JPH10237126A - Ph-buffering and moisture-conditioning polymer, its production, and sheet or cosmetic containing the same polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject polymer having moisture-conditioning functions, well balanced in moisture absorption, retention and release and pH-buffering properties, by providing a specific polymer so as to have specified moisture absorption characteristics and specific moisture retention and release characteristics and further moderate pH-buffering actions in the polymer. SOLUTION: A polymer having ion exchangeable polar groups and a cross-linked structure is made to have moisture absorption characteristics at 15-100wt.% moisture absorption coefficient under 20 deg.C and 65% RH conditions and moisture retention and release characteristics of 15-80wt.% moisture absorption coefficient after allowing the polymer absorbing the moisture to saturation under conditions of 20 deg.C and 80% RH to stand under conditions of 20 deg.C and 40% RH for 1hr and buffing actions at pH4-10. Sulfonate groups, carboxyl groups, phosphate groups, etc., are preferred as the ion exchangeable polar groups. For example, an amine structure obtained by reacting nitrile groups in a high-nitrile-based polymer containing >=50wt.% nitrile group-containing vinyl monomer with a hydrazine-based compound is cited as the cross-linked structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polymer having pH buffering and humidity control properties, a method for producing the same, and a sheet or cosmetic containing the polymer. More specifically, the polymer has a moisture control function in which moisture absorption, moisture retention and moisture release are well-balanced, and the polymer has a pH buffering action, and the pH range obtained by this buffering action is between 4 and 10. The present invention relates to a pH buffering / humidity-controlling polymer and a method for producing the same, and also relates to a sheet or a cosmetic such as paper, nonwoven fabric, foamed sheet or the like containing the polymer.

[0002]

2. Description of the Related Art Under normal conditions, human skin is kept weakly acidic due to secreted lactic acid and the like, but the pH of the skin is reduced due to acid rain accompanying the recent environmental destruction and alkalinization of clothes due to washing. Beyond the normal range, this undermines healthy skin. In order to keep the pH of the skin weakly acidic, it is desirable that the material that comes into contact with the skin itself is weakly acidic, while the acid or alkali from the outside is neutralized by clothing.
As a method for responding to such a demand, a method in which a protein having a weakly acidic isoelectric point is attached to a fiber product by post-processing, a method in which the fiber itself has a pH buffering action (Japanese Patent Application Laid-Open No. 7-216730), and the like Has been proposed. But,
These methods have a drawback that their effects are not sufficient because they are indirect methods rather than acting directly on the skin, or they are effective only when wearing such clothes.

Further, the above-mentioned fibrous material has the following problems. 1. The first major problem is that since it is fibrous, it is difficult to uniformly disperse it into lumps when added to resin, cream, etc. Can not.
2. It is necessary to maintain the physical properties of the fiber enough to withstand post-processing and to withstand use when it is made into a product, and therefore, the ability to exhibit a pH buffering / humidifying function may be sacrificed. For example, in the case where the polymer skeleton of the fiber itself is chemically modified to impart pH buffering and humidity control properties, it is necessary to maintain fiber properties at a certain level or higher. It is used for the purpose, and as a result, the pH buffering / humidifying function developing ability is reduced, or
In the case where a protein or the like having a pH buffering / humidifying function is kneaded in the fiber, the amount of the protein that can be kneaded into the fiber is limited in order to maintain fiber physical properties. There is a problem that it cannot be sufficiently expressed. 3. Generally, in the case of fibers obtained industrially, the fiber diameter is about 10 μ or more, so that the surface area per unit weight is small. There is a problem that a sufficient function is hardly exhibited.

For example, in the case of Japanese Patent Application Laid-Open No. Hei 7-216730,
Since it is necessary to maintain properties such as physical properties and color required for fibers, a considerable amount of nitrile groups in acrylic fibers are used for crosslinking. In this case, pH buffer
As a polar group (a carboxyl group in the case of the patent) expressing a humidity control function, the nitrile group deducted by the amount of the nitrile used for crosslinking in the acrylic fiber is chemically modified, and as a result, The amount of carboxyl groups is low and limited, and the desired function may not be sufficiently satisfied. In addition, in the patent, amide groups not directly related to the pH buffering / humidifying function are described as essential constituents due to the reaction conditions or the physical properties of the fibers, and the functions obtained per unit weight are inefficient. ing. For these reasons, it is disadvantageous in terms of cost.

On the other hand, when attention is paid to humidity control, the stratum corneum, which is the outermost layer of the skin, tends to dry under weather conditions such as low temperature and low humidity in winter, so that the skin becomes bulky or rough. Also, excessive use of detergents and solvents can leave the skin bulky and rough. Such roughening and roughening of the skin is caused by the loss of a water-absorbing water-soluble component called NMF (natural moisturizing factor) in the stratum corneum, the reduction of moisture in the stratum corneum, and the softening of the stratum corneum. It is thought to be caused by loss of sex.

[0006] For this reason, conventionally, in cosmetics intended to soften the skin, a large amount of water is given to the stratum corneum,
In addition, various moisturizing components are blended in order to keep the applied moisture for a long time. In particular, since the NMF component contains an organic acid (carboxylic acid), amino acid, urea, etc., various organic acids, amino acids or urea are blended into the cosmetic to replenish the lost NMF component to the skin. That is being done.

For example, as a compound containing an organic acid as one of the NMF components, a compound utilizing the softening action of the stratum corneum of α-oxyacid has been proposed (JP-A-55-19).
291). However, the resulting softening effect is transient and not permanent. Further, there is a disadvantage that the pH at which the α-oxyacid exerts the softening action of the stratum corneum is in a low range (pH 2 to 4) where normal skin physiology is inhibited.

On the other hand, there has been reported an example in which an alkali such as sodium hydroxide, potassium hydroxide or triethanolamine is added to an α-oxyacid solution in order to utilize the α-oxyacid in a neutral pH range. I have. However, if a large amount of alkali is added, the stability of the solution is reduced, and it is difficult to maintain the cosmetic at a stable quality. In addition, since the originally preferred pH of the skin is weakly acidic such as about 4 to 6, the use of a large amount of alkali is harmful to the skin. Furthermore, it has been reported that prolonged continuous use of amines causes an allergic reaction.

Further, it has been proposed to mix succinic acid or a salt thereof as an NMF component organic acid in cosmetics together with urea and amino acids (Japanese Patent Application Laid-Open No. 5-163129). Furthermore, as an example of using an amino acid or a derivative thereof as one of the NMF components, it has been reported that a protein degradation product such as yoquinin or a certain peptide has a moisturizing effect and a softening effect (Japanese Unexamined Patent Application, First Publication No. H11-163873). Showa 6
2-99315, JP-A-2-178207).

[0010] In addition, as a humectant or softener,
In addition to the NMF-related components as described above, water-soluble polyhydric alcohols, especially propylene glycol and a molecular weight of 200 to 40
About 0 polyethylene glycol is widely used. In addition, since betaine has an effect of increasing the turnover speed of the stratum corneum and preventing skin roughness, it has been proposed to incorporate it into cosmetics (Japanese Patent Laid-Open No. 1-2755).
No. 11).

