meth) acrylate etc.), isocyanates Compounds (tolylene diisocyanate, hydrogenated tolylene diisocyanate, trimethylolpropane-tolylene diisocyanate adduct, triphenylmethane triisocyanate, methylenebis-4-phenylmethane triisocyanate, methylenebisisophorone diisocyanate, methylenebis-4-phenylmethanetriisocyanate Isocyanates and methylenebisisophorone diisocyanate ketoxime blocks), polyvalent metal ions (aluminum acetate, copper acetate, chloride) Luminium, copper chloride, lead chloride, cobalt chloride, iron (III) chloride, aluminum sulfate, iron (III) sulfate, etc.) and other B-containing solutions containing methylol group or alkoxymethyl group-containing compound The liquid A is an aqueous solution or emulsion of the AA-PVA composition of the present invention. In the case of an aqueous solution, the content of the composition is preferably 2 to 50% by weight, and in the case of an emulsion, 1 to 10% by weight. preferable.

In preparing the emulsion, although not particularly limited, the AA-PVA composition of the present invention is used as an emulsifier or a protective colloid for vinyl monomers (vinyl acetate, (meth) acrylic acid). Ester, vinyl chloride, etc.), a method of post-emulsifying a solution or a melt of a synthetic resin (polyvinyl acetate, polyvinyl chloride, etc.) in the presence of the AA-PVA composition, and any method. Examples of the method include adding the AA-PVA composition of the present invention to a synthetic resin (polyvinyl acetate, polyvinyl chloride, etc.) emulsion to obtain a more stable emulsion.

If necessary, other water-soluble polymers such as PVA and starch, crosslinking agents such as polyvalent metals, isocyanates and amino resins, plasticizers, film-forming aids such as high boiling point solvents, calcium carbonate and clay. The above-mentioned solution A is obtained by adding an extender pigment such as the above, a colored pigment such as titanium oxide, an antiseptic, an insect repellent, an antifoaming agent, a thickener, a rust preventive and the like. In addition to the above compounds, the liquid B may further contain a curing accelerator such as amines, alcohols and acids, an anticorrosive such as lecithin and lanolin, an antiseptic, a thickener and the like. When using a fast-curing adhesive (honeymoon adhesive), it is sufficient to apply the above-mentioned liquids A and B to the adherend, respectively, and then bring the coated surfaces into close contact. In some cases, liquids A and B It is also possible to mix and use.

The application as an emulsion dispersion stabilizer, a paper processing agent, and an adhesive has been described above. The AA-PV of the present invention has been described above.
The composition A is useful in addition to the above applications, and specific applications include the following.

(1) Molded products Fiber, film, sheet, pipe, tube, leak-proof film,
Temporary film, for chemical lace, water-soluble fiber

(2) Coating agent-related sizing agents for textile products, warp sizing agents, textile finishing agents, leather finishing agents, paints, antifogging agents, metal corrosion inhibitors, brighteners for galvanizing, antistatic agents, conductive agents , Temporary film (3) Hydrophobic resin blending agent antistatic agent for hydrophobic resin, hydrophilicity-imparting agent, composite fiber, film and other additives for molded articles (4) Suspension dispersion stabilizer-related paint, India ink, Aqueous color, pigment dispersant such as adhesive, dispersion stabilizer for suspension polymerization of various vinyl compounds such as vinyl chloride, vinylidene chloride, styrene, (meth) acrylate and vinyl acetate.

(5) Thickener-related Thickeners for various emulsions (6) Flocculant-related Flocculants for suspended solids and dissolved substances in water, pulp and slurry drainage (7) Soil conditioner-related (8) Photosensitization Agents, electrosensing (9) Other ion exchange resins, ion exchange resins, ion exchange membranes, chelate exchange resins

[0059]

[Working] Since the AA-PVA composition of the present invention contains 8% by weight or less of methyl acetoacetate, it is less colored, has excellent stability of its aqueous solution, and is an emulsion produced when used as an emulsion dispersion stabilizer. It has good stability and little coloration, and is useful as an emulsion dispersion stabilizer. It also has good performance as a paper processing agent, especially as an overcoat agent for thermal recording paper, and is also useful as a paper processing agent. It has a good adhesive strength when used in a formulation and is also useful as an adhesive.

