TW202016156A - Hydrogel - Google Patents

Abstract

A hydrogel according to the present invention has a polymer matrix obtained by polymerizing an acrylic monomer, an acrylic monomer, water, and a polyhydric alcohol, and the content of the acrylic monomer is 100 to 2000 ppm.

Description

Hydrogels

The present invention relates to a hydrogel having a polymer matrix obtained by polymerizing acrylic monomers, water and polyol.

A hydrogel is basically a polymer which has a high affinity for water and swells in an aqueous solvent. Hydrogels have various characteristics such as water absorption, swelling, moisture retention, adhesiveness, electrical conductivity, etc. according to their uses. These characteristics are utilized in a wide range of civil engineering, agronomy, food, medical, cosmetics, electrical, etc. In the field.

For example, Patent Document 1 discloses an adhesive gel (a hydrogel with adhesive properties) containing a polyol and water in a matrix of a hydrophilic polymer and an acrylamide polymer. The adhesive gel is suitable for sticking to the surface of the body while maintaining the adhesiveness when the water content is reduced, and has the characteristics of low skin irritation and softness.

In addition, Patent Document 2 discloses an adhesive gel in which acrylamide as a polymerizable monomer and N,N'-methylenebisacrylamide as a crosslinkable monomer are copolymerized. The resulting polymer matrix maintains a non-crosslinked water-soluble polymer and water with a weight average molecular weight of 40,000 to 150,000. The adhesive gel system has low skin irritation, and can contain conductivity by containing electrolyte salts. In addition, this adhesive gel system has no reduction in adhesion when peeled from the adherend, and is excellent in repeated adhesion.

[Prior Technical Literature] [Patent Literature]

[Patent Literature 1] Japanese Patent Laid-Open No. 2012-107120

[Patent Document 2] Japanese Patent Laid-Open No. 2003-96431

In addition, in the hydrogels hitherto, from the viewpoint of low skin irritation, discoloration (yellowing) of the gel, and deodorization, the monomer components forming the polymer matrix are usually polymerized reliably, and the hydrogel The amount of residual monomer in is very close to zero. For example, in Patent Document 2, the amount of the ultraviolet polymerization initiator in the monomer preparation solution is set to 0.5% by weight, and the ultraviolet irradiation amount is set to 50 mW/cm ² and irradiated for 60 seconds, and the residual form in the hydrogel is The volume is set to 0 ppm.

Hydrogels made by the polymerization of such monomer components are also excellent in adhesion, and have appropriate hardness, but today, still seeking a hydrogel that has adhesion and high hardness according to the application .

The object of the present invention is to provide a hydrogel with high adhesion and high storage elastic modulus.

The present inventors have unexpectedly found that polymerization is not carried out at all, that is, by leaving unreacted monomers in an appropriate amount of hydrogel, the previous adhesion of the hydrogel can be maintained and the hardness can be improved. The present invention was completed by the inventors and the like after further repeated research.

According to the first aspect of the present invention, it is possible to provide a hydrogel having a polymer matrix obtained by polymerizing an acrylic monomer, an acrylic monomer, water, and a polyol, and the acrylic monomer The content of the body is 100 to 2000 ppm.

In one embodiment, the acrylic monomer is an acrylamide monomer.

In another embodiment, the hydrogel has an intermediate base material embedded in the in-plane direction.

In another embodiment, the intermediate substrate is a non-woven fabric.

In another embodiment, the storage elastic modulus of the hydrogel at a frequency of 0.1 Hz is 2000 to 9000 Pa.

In another embodiment, the adhesion of the hydrogel to the backlight board is 1 to 15 N/20 mm.

According to the second aspect of the present invention, a hydrogel for medical electrodes can be provided. The hydrogel for medical electrodes is disposed between an electrode element composed of a conductive material and the surface of the skin and is used by a user. The hydrogel is described.

According to the third aspect of the present invention, a method for manufacturing a hydrogel can be provided. The hydrogel is water having a polymer matrix obtained by polymerizing acrylic monomers, acrylic monomers, water, and polyol Gel, and this manufacturing method makes the reaction rate of the aforementioned acrylic monomer 99.99 to 99.80%.

The invention can provide a hydrogel with high adhesive force and high storage elastic modulus.

1‧‧‧gel tablets

10‧‧‧gel material

12‧‧‧Intermediate base material

14‧‧‧ basement membrane

16‧‧‧Top film

Fig. 1 (A) is a schematic plan view of an embodiment of a gel sheet, and (B) is a schematic cross-sectional view taken along line 1B-1B of the gel sheet of Fig. 1 (A).