However, conventional NMFs such as the above-mentioned organic acids such as α-oxy, amino acids and derivatives thereof, etc.
The related components have a sticky feeling, and therefore, there has been a problem that a cosmetic composition containing them cannot provide a satisfactory feeling of use. Further, in order to obtain a sufficient moisturizing effect, a large amount of water-soluble polyhydric alcohols such as propylene glycol and polyethylene glycol must be incorporated in the cosmetic in a large amount, in which case there is a problem that a sticky feeling is generated. . Further, there was a concern about the use of a large amount in terms of safety (allergy). On the other hand, with regard to betaine, cosmetics containing it have an excellent moisturizing effect, but it has been desired to improve moistness, smoothness or smoothness in use.

[0012] As another application, a filter having a humidity control function such as moisture absorption, moisture retention and moisture release is required.
In view of the above, there has been proposed a fibrous material corresponding to those described above. However, in the case of a fibrous form, the above-mentioned problems occur for maintaining the fiber form, and the function is insufficient, or the function is blocked by a binder or the like at the time of molding into a filter due to a small unit surface area. However, there is a problem in that the function of cannot be sufficiently performed.

[0013]

SUMMARY OF THE INVENTION The present invention is to solve the problems of the prior art as described above,
Humidity control / humidifying function with balanced moisture retention and moderate pH
PH-buffer / humidity-controlling polymer having a buffering action, a method for producing the polymer, and a sheet or a sheet containing the polymer, which improve both moisturizing effect and moist feeling, smooth feeling, or smoothness of use. It is another object of the present invention to provide cosmetics with improved durability.

[0014]

Means for Solving the Problems The present inventor has proposed a pH buffer /
We have been conducting intensive research on humidity control polymers. As a result, in a polymer having an ion-exchange polar group and a cross-linked structure, the polymer has a specific moisture absorption property and a moisture retention / release property, and the pH range obtained by the buffer action of the polymer is 4 to 10. The present inventors have found that the present object can be achieved by an intervening pH buffering / humidity controlling polymer, and have completed the present invention. That is, the present invention provides a polymer having an ion-exchangeable polar group and a crosslinked structure, as a moisture absorbing property at 20 ° C.
Moisture absorption under 65% RH condition is 15% by weight or more and 100% by weight or less.
The polymer, which was saturated and absorbed under RH conditions, was heated at 20 ° C. and 40% R
The moisture absorption after leaving for 1 hour under H condition is 15% by weight or more and 80% or more.
A pH range of from 4 to 10 having a moisture control function of not more than 1% by weight and having a well-balanced moisture-absorbing, moisture-retaining and moisture-releasing function, and a pH range obtained by a buffering action of the polymer.
A buffer / humidity-controlling polymer, a method for producing the same, and a sheet or cosmetic containing the polymer.
Hereinafter, the present invention will be described in detail.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION First, the polymer of the present invention has a moisture absorption rate of 15% by weight or more and 100% by weight or less under conditions of 20 ° C. and 65% RH. Moisture absorption, moisture retention / moisture release after the polymer which has been saturated and absorbed at 20 ° C. and 80% RH for 1 hour at 20 ° C. and 80% RH. Has a well-balanced humidity control function, and the pH range obtained by the buffer action of the polymer is 4-1.
Must be between 0.

Here, the moisture absorption defined in the present invention means the moisture absorption obtained by the following method. That is, about 5.
0 g is dried with a hot air dryer at 105 ° C. for 16 hours, and the weight is measured (W1) g. Then, the sample is thermostatically adjusted to a specific temperature and humidity condition (for example, a temperature of 20 ° C. and a relative humidity of 65% RH). The sample was placed in a constant humidity machine for 24 hours, and the weight of the sample that absorbed moisture was measured (W2) g. From the above results, it was calculated by the following equation. Moisture absorption (% by weight) = {(W2−W1) / W1} × 100 As the moisture retention / desorption characteristics, the polymer which has been saturated and absorbed at 20 ° C. and 80% RH is subjected to 20 ° C. and 40% RH. It is defined as the moisture absorption after leaving for 1 hour under the conditions.

The pH range obtained by the buffering action is defined as a sample obtained by drying a sample at 105 ° C. for 16 hours using a hot air drier.
0 g was added to 100 g of an aqueous solution having a pH of 2 with hydrochloric acid, and after stirring at room temperature for 1 hour, the pH was adjusted to an acidic pH, and the same sample was added to 100 g of an aqueous solution having a pH of 12 with sodium hydroxide. Then, the pH after stirring at room temperature for 1 hour was taken as the pH on the alkali side, and the pH on the alkali side was expressed in the range from the pH on the acidic side.

When the moisture absorption under a condition of 20 ° C. and 65% RH is less than 15% by weight, the moisture absorption is too low to obtain a sufficient effect. If the moisture absorption exceeds 100% by weight under the same conditions, the swelling of the particles becomes too large, making it difficult to use as an additive, and the swelling obstructs the gas passage, resulting in a low moisture absorption rate. The problem comes out. In addition, there is a problem that stickiness appears, which is not preferable. As a moisturizing / releasing property, a polymer saturated and absorbed under conditions of 20 ° C. and 80% RH is used.
The moisture absorption after leaving for 1 hour at 40 ° C. and 40% RH is 1
If the content is less than 5% by weight, the moisture release rate is too high, so that sufficient moisture retention cannot be maintained. When the moisture absorption rate after standing under the same conditions exceeds 80% by weight, the moisture absorption characteristics described as 10% were described.
The same problem as that in the case of exceeding 0% by weight occurs. In particular, this problem becomes remarkable at the time of moisture absorption, that is, at 20 ° C. and 80% RH.

When the pH range obtained by the buffering action is less than 4, a sufficient effect cannot be obtained with a small amount of addition, that is, weak acidity cannot be obtained. Alternatively, when the region exceeds 10, a sufficient effect cannot be obtained similarly,
There is a problem that the pH cannot be efficiently stabilized near neutrality.

The ion-exchangeable polar group referred to in the present invention is:
There is no particular limitation as long as it is a polar group capable of ion-exchanging an anion or cation ion. For example, a primary amino group, a secondary amino group, a tertiary amino group, a quaternary amino group,
Phosphate group, phosphate group, hydroxyl group, mercapto group,
Examples thereof include a carboxyl group, a sulfonic group, a sulfonyl group, and a sulfate group. In particular, when a sulfonic acid group, a carboxyl group, or a phosphate group that easily forms a complex or a salt with a metal ion is used, a polymer having excellent pH buffering and humidity control properties can be obtained, and good results can be obtained.

The amount of the above-mentioned polar group contained in the polymer of the present invention is not particularly limited and may be appropriately selected as long as the pH buffer and humidity control required according to the application actually used can be exhibited. can do. However, from the viewpoint of enhancing the pH buffering / humidity control function, it is preferable that the amount of the polar group contained is large, and in practice, it is at least 0.1 milliequivalent /
g or more of a polar group is preferable, and the function can be exhibited by adding a small amount of an additive, so that a particularly good result can be obtained more preferably at 2.0 meq / g or more.