[0060]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the examples, "parts" means "parts by weight" and "%" means "% by weight" unless otherwise specified.

Example 1 100 parts of PVA powder (saponification degree 99.4%, polymerization degree 1200, average particle size 100 mesh) was charged into a kneader,
60 parts of acetic acid was put into this, swelled, rotation speed 20 rpm
The mixture liquid of 25 parts of diketene and 2 parts of acetic acid was added dropwise to the mixture while stirring at 60 ° C. over 4 hours, and the mixture was further reacted for 30 minutes. To the reaction dispersion after completion of the reaction, 0.035 parts of methyl acetoacetate was added, stirred for 30 minutes, washed with 400 parts of methanol, filtered, and dried at 70 ° C. for 6 hours. Degree of AA 6.
A powder of 0 mol% AA-PVA composition was obtained. The following performances (1) to (4) were evaluated for the obtained AA-PVA composition.

(1) Colorability The colorability of the powder of the obtained AA-PVA composition was visually evaluated as follows. ○: There is no difference in color from the raw material PVA. △: Coloring is not observed when viewed alone, but raw PV
A slight coloration is recognized as compared with A. X: Clearly yellow coloring is recognized as compared with the raw material PVA. (2) Stability of Aqueous Solution and Powder The stability of the viscosity of the aqueous solution of the obtained AA-PVA composition was evaluated as follows. Stability of Aqueous Solution Prepare a 4% aqueous solution of the above-mentioned AA-PVA composition at 25 ° C.
The viscosity (a) in Example 1 was measured with a Brookfield viscometer [(rotor number 5 rpm of rotor (No. 1)]], and then the aqueous solution was left in a constant temperature bath at 40 ° C. for 2 weeks. The viscosity (b) of the aqueous solution after standing was measured in the same manner as (b) /
The viscosity ratio is shown in (a).

Stability of powder The powder of the above-mentioned AA-PVA composition was treated at 60 ° C. and 65% RH.
After standing in a thermostatic chamber for 3 months, a 4% aqueous solution was prepared, and the viscosity (c) was measured in the same manner as above. Stability (c) /
It evaluated by (a). Table 1 shows the results.

(3) Performance of emulsion 60 parts of water in a separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, and the AA-modified PV obtained above
A composition of 4 parts and sodium acetate as a pH adjuster of 0.
03 parts and 10 parts of vinyl acetate monomer were charged, and the temperature in the flask was raised to 60 ° C. while stirring. During that time, 2 ml of a 1% ammonium persulfate aqueous solution was added while displacing the inside of the flask with nitrogen gas to initiate polymerization. Initial polymerization was carried out for 30 minutes, and the remaining 30 parts of vinyl acetate monomer was added to 3 parts.
The solution was added dropwise over a period of time, and 6 ml of a 1% aqueous solution of ammonium persulfate was divided into 4 portions every hour for polymerization. Then, aging at 75 ° C for 1 hour and then cooling to obtain a solid content of 41%.
A vinyl acetate emulsion was obtained. The emulsion had good fluidity. Regarding the obtained emulsion, the presence or absence of coarse particles having a particle size of 200 mesh or more, the viscosity,
Coloring, freezing stability, leaving stability, and structural viscosity index were evaluated as follows.

Viscosity The viscosity at 25 ° C. was measured with a Brookfield type rotational viscometer at a rotor rotation speed of 10 rpm.

Coloring The color of the powdered PVA of Example 1 before AA was visually compared with the emulsion produced by the above method, and those of equivalent color were not colored, and those of colored were colored. I decided.

Freeze stability 100 g of emulsion was placed in a 100 ml polyethylene container, left at -15 ° C for 24 hours, then left in a constant temperature water bath at 30 ° C for 1 hour, and then stirred with a glass rod to visually observe the appearance of the emulsion. It was observed and evaluated according to the freeze-thaw stability classification of JIS K 6828 as follows. ○ −−− No change. △ ----- Although there is a change, it returns to the original when stirred at high temperature. × −−− There is a change and it does not return to the original state even when stirred at high temperature.

