JPH1149914A - Polyvinyl alcohol composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which emits less odor of the constituent polyvinyl alcohol, especially an odor called a fish odor and originating in a lower amine compound by mixing a polyvinyl alcohol having cationic groups in the molecule with a specified amount of a water-soluble metal sulfate. SOLUTION: It is desirable that the cation-modified polyvinyl alcohol has a content of cationic groups present in the molecule of 0.01-20 mol.% in terms of structural units, a degree of saponification of 70-100 mol.% and a degree of polymerization of 200-30,000. The water-soluble metal salt may be anything that itself is odorless and is water-soluble and colorless. Above all, from the viewpoint of safety and noncorrosiveness to equipment, it is desirably aluminum potassium sulfate or aluminum sodium sulfate. The mixing ratio is such that it is used in an amount of at most 10 pts.wt. per 100 pts.wt. cation-modified polyvinyl alcohol. There is no particular limitation on the method for producing the composition. Also, various additives may be added to the composition within the scope not detrimental to the effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composition in which the odor of a cation-modified polyvinyl alcohol is reduced.

[0002]

2. Description of the Related Art Cation-modified polyvinyl alcohol (hereinafter abbreviated as "cation-modified PVA") is a nonionic polyvinyl alcohol containing a cation group. As a method for producing the cation-modified PVA, a method such as Japanese Patent Publication No. 62-34242 has been proposed. Cation-modified PV produced by these methods
A has reactivity with various anionic substances, and has a high yield to paper during paper making. Therefore, A has a coating agent for ink jet printing, a paper-enhancing agent for internal additive, an emulsifying and dispersing agent for cationic emulsion, and polymer aggregation. It is widely used as an agent, a dehydrating agent, a wall material for microcapsules, a laundry paste, a cheese paste, a binder for inorganic substances such as rock wool, a binder for water-based paints, a catcher for anionic compounds, and the like. However, cation-modified PVA is PVA
Modifier and PV Used for Providing Cationic Group to PVA
A major problem is that the cationic group chemically bonded to A is partially decomposed with heat treatment, light irradiation, and time, thereby generating an odor derived from a lower amine compound generally called "fish odor".

[0003]

DISCLOSURE OF THE INVENTION The present invention relates to a "fish odor" by a lower amine compound generated from a cation-modified PVA.
It is intended to solve the odor problem referred to as "odor problem".

[0004]

Means for Solving the Problems As a result of intensive studies on the above-mentioned problems, the present inventors have found that a polyvinyl alcohol having 100 parts by weight of a polyvinyl alcohol (A) having a cationic group in the molecule and 10 parts by weight or less of a water-soluble metal sulfate is used. The present inventors have found an alcohol composition and completed the present invention.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The cation-modified PVA (A) of the present invention is produced by a method based on copolymerization or a method based on post-modification.
As a method by copolymerization, a monomer containing vinyl acetate and a quaternary ammonium salt such as (meth) acrylamido-propyl-trimethylammonium chloride is lumped, a solution,
A method of saponifying polyvinyl acetate obtained by copolymerization by a known polymerization method such as suspension and emulsification; copolymerization of vinyl acetate and an amino group-containing monomer such as dimethylaminoethyl (meth) acrylamide, followed by chlorination. A method in which a known quaternizing agent such as methyl is added to quaternize the amino group and then saponified; a copolymer of vinyl acetate and an amino group-containing monomer such as dimethylaminoethyl (meth) acrylamide is usually used. And saponifying the amino group with a known quaternizing agent; polyvinyl acetate obtained by copolymerizing vinyl acetate with N-vinyl succinimide or N-vinyl phthalimide. After saponification by a method, a method in which an imide group is further decomposed with an alkali or hydrazine may be mentioned. Post-denaturing methods include the existing P
VA has a quaternary ammonium group and an aldehyde group,
Examples include a method of reacting a low molecular weight compound having a reactive group such as an epoxy group and a silanol group, a method of adding acrylamide to PVA, and then subjecting the acrylamide unit to Hoffman decomposition.

The content of the cation group present in the molecule of the cation-modified PVA is 0.01 to 20 mol% in constitutional unit,
Preferably it is 0.03 to 10 mol%, still more preferably 0.05 to 5 mol%. When the content of the cationic group present in the molecule is less than 0.01 mol% in the constitutional unit, the effect of cationizing the molecule is reduced. On the other hand, even if the content of the cationic group present in the molecule is higher than 20 mol% in the constitutional unit, there is no significant difference in the performance as compared with a modified PVA of less than that, and the production cost increases.

The degree of saponification of cation-modified PVA is as follows:
Although not particularly limited, it is preferably 70 to 100 mol%, more preferably 80 to 100 mol%. The polymerization degree of the cation-modified PVA is preferably 200 to 30,000,
250 to 20,000 is more preferable, and 300 to 10,
000 is even more preferred. Here, the polymerization degree of PVA is a viscosity average polymerization degree obtained from the viscosity of an acetone solution of polyvinyl acetate obtained by re-acetylating the PVA. The cation-modified PVA of the present invention may be further copolymerized with other monomers as long as it does not inhibit water solubility, and those obtained by modifying the polymer terminal with a chain transfer agent can also be used. .

Next, the water-soluble metal sulfate (B) of the present invention will be described. As the water-soluble metal sulfate used in the present invention, any water-soluble and colorless metal sulfate which does not have an odor of itself and is water-soluble can be used. Of these, alums composed of magnesium sulfate, potassium aluminum sulfate or sodium aluminum sulfate are particularly preferred from the viewpoint of safety and corrosiveness of the device.

The amount of the water-soluble metal sulfate relative to the cation-modified PVA is 10 parts by weight or less, preferably 0.001 to 1 part by weight, per 100 parts by weight of the cation-modified PVA.
0 parts by weight, more preferably 0.001 to 5 parts by weight, even more preferably 0.01 to 1 part by weight. An appropriate amount of the water-soluble metal sulfate of the present invention is a cationically modified PV.
Determined by the amount of the cationic group contained in A and the type of the cationic group. When the amount of the cationic group is large or when a readily decomposable cationic group is used, a larger amount of the water-soluble metal sulfate is required. Becomes When the amount of the cationic group contained in the cation-modified PVA to be compounded is small, the compounding amount of the water-soluble metal sulfate of the present invention can provide a sufficient effect even if the compounding amount is less than 0.001 part by weight, but industrially When producing a blend, the blending amount is 0.001 from the viewpoint of blending accuracy.
It is preferably at least part by weight. Even if the amount of the water-soluble metal sulfate of the present invention is more than 10 parts by weight, the effect does not increase,
It is not preferable because problems such as a decrease in physical properties and an increase in cost due to a decrease in the PVA concentration of the composition itself and a side reaction such as gelation may occur.

The method for producing the polyvinyl alcohol composition of the present invention is not particularly limited.
A method of blending a powdered water-soluble metal sulfate with A powder; a method of spraying and mixing a water-soluble metal sulfate aqueous solution to a cation-modified PVA powder; a method of dissolving a water-soluble metal sulfate in a cation-modified PVA aqueous solution; A method of adding a water-soluble metal sulfate when melt-kneading hot-melt cation-modified PVA; a method of applying a water-soluble metal sulfate to a film using the cation-modified PVA; For example, a method in which a water-soluble metal sulfate is applied and mixed at the same time as the application of the cation-modified PVA is used. In addition, the polyvinyl alcohol composition of the present invention generally includes an antifoaming agent, an antistatic agent, a fungicide, a bactericide, a penetrant, an antioxidant, and an ultraviolet absorber that do not impair the effects of the present invention. Auxiliary agents such as a lubricant, a coloring agent, a filler, and a plasticizer may be used in combination. In using the composition of the present invention, other polymer compounds can be used in combination to such an extent that no problem is caused.