The method of introducing the polar group into the polymer particles is not particularly limited, either. The introduction of the polar group-containing monomer by using the polymer at the stage of polymerizing the skeletal polymer, or the chemical, A method such as introduction of a polar group by physical modification can be used. However, since it is necessary to contain a polar group in a large amount as much as possible, adding a large amount of a monomer having a polar group in the polymerization step has a problem that the stability is lowered in both aqueous and non-aqueous polymerization. . Therefore, better results can be obtained by introducing a polar group by performing a chemical or physical reaction after forming polymer particles by polymerization.

The counter ion of the above-mentioned ion-exchangeable polar group is not particularly limited, and can be appropriately selected depending on its use. Specifically, among the above, as the counter ion of the acidic group, not only a hydrogen ion, but also an alkali metal Be, Mg, such as Li, Na, and K, as well as a hydrogen ion,
Alkaline earth metals such as Ca and Ba, Cu, Zn, Al,
Other metals such as Mn, Ag, Fe, Co, Ni, NH4,
Organic cations such as amines can be mentioned. In addition, examples of the basic group include a hydroxyl group, chlorine, fluorine, and bromine. It is needless to say that two or more counter ions may be mixed.

In particular, when any one of Ca, Mg, Na, K, Li, and Al is contained as a hydrogen ion and a metal ion, it is easy to balance acid and alkali, so that excellent pH buffering property is obtained. Results can be obtained. In this case, the equivalence ratio between the hydrogen ion and the metal ion is not particularly limited, but the ratio of the ion is set to 1.
Better results can be obtained by setting the range of 0: 1.5 to 4.0: 1.0. When the ratio of hydrogen ions is higher than 4.0 to 1.0,
Although the buffering property for alkaline substances is large, the buffering property for acidic substances is not sufficient. On the other hand, when the ratio of metal ions is higher than 1.0 to 1.5, the buffering property for an acidic substance tends to be insufficient, whereas the buffering property for an alkaline substance is insufficient.

As described above, the method for adjusting the equivalent ratio containing hydrogen ions and metal ions can be appropriately selected and is not particularly limited. However, the following method is advantageous in terms of process and cost. That is, when hydrolysis with an acid is performed, Ca, Mg, Na,
A method of adding at least one hydroxide selected from K, Li, and Al, adjusting the pH to 5.0 to 7.0, and then washing with water and drying. When hydrolysis with an alkali is performed, acid treatment is performed once, and the total amount of acidic ion exchange groups such as a carboxyl group is converted to a hydrogen ion form.
g, Na, K, Li, Al nitrate, hydrochloride, sulfate,
In this method, one or more metal salts selected from phosphates are added to adjust the pH to 5.0 to 7.0, followed by washing with water and drying.

The polymer of the present invention is not particularly limited as long as it has an ion-exchangeable polar group and a crosslinked structure, and may be any of a natural polymer, a semi-synthetic polymer and a synthetic polymer. Specific polymers include, for example, polyethylene, polypropylene, vinyl chloride, ABS resin, nylon, polyester, polyvinylidene chloride, polyamide, polystyrene, polyacetal, polycarbonate, acrylic resin, fluororesin, polyurethane elastomer, polyester elastomer,
Plastic polymers such as melamine resin, urea resin, tetrafluoroethylene resin, unsaturated polyester resin, epoxy resin, urethane resin and phenol resin; nylon, polyethylene, rayon, acetate, acrylic,
General fiber-forming polymers such as polyvinyl alcohol, polypropylene, cupra, triacetate, and vinylidene; natural rubber and silicone rubber, SBR (styrene-butadiene rubber), CR (chloroprene rubber), E
PM (ethylene / propylene rubber) FPM (fluoro rubber), NBR (nitrile rubber), CSM (chlorosulfonated polyethylene rubber), BR (butadiene rubber), I
Synthetic rubber polymers such as R (synthetic natural rubber), IIR (butyl rubber), urethane rubber and acrylic rubber.

Among them, a basic skeleton based on a carbon-carbon bond is considered to have a property capable of withstanding physical and chemical changes accompanying the introduction of a polar group or the ion exchange of the group, ie, heat resistance and chemical resistance. Polymers having, for example, vinyl polymers are preferable, and polymers into which an ion-exchangeable polar group can be easily introduced, specifically, polystyrene, polyacrylonitrile, polyacrylester, and polymethacrylester. Good results can be obtained by using the above polymer.

The crosslinked structure contained in the basic skeleton polymer is not particularly limited as long as the polymer is not physically or chemically modified in the step of introducing an ion-exchange or ion-exchange polar group. However, any structure such as cross-linking by covalent bond, ionic cross-linking, cross-linking by polymer molecule interaction or crystal structure may be used.
In addition, the method for introducing cross-linking is not particularly limited, and a generally used method such as cross-linking with a cross-linking agent at the polymerization stage of the skeletal polymer, post-cross-linking after polymerization, introduction of a cross-linking structure by physical energy, and the like. be able to. Among them, those introduced with a cross-linking agent of divinylbenzene or triallyl isocyanurate are preferable because a cross-linking structure that is easily, thermally and chemically stable can be introduced into the vinyl polymer. In addition to this, the nitrile group contained in the high-nitrile polymer having a nitrile group-containing vinyl monomer content of 50% by weight or more has the advantage that the post-crosslinking can maintain the form because it can be post-crosslinked. A method using a post-crosslinking method comprising a structure obtained by reaction with a compound or formaldehyde, among which a method using a hydrazine compound, can obtain excellent results as described later.

The above-mentioned high nitrile-based polymer means a polymer having a high nitrile group content, and specifically refers to a polymer having a nitrile group-containing vinyl monomer content of 50% by weight or more. The vinyl monomer having a nitrile group, which is a raw material of the high nitrile polymer, is not particularly limited as long as it has a nitrile group.Specifically, acrylonitrile, methacrylonitrile, ethacrylonitrile,
α-chloroacrylonitrile, α-fluoroacrylonitrile, vinylidene cyanide and the like. Among them, acrylonitrile, which is advantageous in terms of cost and has a large amount of nitrile group per unit weight, is preferable.

The nitrile group in the above-mentioned high nitrile polymer and the amine structure introduced by treatment with the hydrazine compound specifically include an amino group (primary-NH2, secondary-NHR, Tertiary-NRR ′), basic groups such as imino group, hydrazino group, hydrazono group, hydrazo group, diazoamino group, ureido group, ureylene group, guanidino group, hydrazinocarbonyl group, amidino group, carbamoyl group and the like. Has a mixture of these structures, and a part thereof contributes to crosslinking. The amine structure may be a chain or a cyclic (triazole ring, tetrazine ring, etc.). The content of these amine structures can be expressed as the sum of the exchange capacities (milliequivalents / g) of the above-mentioned basic groups such as amino groups and imino groups.