Leaving stability About 50 g of emulsion was placed in a 50 ml polyethylene container and left in a thermostat at 60 ° C. for 7 days, after which it was stirred with a glass rod to form an emulsion into a clean glass plate with a glass rod. A thin coat was applied uniformly, and immediately the presence or absence of coarse particles was visually inspected and evaluated as follows. ○ --- Good fluidity, good coatability of emulsion, and no coarse particles. Δ −−− Good flowability and good coatability of emulsion, but some coarse particles are recognized. × −−− Thickened particles having no fluidity, being difficult to take out from the container, and having poor emulsion coatability. Many coarse particles are recognized.

Structural Viscosity Index The viscosity at 25 ° C. was measured with a Brookfield rotational viscometer at rotor rotation speeds of 2.0 rpm and 20 rpm, and the viscosity was calculated by the following formula. Structural viscosity index: log ₁₀ (viscosity value at 2.0 rpm / 2
Viscosity value at 0 rpm) These results are shown in Table 2.

(4) Performance of coating liquid for heat-sensitive recording paper The pot life of the coating liquid for heat-sensitive recording paper containing the AA-PVA composition of the present invention and the heat-sensitive recording paper coated with the coating are evaluated as follows. Went to. Liquid A Crystal violet lactone 10 parts AA-PVA 5% aqueous solution 10 parts 40% SBR latex 5 parts Water 15 parts Liquid B bisphenol A 50 parts AA-PVA 5% aqueous solution same as liquid A 50 parts Water 75 parts

The liquids A and B were separately pulverized with a sand grinder until the average particle size became about 3 μ, and then the liquids A and B were crushed.
The solution, 30 parts of clay, and 200 parts of the same 15% aqueous solution of PVA used in each solution were mixed to obtain a coating solution.

On the other hand, the coating liquid was applied onto a base paper having a basis weight of 50 g / m ² so that the coating amount after drying was 5.0 g / m ² and dried. Furthermore, a 10% aqueous solution of the above-mentioned AA-PVA composition was used at 5 g / m using a Dickson coater.
² (net) was overcoated and air-dried to obtain a heat-sensitive recording paper. The print color density of the recording paper, the plasticizer resistance, and the adhesion of dross on the thermal head were evaluated by the following methods.

Print color density 120 ° C., 2 kg by a thermal gradient tester (manufactured by Toyo Seiki Co., Ltd.)
/ Cm ² , the color is printed under the condition of 10 seconds, and the color density of the print is measured by a Macbeth densitometer (Macbeth RD-100R).
Type, using an amber filter).

Plasticizer resistance 20 g / c of printed recording paper is sandwiched between soft vinyl chloride sheets.
A weight of m ² was added and the mixture was allowed to stand for 168 hours, and the color density with respect to the original reaction density was calculated as a residual color ratio in%.

Deposition of thermal head residue A continuous 100 m grid pattern was printed with a facsimile machine to observe the occurrence of sticking and the degree of adhesion of the thermal head residue. Whiteness (ground stain) The whiteness was measured with a Hunter whiteness meter (using a blue filter). The results are shown in Table 3.

(5) Performance of Adhesive The storage stability and adhesiveness of the aqueous solution of the adhesive containing the AA-PVA composition were evaluated by the methods described below.

A 10% aqueous solution of the above-mentioned AA-PVA before standing and at 60 ° C. for 2 weeks was used as solution A, and its viscosity was measured with a Brookfield viscometer at a rotor rotation speed of 10 rpm at 25 ° C. Was measured to examine the storage stability of the aqueous solution. Further, a 5% aqueous solution of adipic acid dihydrazide was used as solution B, and 150 g / m ² of solution A and 50 g / m ² of solution B were applied to each of two pieces of 3 mm thick lauan plywood, and pressure was applied at 3 kgf / cm ² for 10 seconds. After JIS
Adhesive force was measured according to K 6852 (compressive shear adhesive strength test method for adhesives). Even if the solution A gelled, it was applied as it was, and the adhesive strength was measured in the same manner. The results are shown in Tables 4 and 5.

