JP4819609B2 - Vinylpyrrolidone polymer composition - Google Patents

Description

  The present invention relates to a vinylpyrrolidone-based polymer composition, and more particularly to a vinylpyrrolidone-based polymer composition that improves storage stability and has a small decrease in molecular weight (K value) due to shear stress.

  Vinyl pyrrolidone polymers (PVP) such as polyvinyl pyrrolidone and vinyl pyrrolidone copolymers have features such as compatibility with the living body, safety, and hydrophilicity. Widely used in applications.

  This PVP is generally obtained by solution polymerization, and may be stored in a solution state, or may be stored in a solid state through a drying and pulverization process. However, PVP is generally known to have unstable storage stability regardless of its form. For example, physical properties such as molecular weight change over time during long-term storage or high-temperature storage. there were.

  In addition, when solid PVP is used after being pulverized into fine powder, the molecular weight is reduced when a large shear stress is applied to the PVP during the pulverization process. It was. In addition, for example, when preparing an emulsion of a PVP aqueous solution, the solution-like PVP requires high-speed stirring, but there is a problem that the molecular weight decreases due to shear stress accompanying high-speed stirring and the viscosity of the emulsion cannot be secured. (Patent Document 1).

In order to improve the storage stability of the PVP, it is known to blend guanidines with the PVP.
JP 2001-192457 A

  By adding guanidines to PVP as described above, the stability of PVP can be improved, and the storage stability is improved, but the reduction in molecular weight due to stress applied during grinding and stirring has been suppressed. Not in.

  The present invention has been made in view of the above circumstances, and provides a vinylpyrrolidone-based polymer composition that improves the stability of PVP and suppresses a decrease in molecular weight (K value) due to shear stress. It is the purpose.

  As a result of various studies on the phenomenon of molecular weight reduction of PVP due to shear stress, the present inventors have found that the addition of 2-pyrrolidone and ammonia is effective in suppressing molecular weight reduction, that is, K value reduction. In this case, the present inventors have found that the oxygen concentration in the gas phase has an effect on the decrease in molecular weight.

That is, the vinylpyrrolidone polymer composition of the present invention contains 1 to 10,000 ppm of one or more compounds selected from the group consisting of guanidines in a vinylpyrrolidone polymer having a K value of 80 or more , and 2 - we shall pyrrolidone comprising 1~5000ppm the 1000~30000ppm and ammonia.

  According to the present invention, the storage stability of PVP can be improved and the decrease in K value of PVP due to shear stress can be suppressed, so that the workability and operability during pulverization and stirring are improved, and solid PVP is obtained. It becomes easy to make fine powder, pulverize and prepare liquid PVP by high-speed agitation, making it easy to produce powders and emulsifiers for cosmetics and pharmaceuticals using this vinylpyrrolidone polymer composition. Can be increased.

  Below, one Embodiment of the vinylpyrrolidone type polymer composition (PVP composition) which has PVP as a main ingredient which concerns on this invention is described.

  The PVP used in the present invention is a homopolymer of vinyl pyrrolidone (usually N-vinyl-2-pyrrolidone) or a copolymer of vinyl pyrrolidone and any other polymerizable monomer. And obtained by a conventionally known production method such as solution polymerization using a radical polymerization initiator.

  Any polymerizable monomer that can be copolymerized with vinylpyrrolidone is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, alkyl esters of acrylic acid (methyl acrylate, ethyl acrylate, etc.), methacrylic acid, and the like. Alkyl esters of acids (such as methyl methacrylate and ethyl methacrylate), aminoalkyl esters of acrylic acid (such as diethylaminoethyl acrylate), aminoalkyl esters of methacrylic acid, monoesters of acrylic acid and glycol, monoesters of methacrylic acid and glycol (Such as hydroxyethyl methacrylate), alkali metal salts of acrylic acid, alkali metal salts of methacrylic acid, ammonium salts of acrylic acid, ammonium salts of methacrylic acid, aminoalkyl esters of acrylic acid Quaternary ammonium derivatives, quaternary ammonium derivatives of aminoalkyl esters of methacrylic acid, quaternary ammonium compounds of diethylaminoethyl acrylate and methyl sulfate, vinyl methyl ether, vinyl ethyl ether, alkali metal salts of vinyl sulfonic acid , Ammonium salt of vinyl sulfonic acid, styrene sulfonic acid, styrene sulfonate, allyl sulfonic acid, allyl sulfonate, methallyl sulfonic acid, methallyl sulfonate, vinyl acetate, vinyl stearate, N-vinylimidazole, N -Vinylacetamide, N-vinylformamide, N-vinylcaprolactam, N-vinylcarbazole, acrylamide, methacrylamide, N-alkylacrylamide, N-methylolacrylamide, N, N- Chi Ren bisacrylamide, glycol diacrylate, glycol dimethacrylate, divinylbenzene, glycol diallyl ether, and the like. These may use only 1 type and may mix two or more types and may be copolymerized with vinylpyrrolidone.