The treatment for introducing the amine structure is not particularly limited as long as a crosslinked structure is obtained, and the treatment according to the intended use, that is, the reaction conditions can be appropriately selected. For example, the reaction state of the high nitrile-based polymer and the hydrazine-based compound may be a molten state having a melting point or higher, a state in which the reactant is dissolved in an organic or inorganic solvent, or a reaction between an organic solvent and water. The state of being dispersed in the medium can be appropriately selected. At this time, the concentrations of the high nitrile polymer and the hydrazine compound in a reaction such as dilution with a solvent or dispersion in a solvent can be appropriately selected in the reaction. In addition, the reaction temperature is not particularly limited, and a reaction temperature according to each of the above-described reaction states can be appropriately set. However, when the reaction temperature is too low, the reaction rate becomes slow and the reaction time becomes too long. Therefore, when the reaction is carried out at a temperature of 50 ° C. or more, more preferably 80 ° C. to 150 ° C., a favorable result is often obtained. Further, the site where the high nitrile-based polymer is reacted with the hydrazine-based compound is not particularly limited, and can be appropriately selected depending on the use and the form of the polymer. Specifically, it can be appropriately selected to react only on the surface of the high nitrile-based polymer, or to react to the core over the whole, or to react by limiting a specific site. The hydrazine compounds used herein include hydrazine salts such as hydrazine hydrate, hydrazine sulfate, hydrazine hydrochloride, hydrazine nitrate, hydrazine bromate, and hydrazine carbonate; and ethylenediamine, guanidine sulfate, guanidine hydrochloride, guanidine nitrate, and phosphorus. And hydrazine derivatives such as guanidine acid and melamine.

Here, in the case where the polymer of the present invention is an acrylonitrile-based polymer cross-linked with a hydrazine-based compound, a derivative in which 0.1% by weight or more of the remaining nitrile groups is converted to a carboxyl group is as follows. It is preferable in such a point. That is, there is an advantage that by having amphoteric properties of an anion and a cation, a function similar to that of betaine as described above can be imparted, and ions can be more efficiently exchanged into a polymer. In this case, one in which all of the remaining nitrile groups are finally converted to carboxyl groups is the case where the amount of carboxyl groups as ion exchange groups is the largest, and gives particularly favorable results in the function expression as described above. is there.

In the case of a high nitrile polymer, there is no particular limitation on the form thereof, and an appropriate one such as a particle, a resin molded article, or a foamed article can be employed. The composition of the polymer is not particularly limited as long as the content of the vinyl monomer having a nitrile group is 50% by weight or more, and the vinyl monomer having a nitrile group alone or the monomer content of 50% by weight is used. % Or more as long as the polymer is at least one other ethylenically unsaturated compound. As the other ethylenically unsaturated compound referred to herein, specifically, a known unsaturated compound copolymerizable with the above-mentioned vinyl monomer having a nitrile group, for example, vinyl chloride, vinyl bromide, vinyl fluoride, chloride Vinyl halides such as vinylidene and vinylidene halides; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid and salts thereof; methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate; Acrylic esters such as methoxyethyl acrylate, phenyl acrylate, cyclohexyl acrylate; methacrylic esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate; methyl vinyl Unsaturated ketones such as ton, phenyl vinyl ketone, methyl isobutenyl ketone and methyl isopropenyl ketone; vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate and vinyl benzoate; methyl vinyl ether, ethyl vinyl ether Acrylamide and its alkyl-substituted products; unsaturated sulfonic acids such as vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid and salts thereof; styrene,
Styrene such as methylstyrene, chlorostyrene and the like or alkyl- or halogen-substituted products thereof; allyl alcohol and esters or ethers thereof; vinylpyridine;
Basic vinyl compounds such as vinylimidazole and dimethylaminoethyl methacrylate; unsaturated aldehydes such as acrolein and methacrylolein; glycidyl methacrylate, N-methylolacrylamide, hydroxyethyl methacrylate, triallyl isocyanurate, divinylbenzene, ethylene glycol di (meth) ) Crosslinkable vinyl compounds such as acrylate and methylenebisacrylamide.

The method of treating a high nitrile polymer with a hydrazine compound to introduce an amine structure into the polymer and to form a post-crosslinking polymer is not particularly limited. In aqueous solution at a temperature of 50-1
Means of treating at 40 ° C. for 1 to 15 hours give industrially favorable results.

In the hydrazine treatment, a crosslinked structure having an amine structure is formed by reacting a nitrile group of a raw material high nitrile polymer with an amine of a hydrazine compound;
It is considered that the introduction of the same amine structure derived from the hydrazine-based compound is performed. In addition, it is considered that one part of a carboxyl group is also generated by hydrolysis of the nitrile group.

At the time of treatment with this hydrazine compound,
When the hydrazine compound ionically bonded to the carboxyl group generated by the hydrolysis of the nitrile group is released and poses a problem, an acid treatment for removing this may be performed. As the method, a method in which the above-mentioned hydrazine-based compound-treated polymer is immersed in various acidic aqueous solutions, for example, hydrochloric acid, acetic acid, nitric acid, sulfuric acid and the like, and then dried is suitably used. However, in the sense of imparting a pH buffering property, if the acid treatment is excessively performed, the pH buffering performance is reduced. Therefore, in order to restore the ability reduced by the acid treatment, the pH adjusted and ionized amine is used. It is desirable to make a part of the structure neutral. In this case, there is a means for adjusting the pH to a desired value while immersing the polymer in a basic aqueous solution of an alkali metal hydroxide, ammonia or the like, and then drying the polymer.

The form of the pH-buffer / humidity-controlling polymer in the present invention is not particularly limited, and can be appropriately selected according to the practical use. Specifically, three-dimensional blocks,
That is, it is a plastic, a resin molded product, a plastic foam, a planar film, a coating film, paper, a nonwoven fabric, a sheet-like plastic foam, a particulate powder, or the like. In particular, in the case of a particulate powder, since it can be used as an additive in each of the above-described forms, its application range is wide and useful. Further, in the case of particulate powder, the surface area per unit weight is larger than in other forms, so that the pH buffering / humidification rate is increased. In addition, even if the exchange capacity of the ion-exchange polar groups contributing to pH buffering and humidity control is the same, the polar groups are often located near the surface, so that the exchange capacity can be effectively used. There is a merit that you can do it.

When the pH-buffer / humidity-controlling polymer is a particulate powder, its shape is not particularly limited, and may be spherical, needle-like, spindle-like, rod-like, cylindrical, polyhedral, multi-needle-like,
It can take any shape such as a plate, a scale, an irregular shape, or an aggregated state of each of those shapes. In addition, the size of these particles can be appropriately selected according to the application, and is not particularly limited, but when the average particle size is 1000 μm or less, more preferably 100 μm or less fine particles. In this case, the surface area is increased, and the pH buffering / humidifying performance is improved, and good results can be obtained. Good results are also obtained when the polymer is in the form of agglomerated particles, especially when the average particle size of the primary particles is 5%.
When the average particle diameter of the aggregate is 100 μm or less, an appropriate cavity is formed in the gap between the primary particles and the surface area per unit weight is increased, so that excellent results are obtained. be able to.

Among the usage forms of the polymer obtained by the present invention, particularly when used as paper, nonwoven fabric or foamed sheet, the polymer has a large contact area with gas and is excellent in shape retention, so that it can be controlled. Useful as a wet material.
The method of forming the paper, nonwoven fabric or foam sheet is not particularly limited as long as the pH buffering / humidity controlling polymer of the present invention is used, and specifically, the form is formed by the fibrous polymer. Or a method supporting the particulate polymer. However, better results can be obtained in the case of supporting a particulate pH buffer / humidity-controlling polymer because of its low cost or large surface area per unit weight and high pH buffering / humidifying efficiency. Can be.

The loading method is not particularly limited, such as being mixed, impregnated or included in the matrix constituting the material, and various methods can be adopted. Also, p
The H-buffer / humidity-controlling polymer particles may be present inside the matrix, or may be present on the matrix surface.For example, paper, nonwoven fabric, a method of mixing the polymer particles in the process of producing a foamed sheet, or Any method such as a method of impregnating these with a slurry of the polymer particles can be adopted.

As a specific example, when paper is manufactured by papermaking technology using pH-buffered, moisture-controlling polymer particles as a filler, a slurry of a papermaking material such as pulp or synthetic fiber dispersed in a large amount of water is used. After the addition of the polymer particles and other additives, the mixture is thoroughly mixed and can be produced using a usual paper machine. At this time, if necessary, a fixing agent can be added in order to suppress the loss of the filler. Examples of the fixing agent include modified polyethyleneimine, modified polyacrylamide, sodium alginate, gum arabic, and positive starch. , Aluminum sulphate, potash and the like. The amount of the fixing agent can be appropriately selected depending on the type and the amount of the polymer particles used. Further, a sizing agent, a dye, a paper strength enhancer and the like generally used in a paper making process can also be appropriately used. Further, as the surfactant, anionic,
It can be appropriately selected and used from a cationic type or a nonionic type in consideration of other additives and the like. The pH-buffer / humidity-controlling polymer particles used in the papermaking are not particularly limited, but a preferable result is obtained when powder having a particle diameter of 1 to 100 μm is used. If the particle diameter is smaller than 1 μm, it may fall along with water from the net of the paper machine at the time of papermaking, while if it exceeds 100 μm, a problem may occur that the particle size is too large and it is difficult to disperse uniformly. .

In the case of forming as a non-woven fabric,
There is no particular limitation, and the present invention can be applied to nonwoven fabrics produced by various production methods. Specifically, in the dry method, an adhesive type dipping method, a printing method, a spray method, a powder method, an adhesive fiber method (thermal bonding method), a mechanical bonding type felt method,
In the stitch method, the needle punch method, the hydroentangled spunlace method, the spinning type spunbond method, the mesh method, the melt blow method, the film method, and the wet method, the hydroentangled spunlace method and the spinning spunbond method Method, flash spinning method, paper-making type heat fusion fiber method, hot pressure method, adhesive method and the like. There is no particular limitation on the method of supporting the pH buffering / humidity-controlling polymer. For example, the pH buffering / humidity-controlling polymer is supported by various methods such as being sandwiched between these nonwoven fabrics, adhered and supported on a fiber material constituting the nonwoven fabric, or applied to the surface of the nonwoven fabric. be able to. The basis weight of these nonwoven fabrics is not particularly limited, but those having a basis weight of 20 to 300 g / m2 often give good results, and a basis weight of 20 g / m2.
If it is less than the strength, the strength is low, and it is likely to cause blurring. On the other hand, if it exceeds 300 g / m2, the gas-liquid permeability tends to be low, which may be undesirable. In particular, as a preferable nonwoven fabric, a spunbonded nonwoven fabric formed using a composite fiber comprising a sheath component made of polyethylene and a core component made of polypropylene or polyester, or a polyester fiber web layer on the front surface and a polypropylene web layer on the back surface. Nonwoven fabrics having a certain two-layer structure can be cited, and these nonwoven fabrics can be obtained from preferable materials because they can be easily processed from polyolefin components having a low melting point. When a plastic foam is used as a matrix, the polymer particles are mixed with a plastic foam, for example, foamed polyurethane or the like by a usual method, or a method of impregnating with a slurry of pH buffering / humidity controlling polymer particles is used. The intended polymer-containing plastic foam can be obtained.

The pH-buffer / humidity-controlling polymer of the present invention has excellent pH-buffering property and humidity-controlling effect. Therefore, by using the polymer as a raw material for cosmetics, it has a moisturizing effect and a moisturizing effect. This makes it possible to provide a cosmetic composition that satisfies both the sensation, smoothness, and smoothness of use, and is excellent in the sustainability of the effect. The cosmetic in the present invention is not particularly limited as long as it contains the above-mentioned pH buffering / humidity controlling polymer of the present invention. Here, the content ratio of the polymer in the cosmetic is not particularly limited, but is usually 0.01 to 40% by weight. If the amount is less than 0.01% by weight, it is difficult to obtain a sufficient pH buffering / humidifying effect, and even if the amount exceeds 40% by weight, the effect according to the blending amount cannot be obtained in many cases.

If necessary, the cosmetic may further contain other humectants, thickeners, preservatives, surfactants, oils, antioxidants, chelating agents, ultraviolet absorbers, powders, pigments, active ingredients. , Fragrance, etal, purified water and the like can be contained within a range not to impair the effects of the present invention. The cosmetic is
There is no particular limitation on the dosage form, and it can be applied to lotions, emulsions, creams, packs, jewelry, foundations and the like. In addition, various phase modes such as a homogeneous solution system, an emulsion system, and a two-layer system can be adopted. In this case, the production method can be a conventional method.

[0045]

The reason why the pH-buffer / humidity-controlling polymer of the present invention and the excellent pH-buffer / humidity-controlling performance provided by the production method have not been sufficiently elucidated, but are generally as follows. Conceivable. That is, the polymer according to the present invention has a large amount of ion-exchange polar groups, and the polar groups have extremely high hydrophilicity and easily absorb moisture. Further, unlike the general free water, the absorbed water is hard to separate because it is firmly fixed to the polar group as bound water. As a result, it is considered that moisture retention and gentle moisture release are possible.
Further, regarding the pH buffering property, it is considered that a large amount of the above-mentioned ion-exchangeable polar groups balance acidic and basic properties.

[0046]

The present invention will be described in detail with reference to the following examples. The percentages and parts in the examples are given on a weight basis unless otherwise specified. First, each evaluation method and the definition of terms will be described.

The measurement of the moisture absorption of the polymer was performed by the method described above. The descriptions in the tables in the examples are as follows: 20 ° C., 65% R
The moisture absorption rate under the H condition represents the moisture absorption property, and S
The TD moisture absorption (standard condition moisture absorption) was described.
That is, it means that the larger the value is, the more excellent the moisture absorbing property is. In addition, as to what expresses the moisturizing / dehumidifying properties, it is described in the item of moisture absorption rate under dry conditions,
The moisture absorption at 0% RH and the sample adjusted to the conditions were 2
The moisture absorption after leaving at 0 ° C. and 40% RH for 1 hour is described.
In this case, it can be determined that the higher the moisture absorption rate of the latter and the greater the difference between the moisture absorption rates of the former and the latter, the better the moisture retention / desorption properties.