Example 2 100 parts of PVA powder (saponification degree 98 mol%, polymerization degree 1300, average particle size 200 mesh) was charged in a kneader,
While stirring at a rotation speed of 60 rpm, 15 parts of liquid diketene was added by spraying at room temperature for 30 minutes, and then the temperature was raised to 60 ° C. to react for 3 hours. After the reaction, methanol 100
The mixture was stirred for 30 minutes and then filtered at 60 ° C. for 8 minutes.
After drying for an hour, a powder of an AA-PVA composition containing 0.5% of methyl acetoacetate and having an AA-degree of 5.0 mol% was obtained, and evaluated in the same manner as in Example 1.

Example 3 PVA powder (saponification degree 98 mol%, polymerization degree 1700, average particle size 100 mesh) was charged into a reaction can equipped with a reflux condenser, 100 parts, acetic acid 100 parts, and methyl acetoacetate 40 parts. Then, 0.025 parts of tetrabutyl titanate was added thereto and reacted at 120 ° C. for 8 hours while stirring at a rotation speed of 20 rpm. After completion of the reaction, the mixture was cooled to 40 ° C., charged with 375 parts of methanol, stirred for 1 hour, filtered, and
It was dried at 50 ° C. for 6 hours under a reduced pressure of 0 mmHg, and contained 4% by weight of methyl acetoacetate and had an AA degree of 5.2 mol%.
A powder of the modified PVA composition was obtained and evaluated in the same manner as in Example 1.

Comparative Example 1 The procedure of Example 1 was repeated except that 10 parts of methyl acetoacetate was added after the completion of the AA-forming reaction. The powder of the AA-PVA composition of 0.0 mol% was obtained and evaluated in the same manner as in Example 1.

Comparative Example 2 In Example 3, after the reaction was completed, the reaction mixture was cooled to 40 ° C., charged with 375 parts of methanol, stirred for 1 hour, filtered, and dried at 50 ° C. for 6 hours.
Dried for an hour, containing 9.5% by weight of methyl acetoacetate, A
A powder of AA-PVA composition having a degree of A conversion of 5.2 mol% is obtained,
The evaluation was performed in the same manner as in Example 1.

The evaluation results of Examples and Comparative Examples are shown in Tables 1-5.

[Table 1] AA acetoacetic acid Stability of coloring viscosity Methyl (a) (b) / (a) (c) / (a) (mol%) (wt%) (cps) Example 1 6.0 0.03 ○ 13.2 3.5 1.2 Example 2 5.0 0.5 ○ 20.5 4.2 1.1 Example 3 5.2 4.0 ○ 25.0 3.8 1.5 Comparative Example 1 6.0 9.0 △ 11.7 ＊＊＊ Comparative Example 2 6.0 9.5 △ 23.5 ＊＊＊ ＊: Not measured due to gelation It was **: No measurement was performed because undissolved content was generated.

[0083]

[Table 2] Emulsion Viscosity Coloring Frozen Leave Structure viscosity (wt%) (PS) Stability Stability Stability Index Example 1 41.0 80 None ○ ○ 0.47 Example 2 40.5 220 None ○ ○ 0.49 Example 3 39.7 360 None ○ ○ 0.45 Comparative Example 1 38.8 30 Yes × × 0.31 Comparative Example 2 38.7 40 Yes × × 0.35

[0084]

[Table 3] Printing characteristics Plastic resistance Grazing adhesion Whiteness Color density (background stain) Example 1 1.48 95 Good 85.1 Example 2 1.45 93 Good 84.7 Example 3 1.43 90 Good 83.0 Comparative Example 1 1.30 75 Somewhat bad 64.3 Comparative Example 2 1.25 72 Bad 58.2

[0085]

[Table 4] Note) Before and after standing treatment means before standing and 6
10% of each AA-PVA after standing at 0 ° C for 2 weeks
Represents the viscosity of the aqueous solution.

