JP2000344990A - Polyvinylamine salt and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyvinylamine salt improved in solubility to organic solvents and useful as an additive in each field of fiber, adhesive, etc., and as a water-resistant agent for paper for ink jet by including a specific polyvinylamine and a specific organic acid. SOLUTION: This polyvinylamine salt comprises (A) a polyvinylamine containing >=20 mol.% vinylamine structure unit represented by the formula, expressed by neutral amine and (B) at least one kind of organic acid represented by the formula R1-COOH [R1 is a (substituted)1-10C alkyl or alkenyl] in an amount of 10-100% based on the amino group in a form of an isolated acid as a counter salt for the component A. The organic acid is preferably at least one kind of acid selected from acetic acid, lactic acid and propionic acid. The component A is preferably obtained by hydrolyzing a (co)polymer such as N- vinylformamide or N-vinylacetamide or by Hofmann reaction of polyacrylamide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polyvinylamine salt. More specifically, the present invention relates to a polyvinylamine salt having improved solubility by containing at least one organic acid selected from acetic acid, lactic acid, propionic acid and the like as a counter salt of polynylamine with respect to an amino group in an amount of 10 to 100%. In addition, in this specification, polyvinylamine is a general term for a polymer containing a vinylamine structural unit.

[0002]

2. Description of the Related Art The use of polyvinylamine as a water-soluble polymer containing a primary amino group at high density has been studied in various fields such as dyeing, papermaking, and film. Polyvinylamine forms salts with various acids as a primary amine. At present, polyvinylamine hydrochloride is mainly used because of its cost and ease of synthesis. However, although the hydrochloride of polyvinylamine is soluble in water at an arbitrary concentration, it is hardly soluble in an organic solvent within a practical range. Therefore, it cannot be used in a system in which an organic solvent is mixed.

In practice, when preparing a coating solution containing polyvinylamine on a film, paper, or the like, it may be desirable to add an additive dissolved in an organic solvent such as methanol or ethanol for the purpose of improving various physical properties. . At this time, since the solubility of the polyvinylamine hydrochloride in the organic solvent is low as described above, the polyvinylamine salt is precipitated simultaneously with the addition of the organic solvent solution of the additive, and as a result, the additive is added. There was a problem that I could not do it. In order to solve this problem, it is necessary to synthesize a polyvinylamine salt having solubility in an organic solvent.
As one method of improving the solubility, modification by copolymerizing a hydrophobic monomer with polyvinylamine can be considered.

However, polyvinylamine is generally synthesized by hydrolyzing a precursor polymer (eg, poly-N-vinylformamide, poly-N-vinylacetamide) with strong acidity and strong basicity. However, even when a monomer such as an acrylic ester having the above formula is introduced by copolymerization, there is a problem that the hydrophobic component is decomposed during hydrolysis with a strong acid or strong base. Further, monomers that can withstand hydrolysis by strong acids and strong bases such as styrene have poor copolymerizability with N-vinylformamide and N-vinylacetamide, making it difficult to obtain a uniform polymer.

[0005]

As described above, the conventional polyvinylamine hydrochloride has a problem that its solubility in an organic solvent is poor when incorporated into a realistic formulation containing an organic solvent. There is a need for a polyvinylamine salt.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above circumstances, and as a result, the use of a specific organic acid as a counter salt of polyvinylamine has significantly improved the solubility in organic solvents. The present invention has been found. That is, the gist of the present invention is to provide a polyvinylamine containing at least 20 mol% of a vinylamine structural unit represented by the following formula (1):

[0007]

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The opposite salt of polyvinylamine is represented by the following formula (2)

[0009]

Embedded image R ¹ —COOH (2)

(In the formula (2), R ¹ represents an alkyl or alkenyl group having 1 to 10 carbon atoms which may have a substituent.)
A polyvinylamine salt, which is contained in an amount of 10 to 100 mol% based on the amino group.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The polyvinylamine salt of the present invention is a polyvinylamine containing 20 mol% or more of a vinylamine structural unit represented by the following formula (1) in the form of a neutral amine.