The measurement of the pH buffering ability was also performed by the method described above. The descriptions in the tables in the examples are as follows: low pH side (acidic side) and high pH side (alkaline side)
In the above, the obtained pH values were described as an acid-side pH buffer value and an alkali-side pH buffer value. From the viewpoint of pH buffering properties, the closer these values are to 7, the better the buffering action.

The average particle diameter of the particulate matter is expressed by volume based on the result of measurement using a laser diffraction particle size distribution analyzer “SALD2000” manufactured by Shimadzu Corporation with water as a dispersion medium, and the median diameter is used as the average particle diameter. Diameter.

The amount of the ion-exchangeable polar group obtained by the reaction was determined by acid-base titration, and the amount of the polar group was determined from the titration curve.

Example 1 Methacrylic acid / sodium p-styrenesulfonate = 70 /
30 parts of the water-soluble polymer 30 and 30 parts of sodium sulfate were dissolved in 6595 parts of water, and charged in a polymerization tank equipped with a paddle-type stirrer. Next, 2,2'-azobis- (2,4-) was added to 2700 parts of methyl acrylate and 300 parts of divinylbenzene.
Dimethyl valeronitrile) was dissolved in 15 parts, charged into a polymerization tank, and polymerized at 60 ° C. for 2 hours under stirring conditions of 400 rpm to obtain a methyl acrylate / divinylbenzene copolymer having a polymerization rate of 87% and an average particle diameter of 64 μm. Obtained. The polymer 10
0 parts were dispersed in 900 parts of water, and 100 parts of caustic soda was added thereto, reacted at 90 ° C. for 2 hours, and hydrolyzed the methyl ester part of methyl acrylate to obtain 4.5 meq of carboxyl groups. / G of crosslinked polymer was obtained. The obtained polymer is dispersed in water, and the pH is adjusted with nitric acid.
Was adjusted to 6.5, and calcium nitrate was added, and 60
The metal salt treatment was performed at 2 ° C. for 2 hours. And washing, dehydration,
After drying, fine particles of a pH-buffered and humidity-controlling polymer were obtained. Table 1 summarizes the characteristics of the fine particles. As you can see from the results,
It was confirmed that the polymer fine particles had excellent pH buffering properties and humidity control properties.

[0052]

[Table 1]

Example 2 Methacrylic acid / sodium p-styrenesulfonate = 70 /
30 parts of the water-soluble polymer 30 and 30 parts of sodium sulfate were dissolved in 6595 parts of water, and charged in a polymerization tank equipped with a paddle-type stirrer. Next, 15 parts of 2,2'-azobis- (2,4-dimethylvaleronitrile) were dissolved in 2700 parts of acrylonitrile (AN) and 300 parts of methyl acrylate, and the solution was charged into a polymerization tank and stirred at 400 ° C. at 60 ° C. For 2 hours to obtain a high nitrile polymer having a polymerization rate of 87% and an average particle diameter of 52 μm. 100 parts of the polymer was mixed with 50 parts by weight of 60% by weight hydrazine and 850 parts of water.
The crosslinking was introduced by performing hydrazine treatment at 3 ° C. for 3 hours, and 100 parts of caustic soda was further added,
By conducting the reaction at 120 ° C. for 2 hours, all of the residual nitrile groups were hydrolyzed to introduce carboxylic acid groups (at the end of the hydrolysis reaction, sodium form). The obtained polymer is dispersed in water, and the pH is adjusted to 6.5 with nitric acid. Then, calcium nitrate is added, the mixture is treated with a metal salt at 60 ° C. for 2 hours, washed, dehydrated, and dried to obtain a pH buffer and humidity control. Polymer fine particles were obtained. Table 1 summarizes the characteristics of the fine particles. As can be seen from the results, it was confirmed that the polymer fine particles had excellent pH buffering properties and humidity control properties.

Example 3 450 parts of acrylonitrile, 50 parts of methyl acrylate and 1181 parts of water were charged into a 2-liter autoclave, and di-tert-butyl peroxide was added as a polymerization initiator in an amount of 0.1 part based on the total amount of the monomers. After addition of 5% by weight, the mixture was sealed and then polymerized at 120 ° C. for 30 minutes under stirring. After completion of the reaction, the mixture was cooled to about 90 ° C. while continuing stirring, so that the average particle size was 38 μm.
m was obtained. 1 of this aggregated fine particle
When the secondary particles were observed with an electron microscope, the average particle size was found to be 0.2.
It was 3 μm. The obtained aggregated fine particles were subjected to hydrazine crosslinking and hydrolysis in the same manner as in Example 2, and further subjected to a pH adjustment treatment to obtain pH-buffered and humidity-controlling polymer fine particles. Table 1 summarizes the characteristics of the fine particles. As can be seen from the results, it was confirmed that the polymer fine particles had excellent pH buffering properties and humidity control properties. Further, the pH buffering property and the humidity control property were superior to Example 2, and the rate at which the pH buffer acted and the rate at which the humidity control equilibrium was reached were superior to Example 2. This is because the surface area was increased and the space between the primary particles worked effectively for diffusion of moisture and the like, and these gave good results, because Example 3 was in the form of aggregates of fine particles. Conceivable.

Example 4 The pH was adjusted in the same manner as in Example 1 using a strong acid ion exchange resin "DIAION SK 1B" manufactured by Mitsubishi Chemical having styrene / divinylbenzene as a polymer skeleton and a sulfonic acid group as a polar group. By performing the treatment, fine particles of a pH buffering / humidity controlling polymer were obtained. Table 1 summarizes the characteristics of the fine particles. As can be seen from these results, it was confirmed that the polymer fine particles had pH buffering properties and humidity control properties, but the effect was slightly inferior to Examples 1 to 3. This is considered to be the result of the large particle size and low ion exchange capacity.

Example 5 Softwood pulp and hardwood pulp were mixed at a weight ratio of 7: 3 and beaten to a Canadian standard freeness of 360 cc. This pulp was dispersed in water to prepare a pulp slurry having a concentration of 0.3% by weight.
Add humidity-controlling polymer fine particles at a concentration of 0.7% by weight.
-Papermaking was performed according to P8209. The content of the fine particles in the obtained product paper was 70% by weight, and the basis weight was 85 g / m2. Table 2 shows the results of evaluating the pH buffer and humidity control properties of the obtained paper. As can be seen from the table, good pH buffering and good humidity control were also observed for the obtained paper, confirming that the ability of the raw material fine particles was well expressed.

[0057]

[Table 2]

Example 6 Weight of 80 g made of 5 denier polypropylene fiber
A 20 g / m2 coarse hot melt nonwoven fabric is placed on the upper surface of the net-like nonwoven fabric having a thickness of 20 g / m2, and the pH-buffer / humidity-controlling polymer fine particles obtained in Example 3 are placed on the upper surface at 60 g / m2.
By sprinkling with an amount of m2 and bonding by heating, a non-woven fabric containing fine particles of a pH buffering / humidity controlling polymer was obtained. The nonwoven fabric had high air permeability and well maintained a layer of pH buffering / humidity controlling polymer fine particles. In addition, the pH buffer and the humidity control were also good as shown in Table 2, and it was confirmed that the raw material fine particles had good performance as in Example 5.