  The proportion of vinylpyrrolidone in the vinylpyrrolidone copolymer is not particularly limited, but is preferably 0.1 mol% or more, more preferably 5 mol% or more, and further preferably 20 mol% or more with respect to all monomer components. . When the proportion of vinylpyrrolidone in the copolymer is less than 0.1 mol%, the emulsifying action of the PVP composition cannot be obtained.

  The PVP used in the present invention preferably has a K value of 80 or more, and the effect of suppressing the decrease in the K value of the present invention is particularly remarkable for PVP having a K value of 80 or more, that is, PVP having a large molecular weight. This is because that. In addition, K value is a value calculated | required by following Formula (1) showing the magnitude | size of the molecular weight proposed by the fixture.

K value = ^{[{300ClogZ + (C + 1.5ClogZ)} 2} 1/2 + 1.5ClogZ-C ] ^{/ (0.15C + 0.003C 2) ......} (1)
Here, C is a concentration (%: g / 100 ml), and Z is a relative viscosity (ηrel) of a solution having a concentration C.

  The PVP composition of the present invention contains one or more compounds selected from the group consisting of guanidines, thereby stabilizing PVP and improving the storage stability of the PVP composition.

  Examples of the guanidines include guanidine, guanidine hydrochloride, guanidine nitrate, guanidine carbonate, guanidine phosphate, guanidine sulfamate and the like; aminoguanidine, aminoguanidine hydrochloride, aminoguanidine salt such as aminoguanidine bicarbonate, and the like. Is mentioned.

  Content of the said guanidine is 1-10000 ppm of PVP. Preferably it is 5-4000 ppm. If the content is less than 1 ppm, the effect of stabilization cannot be obtained and the storage stability is lowered. Even if the content exceeds 10,000 ppm, no further effect is obtained, and conversely, impurities are produced. These guanidines may be used alone or in combination of two or more.

  In the PVP composition of the present invention, 2-pyrrolidone and ammonia are contained in addition to the guanidines described above, whereby the decrease in K value of PVP due to shear stress, that is, the decrease in molecular weight can be suppressed.

  In the present invention, the content of 2-pyrrolidone relative to the PVP is 1000 to 30000 ppm. If the content is less than 1000 ppm, the effect of maintaining the K value against the shearing stress cannot be obtained, and if it exceeds 30000 ppm, impurities are produced. 2-Pyrrolidone may be added or a by-product after polymerization may be used.

  The content of ammonia with respect to the PVP is 1 to 5000 ppm. Preferably it is 1-1000 ppm. If the content is less than 1 ppm, a sufficient effect of suppressing a decrease in the K value will not be obtained, and if it exceeds 5000 ppm, it becomes an impurity and adversely affects the properties of the PVP composition.

  In addition, when the composition is a solid, the PVP composition of the present invention is preferably present in a space where the oxygen concentration in the gas phase is 5% or less, thereby suppressing a decrease in the K value of the PVP composition. Can do.

  That is, a PVP composition containing one or more guanidines in solid PVP and further containing 2-pyrrolidone and ammonia, and present in a space where the oxygen concentration in the gas phase of this composition is 5% or less It is important to do.

  The lower limit of the oxygen concentration in the gas phase is not particularly limited, and an effect can be exhibited even at a low concentration. However, if it exceeds 5%, the effect of suppressing a decrease in K value due to shear stress tends to decrease. become.