[0012]

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As a counter salt of the polyvinylamine, the following formula (2) in the form of a free acid:

[0014]

Embedded image R ¹ —COOH (2)

(In the formula (2), R ¹ represents an alkyl group or an alkenyl group having 1 to 10 carbon atoms which may have a substituent.)
It contains 10 to 100 mol% based on the amino group. As the substituent on the alkyl group or alkenyl group for R ^1, a halogen or a hydroxyl group is usually preferred. The organic acid used in the present invention forms a salt with polyvinylamine to improve the solubility in an organic solvent. Specifically, acetic acid, chloroacetic acid, cyanoacetic acid, and dichloroacetic acid are used. , Trichloroacetic acid, trimethylacetic acid, fluoroacetic acid, bromoacetic acid, lactic acid, nonanoic acid, pyruvic acid, hexanoic acid, heptanoic acid, propionic acid, 2-
Examples thereof include chloropropionic acid, 3-chloropropionic acid, valeric acid, butyric acid, isovaleric acid, isobutyric acid, and octanoic acid. Among these, acetic acid, lactic acid, butyric acid, propionic acid and the like can be mentioned as particularly advantageous acids from the viewpoint of price. The organic acid used in the present invention is two kinds or three kinds.
More than one species may be used in combination. The polyvinylamine to be used in the present invention, that is, a polyvinylamine containing at least 20 mol% of a vinylamine structural unit represented by the following formula (1)

[0016]

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Is, for example, N-vinylformamide, N
-Vinylacetamide, N-vinylphthalimide, N-
Those obtained by hydrolyzing a (co) polymer of vinyl carbamate or those obtained by the Hoffman reaction of polyacrylamide are generally used. The following method is exemplified as a method for producing polyvinylamine by polymerization and subsequent hydrolysis. N
-Explanation will be made by taking vinylformamide as an example.

As the polymerization method, any of ionic polymerization such as anionic polymerization and cationic polymerization and radical polymerization may be used, but radical polymerization is preferred because the molecular weight of the N-vinylformamide polymer can be easily controlled. .
As the polymerization initiator for radical polymerization, any of the usual general initiators can be used, but an azo compound is preferable in order to obtain a polymer in good yield. Particularly preferred initiators are hydrochloride and acetate of 2,2'-azobis-4-amidinopropane, sodium salt of 4,4'-azobis-4-cyanovaleric acid, azobis-N, N'-dimethyleneisobutyl Amidine hydrochloride and sulfate. The amount of the polymerization initiator to be used is usually 0.01 to 1% by weight based on the weight of the monomer.

The polymerization method for producing the N-vinylformamide polymer can be carried out by known methods such as bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization. The polymerization reaction is generally performed under an inert gas stream, usually at 30 to 100 ° C.
Is performed under the following temperature conditions. In the case of solution polymerization, water is used as a solvent, and polymerization is usually performed with an aqueous solution having a monomer concentration of 5 to 60% by weight. In the case of suspension polymerization, usually, an aqueous solution having a monomer concentration of 20 to 80% by weight is polymerized in a water-in-oil dispersion state using a hydrophobic solvent and a dispersion stabilizer. In the case of emulsion polymerization, usually, an aqueous solution having a monomer concentration of 20 to 60% by weight is polymerized in an oil-in-water type or water-in-oil type emulsion state using a hydrophobic solvent and an emulsifier.

In the polymer of the present invention, one or more monomers can be copolymerized as long as the properties of the polymer are not impaired. In this case, as the monomer used,
For example, (meth) acrylonitrile, (meth) acrylamide, N-substituted (meth) acrylamide, (meth) acryl esters, vinyl esters, vinyl ethers,
Nonionic monomers such as vinyl alcohol and allyl ether, (meth) acrylic acid, α, β-unsaturated dicarboxylic acid, sulfoalkyl (meth) acrylamide, sulfoalkyl (meth) acrylate, (meth) allylsulfonic acid, And anionic monomers such as salts thereof, and cationic monomers such as dialkylaminoalkyl (meth) acrylate, dialkylaminoalkyl (meth) acrylamide, allylamine, diallylamine and salts or quaternary ammonium compounds thereof.

The polymer used in the production method of the present invention is not limited by its molecular weight, but usually has a reduced viscosity of 0.01 to 10 as measured at 25 ° C. in 1N saline.
dl / g of linear polymer is used. The polymer thus obtained is subsequently hydrolyzed to obtain a polymer having a polyvinylamine unit.

In general, the polyvinylamine salt to be used in the present invention is theoretically hydrolyzed under acidic conditions of poly-N-vinylformamide and then neutralized into a free amine form (the following formula: (A)) Alternatively, it is obtained by hydrolyzing under a basic condition to form a free amine (formula (b) below) and then neutralizing a part or all of the free amine with an organic acid.

[0023]

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[0024]

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In addition to the above-mentioned method, a method of directly hydrolyzing poly-N-vinylformamide with an organic acid to obtain a target organic acid salt of polyvinylamine can be considered. In some cases the acidity is weak,
High temperature and pressure are required for hydrolysis.

[0026]

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As the denaturing agent used for the acidic hydrolysis, any compound which acts strongly acidic is used. For example, hydrochloric acid, bromic acid, hydrofluoric acid, sulfuric acid, nitric acid, phosphoric acid,
Sulfamic acid, methanesulfonic acid and the like can be mentioned, but monovalent acids are preferred from the viewpoint of solubility of the hydrolyzate in water.