Example 7 The fine particles of the pH-buffered and humidity-controlling polymer obtained in Example 3 were mixed with a urethane resin according to the following formulation, and the mixture was cast on release paper and dry-foamed. A foamed urethane sheet was prepared. 100 parts of urethane resin (UF-3A, manufactured by Seiko Chemical) 10 parts of filler (FAD-130, manufactured by Seiko Chemical) 1 part of foaming agent (FAD-31, manufactured by Seiko Chemical) 13 parts of fine particles of pH buffering / humidity controlling polymer The composition was stirred with a disper for 30 minutes, mixed well, and cast on a release paper to a thickness of about 0.15 mm.
For 2 minutes to foam. The finished foam sheet thickness was 0.5 mm. This urethane foam sheet had about 10 g of pH-buffer / humidity-controlling polymer fine particles per 1 m 2.

Table 2 summarizes the results of evaluating the pH buffering and humidity control properties of the obtained urethane sheet. As shown in the table, the urethane sheet was confirmed to have good pH buffering and humidity control properties, and it was confirmed that the ability of the raw material fine particles was well expressed. Further, in the urethane sheet, the retention of the polymer is good, and it can be formed into various shapes.
Furthermore, since it has air permeability, it was a material suitable for filters and the like.

Comparative Example 1 Aggregated fine particles containing a carboxylic acid group were obtained by hydrazine cross-linking in the same manner as in Example 3 except that the hydrolysis with sodium hydroxide was performed at a reaction temperature of 60 ° C. and a reaction time of 1 hour.
When the pH buffering property and the humidity control performance of the particles were evaluated, they are as shown in Table 3, and the STD moisture absorption was as low as 12% by weight, and the drying condition moisture absorption was as low as 9% by weight. No function was expressed. This is considered to be due to the fact that the amount of the carboxylic acid group providing hydrophilicity was as low as 0.12 meq / g.

[0062]

[Table 3]

Comparative Example 2 Aggregated fine particles containing carboxylic acid groups were obtained by hydrazine crosslinking in the same manner as in Example 3 except that the crosslinking reaction with hydrazine was performed at 60 ° C. for 0.5 hour. P of the particle
When the H buffering property and the humidity control performance were evaluated, they were as shown in Table 3. The STD moisture absorption was as high as 160% by weight, but the particles were gel-like, sticky, and difficult to handle. Also, the moisture absorption at 20 ° C. and 80% RH is as high as 180% by weight, which is also gel-like and sticky.
It could not be handled as a particle powder due to aggregation. The moisture absorption of the same sample at 20 ° C. and 40% RH for 1 hour is 175% by weight, which is almost the same as that at 20 ° C. and 80% RH, and is very difficult to handle. Or, it was in a state where it could not be used as an additive to the sheet. In addition, although there was a moisture absorbing function, the moisture releasing function was hardly recognized, so that the function was insufficient in terms of the humidity control function. As described above, the reason why no change was observed in the moisture absorption rate was that the surface was in a hydrogel (highly water-absorbing polymer) state and the surface (the particles were solidified and the surface area was extremely small) was dried. However, it is presumed that the center was protected by the gel and no drying occurred. It is probable that such a phenomenon occurred because the crosslinking with hydrazine was very weak, resulting in a structure close to a hydrogel.

Comparative Example 3 Aggregate fine particles in which all of the carboxyl groups were sodium were obtained in the same manner as in Example 3 except that hydrolysis with caustic soda was carried out, followed by neither nitric acid treatment nor calcium nitrate treatment. Was. The pH buffering properties and humidity control performance of the fine particles were as shown in Table 3, and the humidity control properties were good. Also, the buffering action on the acid side was excellent,
No buffering action on the alkaline side was observed at all.

Comparative Example 4 The same procedure as in Example 3 was carried out except that hydrolysis with caustic soda was carried out, and only nitric acid treatment was carried out, and calcium nitrate treatment was not carried out. Fine particles were obtained. The pH buffering properties and humidity control performance of the fine particles were as shown in Table 3, and the humidity control properties were good. However, contrary to Comparative Example 3, although the buffering action on the alkali side was excellent, no buffering action on the acid side was observed.

Examples and comparative examples of cosmetics are described below. The feeling of use of the obtained cosmetics was evaluated as follows. (I) moist feeling, (ii)
For smooth feeling, (iii) smoothness, (iv) non-stickiness, and (v) smoothing effect, based on the judgment of good or bad when 20 specialized panelists applied to the face, the following four evaluation criteria (◎, ○, Δ, ×) were evaluated. Further, (vi) sustainability of smooth feeling and (vii) persistence of smoothness were similarly evaluated in four steps based on the judgment by a specialized panel according to the following criteria. Tables 4 and 5 summarize these results.

Evaluation criteria for use feeling 使用: 15 to 20 persons judged that the use feeling was good ○: 10 to 14 persons judged that the use feeling was good Δ: 5 to 9 persons judged that the use feeling was good ×: 4 or less used Judgment as good feeling Sustainability evaluation criteria A: 15 to 20 people judge that the feeling of use is persistent O: 10 to 14 people judge that the feeling of use is persistent Δ: 5 to 9 people have the feeling of use Judgment of presence x: 4 or less judged that the feeling of use was persistent

Example 8 According to the composition shown in Table 4, the raw materials excluding the pH buffering / humidity-controlling polymer fine particles were heated and stirred for 30 minutes in a reaction tank adjusted to a temperature of 60 ° C. to 85 ° C., and then cooled to room temperature. Next, into a pH buffered / humidity-controlling polymer fine particle previously stirred with a kneader,
The above-mentioned cooled raw materials were added and mixed and stirred until the mixture became uniform to prepare a paste-like cosmetic. The pH-buffered and humidity-controlling polymer fine particles used in Examples 8 and 9 were obtained by grinding the aggregate fine particles obtained in Example 3 with a bead mill,
Those having an average particle diameter of 10 μm were used. The cosmetics obtained as a result were excellent in moist feeling, smoothness, etc., and also excellent in persistence.

[0069]

[Table 4]

COMPARATIVE EXAMPLE 5 Similarly to the composition shown in Table 4, p obtained in Example 3
Paste cosmetics were prepared in the same manner as in Example 8, except that silicon dioxide fine particles having a similar average particle diameter were used instead of the H-buffer / humidity-controlling polymer fine particles. Although the smoothness was good, the moist feeling and the smooth feeling were poor, and the sustainability was of course poor. This is probably because the added inorganic particles do not have a humidity control function.