  In this case, the content of guanidine, 2-pyrrolidone and ammonia is not particularly limited, but it is preferable not to exceed the range of the content of each compound described above. That is, the content of guanidines is 1 to 10000 ppm with respect to PVP, the content of 2-pyrrolidone is 1000 to 30000 ppm, and the content of ammonia is preferably 1 to 5000 ppm, particularly the respective contents. If the upper limit is exceeded, it becomes an impurity and adversely affects the properties of the PVP composition.

  Here, the gas phase is a portion other than the solid phase part and / or the liquid phase part occupied by the composition in the space where the PVP composition exists, and the oxygen concentration in the gas phase is the unit volume of the gas phase. It means the absolute amount of oxygen in it. For example, when the PVP composition is housed in a sealed container, the oxygen concentration in the gas phase is the ratio of the volume occupied by the oxygen in the gas phase in the container at normal pressure to the volume of the gas phase. The oxygen concentration can be easily measured with a commercially available oxygen concentration meter such as a galvanic cell diffusion type or a zirconia sensor type.

  In order for the PVP composition to be present in a space where the oxygen concentration in the gas phase is 5% or less, the sealed container filled with an inert gas and containing the composition in a vacuum sealed container It can be accommodated in a sealed container in which an oxygen scavenger is enclosed.

  Examples of the present invention and comparative examples will be described below, but the present invention is not limited to these examples.

  Using PVP having different K values, according to the contents shown in Table 1, PVP compositions of Examples and Comparative Examples in which guanidine carbonate, 2-pyrrolidone and ammonia were added to PVP were prepared, and the solution PVP composition Was subjected to a high-speed stirring test, and the solid (flake) PVP composition was subjected to a pulverization test under severe conditions, and K values before and after the test were measured to evaluate changes in molecular weight. The test method is as follows.

  Here, the solution-like PVP used in the high-speed stirring test was prepared by adding various additives as a 30% aqueous solution and mixing them. The solid (flakes) PVP used in the pulverization test was prepared by adding various additives in a 30% aqueous solution state, mixing them, and drying on a hot plate at 140 ° C. so that the water content was 5% or less. The ammonia content of the dried product was measured by ion chromatography.

[Agitation and grinding test method]
High-speed stirring test: High-speed emulsification / dispersing machine (TK homomixer, manufactured by MARKII fmodel special machine industry Co., Ltd.) is used to perform high-speed stirring at 12,000 rpm for 20 minutes, and K values before and after that are measured. did.

  Crushing test: K values before and after sealing with a small crusher (mill) (SM-1 manufactured by ASONE Co., Ltd.) after crushing for 14,000 rpm × 15 minutes and replacing with nitrogen were measured.

  The measurement of the K value is a value calculated by fitting the relative viscosity measured by a capillary viscometer at 25 ° C. using a 1% aqueous solution of the PVP composition to the above Fikencher's equation (1).

  A decrease in K value of 1 or less was evaluated as acceptable with a small change in molecular weight, “◯”, and those of 2 or more were evaluated as rejected, and indicated with “x”.

  As shown in Table 1, the PVP composition of Example 1 according to the present invention can maintain the molecular weight without a decrease in K value even by high-speed stirring. In Example 2, the oxygen concentration in the gas phase is 4%, and a slight decrease in K value is observed due to pulverization under severe conditions. However, if the oxygen concentration is within 5%, the acceptable level can be maintained. On the other hand, in Comparative Example 1 that does not contain ammonia, and in Comparative Example 2 in which the oxygen concentration in the gas phase is too high, the decrease in K value due to shear stress is large.

The vinylpyrrolidone-based polymer composition of the present invention is useful as an emulsifier and binder for cosmetics and pharmaceuticals, for example.

Claims (1)

The vinyl pyrrolidone polymer having a K value of 80 or more contains 1 to 10,000 ppm of one or more compounds selected from the group consisting of guanidines, and further contains 1000 to 30000 ppm of 2-pyrrolidone and 1 to 5000 ppm of ammonia. A vinylpyrrolidone-based polymer composition characterized by comprising: