JPS61183378A - Oily gel composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent shape retentivity and moldability, by incorporating a specified dispersion medium in the skeleton of (modified) PVA. CONSTITUTION:5-35wt% (modified) PVA having a viscosity-average degree of polymn. of 1,000 or above and a degree of saponification of 95mol% or above is dissolved in a sulfoxide compd. (e.g. dimethyl sulfoxide) which is liquid at room temp. as a dispersion medium. If desired, 0.1-200pts.wt. (per 100pts.wt. PVA) filler (e.g. CaCO3) and 0.01-100pts.wt. (per 100pts.wt. PVA) org. compd. (e.g. hemoglobin) are added to the resulting soln. While cooling, the mixture is left to stand to thereby cause it to gel, thus incorporating said dispersion medium in the skeleton of (modified) PVA. EFFECT:An oily gel compsn. which does not separate the sulfoxide compd. even under long-term storage conditions can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a polyvinyl alcohol oil gel composition containing a sulfoxide compound having unique properties as an organic solvent.

<Prior art> Gel-like compositions using polymeric materials are called hydrogels when the dispersion medium is water, and lyogels when the dispersion medium is organic solvent. It possesses the unique characteristics of a gel in a wet state, and has unique properties such as flexibility and material permeability compared to solid molded products in a dry state.

Hydrogels in which water is the dispersion medium have been actively researched for a long time, and have been widely used in various membrane materials, separation and purification materials such as carriers for liquid chromatography, materials for agriculture, forestry and fisheries such as artificial feed, and the water absorption properties of hydrogels. Applications are being actively developed in the fields of medicine, food, agriculture, forestry and fisheries, taking advantage of their water retention properties. Such polymeric materials include hydrophilic and water-insoluble materials, such as (meth)acrylic acid hydroxyalkyl ester, (meth)acrylic acid alkoxyalkyl ester, (meth)acrylic acid aminoalkyl ester, (meth)acrylic acid Homopolymers or copolymers such as polyvinyl alcohol, polyvinyl alcohol, etc. are used as they are or after crosslinking, and are used in a water-absorbed and swollen state.

On the other hand, lyogels can contain organic solvents that have excellent dissolution ability for general polymeric materials as dispersion media, so they can be given unique properties such as water resistance and substance solubility that are not found in hydrogels, making them suitable for a wide range of applications. This is something that we can look forward to further development.

<Problems to be solved by the invention> However, compositions related to lyogel have not been studied at all, and only some compositions using rubber-based polymer materials have been studied in the field of sanitary materials. do not have.

In view of the above-mentioned conventional technology, the present inventors have conducted extensive studies on oil-based gel, which is a lyogel that has excellent dissolving ability for various substances, and have found that polyvinyl alcohol, a type of hydrophilic polymer, It was discovered that a completely new oily gel-like material that can retain sulfoxide compounds having various specific functions as an organic solvent, has the specificity of sulfoxide compounds, and has excellent shape retention properties, leading to the present invention. It is.

<Means for solving the problems> That is, the present invention provides an oily gel composition containing a sulfoxide compound as a dispersion medium that is liquid at room temperature in a skeleton made of polyvinyl alcohol or a modified product thereof. It is something.

Polyvinyl alcohol or a modified product thereof (hereinafter referred to as polyvinyl alcohols), which is a component of the oil-based gel composition of the present invention, forms the skeleton of the composition in a gel state, and the sulfoxide compound is contained and retained in the gap between the skeletons of the composition. can be,
Therefore, any chain polymer that is uncrosslinked or intramolecularly or intermolecularly crosslinked can be used.

Furthermore, in the present invention, "polyvinyl alcohol or its modified product" includes not only completely saponified polyvinyl alcohol but also partially saponified polyvinyl acetate and poly(vinyl alcohol/copolymerizable monomer). It is.

By changing the blending ratio of the polyvinyl alcohols in the gel composition, the mechanical strength can be easily changed from weak to strong. It is preferable to change the properties because it does not change the amount of the M-containing sulfoxide compound. Examples of these measures include changing the degree of saponification and degree of polymerization, but in order to maintain practical shape retention during molding, the degree of saponification should be 95 mol% or more, and more preferably 97 mol% or more. is preferable.

In addition, the degree of polymerization of polyvinyl alcohols is determined by the shape retention when the polyvinyl alcohol becomes gel-like when the viscosity average degree of polymerization is set to 1000 or more, more preferably 1500 to 3300.

Since the oil-based gel composition has excellent moldability, it does not require shape retention and is suitable for applications that require uniform temperature distribution.

In the present invention, the sulfoxide compound used is a compound that is in a liquid state at room temperature, and serves as a dispersion medium when the polyvinyl alcohol is dissolved and gelled to form a gel composition.