As a method for converting polyvinylamine into a free amine type after acidic hydrolysis, a neutralization method using a base,
A method using a dialysis membrane, a method using an ion exchange resin, and the like are conceivable, but a neutralization method using a base is generally used in terms of cost advantage. When a large amount of inorganic salts generated by the neutralization is disliked to be mixed in the system, the inorganic salts can be removed by once performing purification such as reprecipitation purification.

As the modifier used for the basic hydrolysis, any compound which acts strongly basic is used. For example, sodium hydroxide, potassium hydroxide, lithium hydroxide, and quaternary ammonium hydroxide are exemplified. In the case of basic hydrolysis, formate derived from the formamide group (if the strong base is caustic soda, formate is sodium formate) is generated in the system, and the resulting polyvinylamine solution becomes a mixture with formate. If one does not want to mix the salts, it is necessary to introduce some purification step after base hydrolysis.

The amount of the modifying agent to be used is usually from 0.2 to 5 times the mol of the formyl group in the N-vinylformamide polymer, and is appropriately used according to the desired modification ratio. Since the polymer of the present invention is intended to be a polyvinylamine salt soluble in an organic solvent, it is necessary that at least 20 mol% of a polyvinylamine unit be present in the polymer. The reaction temperature during the hydrolysis is usually in the range of 50 to 110 ° C, and the reaction time is usually in the range of 1 to 8 hours.

During the hydrolysis, hydroxylamine hydrochloride is optionally added for the purpose of preventing gelation caused by impurities.
Denaturation may be performed by adding a gelling inhibitor such as hydroxylamine sulfate. In addition, hydrolysis can be performed after treatment with a gelling agent before denaturation. The hydrolysis is performed in a homogeneous solution system or a heterogeneous solution system. In the case of a homogeneous solution hydrolysis, for example, a solvent such as water or a mixed solvent of water and methanol is used. In the case of a heterogeneous system, a solvent such as hexane or toluene is used. In the case of N-vinylphthalimide, it may be hydrolyzed by a known method using hydrazine.

In the present invention, an organic acid salt is formed in the molecule by allowing the above-mentioned organic acid to act on the thus obtained free amine type polyvinylamine. The amount of the organic acid used for neutralization is usually selected in the range of 0.5 to 5 equivalents per polyvinylamine unit. At this time, it is not always necessary to substitute the organic acid salt with 100% since the purpose of converting the organic acid salt is to improve the solubility of the polyvinylamine salt in the organic solvent.

Further, after an appropriate organic solvent is added to the polyvinylamine organic acid salt once formed by neutralization and reprecipitation purification is carried out, it is dissolved again in demineralized water, and an organic acid is added to obtain a higher organic acid purity. Can be obtained. This operation can be repeated not only once but also twice and three times to increase the purity of the polyvinylamine organic acid salt. The thus obtained organic acid salt of polyvinylamine exhibits excellent properties as a water-proofing agent for ink-jet papers and films, a fixing agent for reactive dyes, an antistatic agent and the like.

[0034]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention.

<Production example of poly-N-vinylformamide> 1592 g of demineralized water was added to a 3 l jacketed separable flask equipped with a stirrer, a cooling tube, a thermometer, a dropping funnel and a nitrogen inlet tube, and the temperature was raised to 70 ° C. did. Next, under nitrogen atmosphere, 10% by weight V-50 (azo polymerization initiator)
50 g of the aqueous solution was added, and dropping of 833 g (7.03 mol) of a 60% by weight aqueous solution of N-vinylformamide was immediately started. Dropping was performed over 2 hours, and 1 hour after the start of dropping, 25 g of a 10% weight V-50 aqueous solution was added. After completion of the dropwise addition, the mixture was aged at 70 ° C. for 3 hours, and then the temperature was lowered to stop the reaction, thereby obtaining a 20% aqueous solution of N-vinylformamide polymer (polymer aqueous solution A). Reduced viscosity (ηsp / C) 0.5 dl / g measured at a temperature of 25 ° C. in 1N saline.

<Production Example of Polyvinylamine> Aqueous polymer solution A synthesized according to the production example of poly (N-vinylformamide) was placed in a separable flask with a jacket, equipped with a stirrer, a cooling tube, a thermometer, and a nitrogen introduction tube.
100 g (20 g of pure polymer) and 1.95 g of hydroxylamine hydrochloride are added, and the mixture is reacted at 50 ° C. for 1 hour under a nitrogen atmosphere. 46.8% by weight 35% aqueous sodium hydroxide solution
g (1.4 equivalents based on formamide groups in the polymer) was added, followed by heating and hydrolysis at 80 ° C. for 5 hours. An aliquot of the resulting solution is taken and a large amount of 10 wt% HCl (3
5%) / methanol to precipitate the polymer as a hydrochloride. The hydrolysis rate of the polymer was 94%. The hydrolysis rate was calculated from a colloid titration value of a product aqueous solution with a 1/400 normal aqueous solution of polyvinyl potassium sulfate at pH 2.5 using toluidine blue as an indicator.