Comparative Example 6 Similarly to the composition shown in Table 4, p obtained in Example 3 was obtained.
Instead of the H-buffered / humidity-controlling polymer fine particles, the aggregate fine particles obtained in Comparative Example 1 were pulverized by a bead mill to have an average particle diameter of 10 μm, and used in the same manner as in Example 8 to obtain a paste-like cosmetic. It was created. The cosmetics are listed in Table 4.
As shown in Fig. 7, although the non-stickiness was good, the moist feeling, the smoothness was poor, and the sustainability was also a problem.
This result is considered to be due to the low humidity control of the fine particles of Comparative Example 1 used.

Example 9 An oil-in-water emulsion was prepared using the ingredients shown in Table 5 except for the guar rubber and the fine particles of the pH-buffer / humidity-controlling polymer obtained in Example 3. Next, guar gum and the microparticles were added and mixed by hand to create a smooth cream that could be applied to the skin. As shown in Table 5, the cream was a well-balanced and excellent cosmetic which was particularly excellent in moist feeling, smoothness and smoothing effect, and also excellent in persistence.

[0073]

[Table 5]

Comparative Example 7 and Comparative Example 8 Similarly to the formulation shown in Table 5, a paste-like cosmetic as Comparative Example 7 was prepared in the same manner as in the Example without using pH buffering / humidity-controlling polymer fine particles. did. Also,
The cream of Comparative Example 8 was prepared by adding disodium monohydrogen phosphate to Comparative Example 7 and adjusting the solution pH to 4.4. The obtained cream was, as shown in Table 5, Comparative Example 7
In this case, the pH is 6.7, which is not a weakly acidic region but a neutral region. As a result, no good results were obtained for any of the items. Further, in Comparative Example 8, the pH was in a weakly acidic range at 4.4, and the evaluation results tended to be better than Comparative Example 7. However, none of the evaluation items were at a practical level, and a preferable cosmetic was not obtained. . In particular, although a pH buffer such as disodium monohydrogen phosphate was added, the buffering action was only in the initial stage, resulting in extremely poor persistence.

Comparative Examples 9 and 10 Similarly, the p obtained in Example 3 was used in the same manner as shown in Table 5.
Instead of the H-buffer / humidity-controlling polymer fine particles, the fine particles obtained in Comparative Example 3 were used in Comparative Example 9, and the fine particles obtained in Comparative Example 10 were used in Comparative Example 10.
Using each of the fine particles obtained in the above, a cream was prepared. Each of the aggregated fine particles was pulverized by a bead mill to have an average particle diameter of 10 μm. Although the cream of Comparative Example 9 is good in terms of humidity control, p
There are problems such as high H, stickiness and lack of sustainability. In the cream of Comparative Example 10,
The pH was too high for the acid side, and good results were not obtained in the feeling during use. This is considered to be the result because the fine particles used had no pH buffering property.

As described above, the p of the present invention is higher than that of the comparative example.
Cosmetics using H-buffer / humidity-controlling polymer fine particles provide good results in any of moist feeling, smooth feeling, smoothness, non-stickiness, smoothing effect, smooth feeling persistence, and smoothness persistence. Have been. These are achieved by the pH buffering function and the humidity control function of the polymer of the present invention, and these excellent effects are maintained, even when sweat etc. It is considered that it has become an excellent cosmetic.

[0077]

It is a remarkable effect of the present invention that a polymer having both a pH buffering property and a humidity control property and a means for industrially producing the polymer can be provided. The pH-buffer / humidity-controlling polymer of the present invention can take various shapes. For example, it can be used as an additive in the form of powder or beads, or a paper, nonwoven fabric or foam sheet containing these. It can be used in the form. In addition, by including this in a cosmetic, a totally excellent cosmetic can be obtained.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C09K 3/00 C09K 3/00 N // A61K 7/00 A61K 7/00 J

Claims (15)

[Claims] 1. A polymer having an ion-exchange polar group and a crosslinked structure, which has a moisture absorption property of 20 ° C., 65%
The polymer has a moisture absorption rate of 15% by weight or more and 100% by weight or less under RH conditions, and has a moisture retention / desorption property of 20% at 80 ° C and 80% RH under saturation conditions at 20 ° C and 40% RH. The moisture absorption after leaving for 1 hour is 15% by weight or more and 80% by weight
It has a moisture control function that balances moisture absorption, moisture retention and moisture release, and the pH obtained by the buffer action of the polymer
PH buffer characterized in that the region is between 4 and 10
Humidity control polymer. 2. The pH-buffer / humidity-controlling polymer according to claim 1, wherein the ion-exchangeable polar group is any one of a sulfonic acid group, a carboxylic acid group and a phosphoric acid group. 3. The pH-buffer / humidity-controlling polymer according to claim 1, wherein the crosslinking structure is derived from a crosslinking agent of either divinylbenzene or triallyl isocyanurate. 4. A cross-linked structure obtained by reacting a nitrile group contained in a high nitrile polymer having a nitrile group-containing vinyl monomer content of 50% by weight or more with a hydrazine-based compound. The pH-buffered and humidity-controlling polymer according to claim 1 or 2, wherein 5. The pH-buffer / humidity-controlling polymer according to claim 4, wherein the vinyl monomer having a nitrile group is acrylonitrile. 6. The pH-buffer / humidity-controlling polymer according to claim 1, wherein the polymer is a particle having an average particle diameter of 100 μm or less. 7. The polymer has an average primary particle size of 5 μm.
The pH-buffer / humidity-controlling polymer according to any one of claims 1 to 6, wherein the pH-buffering polymer has an average particle diameter of 100 µm or less. 8. An ion-exchange polar group having an exchange capacity of 2.
The pH-buffer / humidity-controlling polymer according to any one of claims 1 to 7, wherein the pH-buffering polymer is 0 meq / g or more. 9. A hydrogen ion as a counter ion of an ion-exchangeable polar group and Ca and M as metal ions.
The pH-buffer / humidity-controlling polymer according to any one of claims 1 to 8, comprising any one of g, Na, K, Li, and Al. 10. The p according to claim 1, wherein
A sheet containing a pH-buffer / humidity-controlling polymer, which is any one of a paper, a nonwoven fabric, and a foam sheet containing an H-buffer / humidity-controlling polymer. 11. The p according to claim 1, wherein
A cosmetic comprising an H buffer / humidity controlling polymer. 12. A high-nitrile polymer having a vinyl monomer content of at least 50% by weight containing a nitrile group is treated with hydrazine to introduce a crosslinked structure, and then the remaining nitrile group is converted to a carboxylic acid by hydrolysis. Group, and acid or alkali to pH
PH buffer / humidity control wherein the equivalence ratio of hydrogen ions to metal ions is adjusted to a range of 1.0 to 1.5 to 4.0 to 1.0 after being adjusted to 4.0 to 7.0. A method for producing a polymer. 13. The method according to claim 12, wherein the vinyl monomer having a nitrile group is acrylonitrile. 14. The high nitrile polymer has an average particle size of 10
14. The method for producing a pH-buffer / humidity-controlling polymer according to claim 12, wherein the particles have a particle size of 0 μm or less. 15. The high nitrile polymer is an aggregate of particles having an average primary particle size of 5 μm or less, and the average particle size of the aggregate is 100 μm or less. 14. The method for producing a pH-buffered, humidity-controlling polymer according to 12 or 13.