[0011]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the following, “parts” and “%” mean “parts by weight” and “% by weight”, respectively, unless otherwise specified. In the following examples, the degree of polymerization of PVA means that the PVA is re-acetylated by a normal method,
It is a value calculated from the intrinsic viscosity (unit: dl / g) in acetone at ° C using the following formula. Degree of polymerization = ([η] × 10 ³ /7.94) ^{(1 / 0.62)}

(Synthesis of cation-modified PVA) After vinyl acetate and (meth) acrylamido-propyl-trimethylammonium chloride are solution-copolymerized in methanol,
Methanol vapor was blown into the reaction solution, and a methanol solution of sodium hydroxide was added to a methanol solution of polyvinyl acetate obtained by driving out unreacted monomers, mixed well, and then allowed to gel for a certain period of time. Next, the gel is pulverized, washed with methanol, and dried to a volatile content of 5% or less, whereby the polymerization degree is 1700, the saponification degree is 88.2 mol%, the cation modification degree is 3 mol%, and the sodium acetate content is 0%. 0.35% of cation-modified PVA was obtained. This is CP
Called VA1.

In the same manner as for C-PVA1, a polymerization degree of 17
00, saponification degree 88.0 mol%, cation modification degree 1.0
Thus, PVA having a mol% of sodium acetate and a content of 0.38% was obtained. This is called C-PVA2.

In the same manner as for C-PVA1, a polymerization degree of 56
0, PVA having a saponification degree of 88.1 mol%, a cation modification degree of 0.5 mol%, and a sodium acetate content of 0.42% was obtained.
This is called C-PVA3.

In the same manner as for C-PVA1, a polymerization degree of 34
00, saponification degree 87.7 mol%, cation modification degree 0.1
Thus, PVA having a mole% of sodium acetate and a content of 0.43% was obtained. This is called C-PVA4.

After vinyl acetate and N- (3-dimethylaminopropyl) methacrylamide are copolymerized in a methanol solution in methanol, methanol vapor is blown into the reaction solution to drive out unreacted monomers to obtain polyvinyl acetate. After bubbling methyl chloride gas in the methanol solution for 3 hours, it is saponified in the same manner as C-PVA1, and has a polymerization degree of 1700, a saponification degree of 87.4 mol%, a cation modification degree of 1 mol%, and a sodium acetate content of 0. 33% of PVA was obtained. This is called C-PVA5.

(Measurement of Odor) Room temperature method A well-washed, dried, 500-ml glass sealed container, which has been confirmed in advance to have no odor, is charged with 100 g of the cation-modified PVA powder obtained by the above method and various water-soluble metal sulfates. After one week, the internal odor was organoleptically evaluated. The evaluation result was 0, 2,
The symbols 4, 6, 8, and 10 are shown in Tables 1 and 2. 2. Heating method A container for odor evaluation prepared in the same
After being left for a week, it was further left for 1 hour in a dryer at 90 ° C., and the internal odor was organoleptically evaluated. The evaluation results are shown in Tables 1 and 2 with symbols 0, 2, 4, 6, 8, and 10 in order of decreasing odor.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

According to the present invention, the odor of cation-modified polyvinyl alcohol, particularly the odor derived from a lower amine compound called "fish odor" can be greatly reduced, so that the industrial value is extremely high. Things.

Claims (4)

[Claims] 1. A polyvinyl alcohol composition comprising 100 parts by weight of polyvinyl alcohol (A) having a cationic group in a molecule and 10 parts by weight or less of a water-soluble metal sulfate. 2. A polyvinyl alcohol composition comprising 100 parts by weight of polyvinyl alcohol (A) having a cationic group in a molecule and 0.001 to 10 parts by weight of a water-soluble metal sulfate. 3. The polyvinyl alcohol composition according to claim 2, wherein the water-soluble metal sulfate is magnesium sulfate. 4. The polyvinyl alcohol composition according to claim 2, wherein the water-soluble metal sulfate is an alum comprising potassium aluminum sulfate or sodium aluminum sulfate.