These sulfoxide compounds are aprotic polar solvents that dissolve hydrophilic polymer substances extremely well, and include, for example, dimethyl sulfoxide, methyl ethyl sulfoxide, diethyl sulfoxide, dipropylsulfoxide, and dioctyl sulfoxide. Among these sulfoxide compounds, when the oil-based gel composition of the present invention is used in biological systems, dimethyl sulfoxide has relatively low acute oral toxicity and has a high flash point, from the viewpoint of safety in contact with living organisms. (hereinafter referred to as DMSO) is preferable, and is desirable in terms of solubility in polyvinyl alcohols and safety during the manufacturing process.

Since the above-mentioned sulfoxide compounds can dissolve various inorganic salts and various metal complexes to a considerable extent, they can be used as a medium for chelation reactions utilizing these.

The concentration of the polyvinyl alcohol in the oil-based gel composition of the present invention is not particularly limited, and can be arbitrarily changed depending on the mechanical strength of the target gel composition and the amount of the sulfoxide compound to be included. 5 to 35% by weight, preferably 10 to 25% by weight in terms of controllability of gelation rate and shape retention when the resulting composition is molded.
It is desirable that the range be within the range of . An oil-based gel composition can be obtained by gelling even at a concentration exceeding 35% by weight, but the solution viscosity is not high and the viscosity may increase during storage or a gelation reaction may occur spontaneously, making it difficult to handle. There is. In addition, if it is less than 5% by weight, the solution viscosity will be low, and the polyvinyl alcohol will not be able to sufficiently retain the sulfoxide compound even after the gelation reaction is completed, resulting in a soft gel composition with slightly poor shape retention. Become a thing.

An example of a method for producing the oil-based gel composition of the present invention is to dissolve a predetermined amount of polyvinyl alcohol in DMSO to form a solution, and then use the following ordinary gelling means to prepare the oil-based gel composition of the present invention. A gel composition is prepared. As a general gelling method, a) a solution is heated to a temperature of, for example, about 75° C. to form a uniform solution, and then allowed to stand at room temperature while being allowed to cool.

b) Gradually air dry in solution state.

C) Irradiating the solution with radiation such as electron beams or gamma rays.

d) Adding a gelling agent such as boric acid or borax (or an aqueous solution thereof) to the solution.

e) Freeze the solution at a low temperature of −15° C. or lower, shape it, and re-thaw it, or freeze and shape it and then perform a vacuum drying treatment and then thaw it, or repeat freezing and thawing several times.

Examples include.

The oil-based gel composition of the present invention can be obtained using such a gelling method, but the gelling method may also be performed after the solution is injected into a mold in the shape of the final object. Alternatively, the gel may be formed into a molded body of an appropriate shape and then molded into a desired shape by means such as slicing. The shapes of these molded bodies are granular, film-like, lump-like,
A plate shape, a cylindrical shape, or any other shape depending on the purpose is selected.

In the oil-based gel composition of the present invention, it is possible to make the skeleton of polyvinyl alcohol porous by selecting the above-mentioned gelling means. It is also possible to improve the diffusion mobility of the compound.

In the present invention, polyvinyl alcohol is used as a gelling component to provide an oil-based gel composition in which a sulfoxide compound that is liquid at room temperature is contained and retained. Various fillers such as , calcium carbonate, clays, and glass fibers can also be included in the composition. Furthermore, the sulfoxide compound contained as a dispersion medium exhibits unique solubility and acts as a good solvent for various organic and inorganic compounds.
Organic compounds such as heparin, chloroplast, proteins, enzymes, pharmaceuticals, phthalonitrile, phthalocyanine blue,
Inorganic compounds such as colorants such as frapinsulone, asbestos powder, and silica/alumina can also be blended and contained in a dissolved or suspended state.

The content of each of the above substances can be arbitrarily selected depending on the purpose of use and the type of the third component, but the filler As for 0.1~20
It is preferable that the amount of the organic compound be in the range of 0.01 to 100 parts by weight, or 0.1 to 100 parts by weight since it does not have a large effect on the properties of the gel composition itself.

In addition, for the purpose of improving the solubility of various additives that can be contained in the oil-based gel composition of the present invention, methyl alcohol, ethyl alcohol, propyl alcohol, octyl alcohol, glycols, and acetaldehyde, which can be freely mixed with sulfoxide compounds, are added. , an organic solvent such as acetone, dioxane, ethyl acetate, pyridine, dibutyl phthalate, or water may be added as appropriate.

Furthermore, among the sulfoxide compounds used in the present invention, D
MSO easily forms complex compounds by itself, and N,
It also has excellent solubility for complexes such as N'-bis(salicylideneimino) di-n-probylamine cobalt (II) and N,N'-bis(3-methoxysalicylidene) ethylenediamine cobalt (■). The oil-based gel composition of the present invention can also be applied to metal ion trapping and materials that utilize these properties.

<Effects of the Invention> As described above, the oil-based gel composition of the present invention contains polyvinyl alcohol, which is a hydrophilic polymer, or a modified product thereof, and a sulfoxide compound, which is an organic solvent, as a dispersion medium. By adjusting the amount of the oil-based gel composition, the mechanical strength of the molded product obtained from the oil-based gel composition can be changed, and various properties can be obtained, ranging from elastic and strong surface to soft and illy-like. I can do it. In addition, unlike general hydrogels, it is possible to contain substances that are not soluble in sulfoxide compounds, regardless of whether they are organic or inorganic compounds, so it is especially useful as a carrier to hold substances that contribute to some kind of reaction in a dissolved state. It is also useful as That is.