[0086]

[Table 5] Initial adhesive strength (kg / cm ² ) Normal adhesive strength (kg / cm ² ) Before standing treatment After standing treatment Before standing treatment After standing Example 1 3.8 3.5 13.2 12.9 Implementation Example 2 4.2 3.8 3.8 15.5 14.3 Example 3 5.9 5.2 20.3 18.6 Comparative Example 1 2.2 1.8 6.5 4.2 4.2 Comparative Example 2 4.2 3.0 12.5 7.3 Note) The initial adhesive strength and the normal adhesive strength represent the adhesive strength immediately after pressure bonding and the adhesive strength after standing for 7 days at room temperature, respectively. The adhesive strength using each AA-ized PVA before processing and after standing for 2 weeks at 60 ° C. is shown.

[0087]

Since the AA-PVA composition of the present invention contains 8% by weight or less of methyl acetoacetate, it is less colored and has excellent stability in an aqueous solution, and an emulsion produced when used as an emulsion dispersion stabilizer. Has good stability and little coloring, and is also useful as an emulsion dispersion stabilizer.
In particular, the performance of an overcoating agent for heat-sensitive recording paper is good, it is useful as a paper processing agent, and the adhesive force when it is used as an adhesive is good, and it is also useful as an adhesive.

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[Procedure amendment]

[Submission date] July 9, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

However, there is a general belief that the AA-PVA is a resin that is more easily colored than conventional PVA, and there has been no attempt to improve this coloring much positively. The current situation. However, in recent years, AA-PVA has been used in a large amount in a wide range of applications due to its excellent properties, and improvement in coloring has also been required. Furthermore, the AA-ized P
In each application using VA, with the advancement of technology, higher quality physical properties, which had hardly been a problem in the past, are required, and for example, the aqueous solution used in the various applications described above is required. stability of the product emulsion when subjected to a further stability and emulsion dispersion stabilizer applications, paper processing agents, in particular performance when subjected to heat-sensitive recording paper of the overcoating agent, adhesive and the like when subjected to the adhesive It was found that there is still room for improvement.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction contents]

The emulsion polymerization using the AA-PVA composition of the present invention as an emulsion dispersion stabilizer and the emulsion obtained by such polymerization have been described above.
The emulsion dispersion stabilizer using the modified PVA composition is useful even when an emulsion is produced by the post-emulsification method. In this case, the dispersion stabilizer is dissolved in water and the solution or molten resin is dissolved in the dispersion stabilizer. May be added dropwise and stirred. No special measures such as heating are required for emulsification, but heating may be performed at about 45 to 85 ° C., if necessary.
The substance to be emulsified is not particularly limited, epoxy resin, urethane resin, urea-formaldehyde precondensate, phenol-formaldehyde precondensate, alkyd resin,
Ketene dimer, rosin, silicone resin, wax,
Examples include polyolefin resins and asphalt.
If necessary, various PVA and PV known as nonionic surfactants or emulsifiers such as polyoxyethylene-alkyl ether type, polyoxyethylene-alkylphenol type, polyhydric alcohol ester type and protective colloids.
A derivative or anionic field such as higher alcohol sulfate
In addition to the surface- active agent, various surface-active agents used in the above-mentioned emulsion polymerization can be used. Further, these surfactants can be mixed in the object to be emulsified, and, as described above, plasticizers such as phthalic acid ester and phosphoric acid ester, sodium carbonate, sodium acetate, phosphoric acid, etc. A pH adjusting agent such as sodium can also be used in combination.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location D21H 19/20 D21H 1/34 F

Claims (4)

[Claims] 1. A polyvinyl alcohol-based resin composition containing an acetoacetic acid ester group, which contains 8% by weight or less of methyl acetoacetate. 2. An emulsion dispersion stabilizer comprising the polyvinyl alcohol resin composition containing an acetoacetic acid ester group according to claim 1 as a main component. 3. A paper processing agent comprising the polyvinyl alcohol resin composition containing an acetoacetic acid ester group according to claim 1. 4. An adhesive containing the polyvinyl alcohol resin composition containing an acetoacetic acid ester group according to claim 1.