<Synthesis of Polyvinylamine Salt> Example 1 Acetic acid was added to 100 g of a polyvinylamine solution synthesized according to a synthesis example of polyvinylamine until the pH of the solution became about 2 which was strongly acidic. A 10-fold volume of acetone was added to the solution to precipitate a polyvinylamine salt. The precipitated polymer was finely ground, filtered, and washed with acetone. The obtained pale yellow powder was dried at 50 ° C. for 3 hours to obtain the desired polyvinylamine acetate. The content of acetate in polyvinylamine salt was 75%. The content of organic acid in polyvinylamine organic acid salt was 13 C-N.
Quantification by MR.

Example 2 A lactic acid salt of polyvinylamine was obtained in the same manner as in Example 1 except that acetic acid was changed to lactic acid. The content of lactic acid contained in the polyvinylamine salt was 60%.

Example 3 The same operation as in Example 1 was repeated, except that acetic acid was replaced with propionic acid, to obtain a propionate of polyvinylamine. The content of propionic acid contained in the polyvinylamine salt is 65
%Met.

Comparative Example 1 The same operation as in Example 1 was carried out except that acetic acid was replaced with hydrochloric acid, to obtain a hydrochloride of polyvinylamine. The content of hydrochloric acid contained in polyvinylamine hydrochloride was 95%.

[0041]

[Table 1]

<Evaluation of Solubility of Each Poly (vinylamine) Salt in Organic Solvent> Using the polymers obtained in Examples 1 to 3 and Comparative Example 1, solubility tests were carried out in the following solvents. Table 2 shows the results. (Judgment criteria for solubility) ○: completely dissolved, △: some insoluble matter, ×: completely insoluble

[0043]

[Table 2]

The polymer of the present invention exhibited higher solubility in organic solvents than the polyvinylamine hydrochloride of Comparative Example.

[0045]

The polyvinylamine salt of the present invention has good solubility not only in water but also in organic solvents such as methanol and ethanol. Therefore, it is extremely effective as an additive in various fields such as fibers, adhesives, coatings, and paints, or as a waterproofing agent for inkjet paper.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takao Tadenuma 1000-term Kamoshida-cho, Aoba-ku, Yokohama-shi, Yokohama-shi F-term in Yokohama Research Laboratory, Mitsubishi Chemical Corporation 2H086 BA34 4J002 BJ00W BJ00X EF006 EF016 EF026 EF036 FD090 FD100 GH01 GS00

Claims (7)

[Claims] 1. A polyvinylamine containing 20 mol% or more of a vinylamine structural unit represented by the following formula (1) in the form of a neutral amine: As a counter salt of the polyvinylamine, in the form of a free acid, the following formula (2): R ¹ —COOH (2) (In the formula (2), R ¹ is a carbon atom which may have a substituent. A polyvinylamine salt comprising at least one organic acid represented by the formula (1-10), which represents an alkyl group or an alkenyl group; 2. The polyvinylamine salt according to claim 1, wherein the organic acid is at least one selected from acetic acid, lactic acid and propionic acid. 3. A free amine type polyvinylamine and a compound represented by the following formula (2): R ¹ —COOH (2) (In the formula (2), R ¹ represents a carbon number which may have a substituent.) The method for producing a polyvinylamine salt according to claim 1, wherein at least one kind of organic acid represented by 1 to 10 alkyl groups or alkenyl groups is reacted. 4. The following formula (3): (In the formula (3), R ² represents —H or —CH ₃ ) An aqueous polyvinylamine solution obtained by hydrolyzing a polymer or a copolymer having a structural unit of a basic condition under a basic condition is represented by the following formula: (2) R ¹ —COOH (2) (In the formula (2), R ¹ represents an alkyl group or an alkenyl group having 1 to 10 carbon atoms which may have a substituent.) After adding at least one organic acid represented,
The method for producing a polyvinylamine salt according to claim 1, wherein the polymer is precipitated. 5. An inkjet recording sheet using the polyvinylamine salt according to claim 1 or 2. 6. An inkjet coating liquid containing the polyvinylamine salt according to claim 1 or 2. 7. An antistatic agent comprising the polyvinylamine salt according to claim 1 or 2.