Since the oil-based gel composition of the present invention is in a wet state containing a sulfoxide compound, it exhibits an excellent effect on permeation and diffusion of substances, unlike solid-state compositions with a dense structure, and therefore is effective in preventing chemical reactions. Suitable for providing a field and selectively permeating various substances.

In addition to the above-mentioned properties, the oil-based gel composition of the present invention also has properties such as heat retention, lubricity, sustained release properties, etc., due to the fact that it is made into a gel-like material. It can be used in a wide range of applications, including as materials, heat-retaining materials, cold-retaining materials, heat-absorbing materials, lubricating materials, and slow-release materials.

<Examples> Examples of the present invention will be shown below and explained in more detail, but the present invention is not limited to these in any way, and various modifications can be made without departing from the technical idea.

In addition, the compressive stress value of the oil-based gel composition obtained in each Example was measured by the following method.

Rheometer (SUN KAGAKU CO, LTD.
A circular plunger with a diameter of 0.7511 mm (cross-sectional area of 0.384 mm) was buried in the oil-based gel composition of each Example to a depth of 4 mm using a 300 mm diameter (cross-sectional area: 0.384 mm).

Example 1 Powder 31.6y (water content 5%) of polyvinyl alcohol (saponification degree 99.0 mol%, viscosity average degree of polymerization 1500.4% by weight, aqueous solution viscosity 22 centipoise/20°C) was dissolved in dimethyl sulfoxide (DMSO). ) was dissolved in 90° C. under W heat at 80° C. to obtain a solution with a solid content concentration of 25.0% by weight, and then left at a temperature of 20° C. for 48 hours to obtain a bulk oily gel composition.

(Compressive stress 1650 g/cla) Example 2 Powder of polyvinyl alcohol (degree of saponification 99.4 mol%, viscosity average degree of polymerization 2600, 4% by weight aqueous solution viscosity 66 centivoise/20°C) 13. (1 (moisture content: 8% by weight)) was dissolved in 93.5t of DMSO under heating at 75°C to make a solution with a solid content concentration of 11.3% by weight, then placed in a petri dish to a thickness of 6m and air-dried for 72 hours. A plate-shaped oily gel composition was obtained.

(Compressive stress 80!i'/J) Example 3 Polyvinyl alcohol powder used in Example 1 21.
12 (water content 5% by weight) in DMSO78,99 at 80°C
After dissolving it under heating to make a solution with a solid content concentration of 20.0% by weight, put it in a petri dish with a thickness of 6 mm.
A plate-shaped oily gel composition was obtained by irradiation with an electron beam of 0 Mrad. (Compressive stress 1z4oy/cd) Example 4 Polyvinyl alcohol (saponified L 97.0 mo/I/%
, viscosity average degree of polymerization 1800.4% by weight aqueous solution viscosity 28
Centiboise/20℃) powder 21.5N (water content 7% by weight) was dissolved in DM8078.52 under heating at 80℃ to make a solution with a solid content concentration of 20.0% by weight, and then used as a gelling agent. 5 g of borax was added and dissolved to obtain a lumpy oil-based gel composition. (Compressive stress 1400 g/-) Example 5 The solution obtained in Example 3 was placed in a glass beaker, and -
The operation of freezing at 20°C and thawing at 20°C was repeated four times to obtain a lumpy oil-based gel composition.

(Compressive stress 1100y/cIl) Example 6 Polyvinyl alcohol (ii[tJi19.omol%,
An aqueous solution with a viscosity average degree of polymerization of 2000.4% by weight. Powder 21.57 (water content 5% by weight) with a viscosity of 22 centivoise/20'C) was dissolved in a mixed solvent of 58.5% DMSO and 20.0% water. After making a solution with a solid content concentration of 20.6% by weight, silica sand (5i02 content 95% by weight) was added as a filler.
) 52 and 5 g of borax as a gelling agent were added and dissolved to obtain a lumpy oil-based gel composition.

(Compressive stress 187 (1/J) The oil-based gel compositions obtained in each example did not separate DMSO even after long-term storage, and exhibited various characteristic values ranging from soft to extremely rubber elastic. It also showed good results when used as stress dispersion materials such as mats for sick people, cold insulation materials, and various sustained release materials.

Claims (1)

[Scope of Claims] 1) An oily gel composition containing a sulfoxide compound as a dispersion medium that is liquid at room temperature in a skeleton made of polyvinyl alcohol or a modified product thereof. 2) The oil-based gel composition according to claim 1, wherein the polyvinyl alcohol has a saponification degree of 95 mol% or more. 3) The viscosity average degree of polymerization of polyvinyl alcohol is 100
The oil-based gel composition according to claim 1 or 2, wherein the oil-based gel composition is 0 or more. 4) The oil-based gel composition according to claim 1, wherein the sulfoxide compound is dimethyl sulfoxide.