[Hydrogels]

The hydrogel of the present invention (hereinafter, also simply referred to as "hydrogel" or "gel") has a polymer matrix obtained by polymerizing an acrylic monomer, an acrylic monomer, water, and a polyol. The so-called acrylic single system has an acrylic group (H ₂ C=CH-C(=O)-) or methacrylic group (H ₂ C=C(CH ₃ )-C(=O)-). Generic term for monomers that can form polymers (polymers) by polymerization.

As an example, the aforementioned polymer matrix may be formed of a copolymer of a monofunctional monomer belonging to an acrylic monomer and a crosslinkable monomer, but it is not limited thereto.

The aforementioned monofunctional monomer is not particularly limited, but is preferably a water-soluble monomer such as a (meth)acrylamide-based monomer or a (meth)acrylate.

Specific examples of the aforementioned (meth)acrylamide-based monomers include: (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth N) N-dialkyl (meth) acrylamide; N-isopropyl (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl N-alkyl (meth) acrylamide such as (meth) acrylamide, N-propyl (meth) acrylamide; N-hydroxyethyl (meth) acrylamide, N-hydroxymethyl N-hydroxyalkyl (meth)acrylamide such as (meth)acrylamide; N-ethoxymethyl (meth)acrylamide, N-propoxymethyl (meth)acrylamide , N-butoxymethyl (meth) acrylamide, N-isobutoxymethyl (meth) acrylamide, N-pentoxymethyl (meth) acrylamide, N-hexyl Oxymethyl (meth) acrylamide, N-heptoxymethyl (meth) acrylamide, N-octyloxymethyl (meth) acrylamide, N-ethoxyethyl ( Meth) acrylamide, N-propoxyethyl (meth) acrylamide, N-butoxyethyl (methyl) N-alkoxyalkyl (meth)acrylamide such as acrylamide; cationic acrylamide-based compounds containing an amine group such as dimethylaminopropyl (meth)acrylamide; 4-acrylamide Sulfo group-containing anionic monofunctional monomers or salts thereof such as morpholine, tertiary butylacrylamide sulfonic acid; and derivatives thereof. Among them, preferably selected from (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl (Meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-hydroxyethyl ( Meth) acrylamide, N-hydroxymethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, 4-propenyl morpholine, tert-butyl acrylamide One kind or two or more kinds in the group formed by sulfonic acid and its salt, but it is not limited thereto.

Specific examples of the aforementioned (meth)acrylates include alkyl (meth)acrylates having an alkyl carbon number of 1 to 18, for example, selected from the group consisting of methyl (meth)acrylate and ethyl (meth)acrylate Ester, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, third butyl (meth)acrylate, (A Group) n-hexyl acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, (meth) acrylate Isononyl ester, n-pentyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-lauryl (meth)acrylate, tridecyl (meth)acrylate , Alkyl (meth)acrylates such as n-stearyl (meth)acrylate; cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, etc. ( Alicyclic methacrylate; 2-methoxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, etc. (Meth)acrylic acid methoxypolyethylene glycol esters and other (meth)acrylates containing alkoxy; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, (meth ) 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxybutyl (meth)acrylate, etc. (the hydroxyalkyl group can be bonded to the aryl group through an ether bond) hydroxyalkyl (meth)acrylate ; Glycerol mono(meth)acrylate; Poly(ethylene glycol) mono(meth)acrylate and polyalkylene glycol mono(meth)acrylate such as polyethylene glycol-polypropylene glycol copolymer; (Meth)acrylates with aromatic rings such as benzyl (meth)acrylate; and one or two of the group consisting of (meth)acrylates with heterocycles such as tetrahydrofuran methyl (meth)acrylate Above, but not limited to this.

The crosslinkable monomer is preferably a monomer having two or more polymerizable double bonds in the molecule. Specific examples include methylene bis(meth)acrylamide, ethylene bis(meth)acrylamide, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth) Base) acrylate, glycerol di(meth)acrylate, glycerol tri(meth)acrylate and other multifunctional (meth)acrylamide or multifunctional (meth)acrylate, tetraallyloxyethane, Diallyl ammonium chloride and the like can be used alone or in combination of two or more. In addition, the above-mentioned cross-linkable monomer having two or more polymerizable double bonds in the molecule can also be used as described in Japanese Patent No. 2803886, which has two or more (meth)acryloyl or vinyl groups and has a molecular weight It is a polyglycerin derivative of a polyfunctional compound of 400 or more. The polyfunctional (meth)acrylamide, the polyfunctional (meth)acrylate, and the polyglycerol derivative are contained in acrylic monomers.

The addition amount of the crosslinkable monomer is preferably in the range of 0.02% to 1.5% by weight relative to the total amount of the polymer matrix. If the addition amount is set to 0.02% by weight or more, the cross-linking density can be maintained, the shape stability is good, and the cohesive force can be maintained, the retention of the gel material itself can be maintained, and the adhesion can be sufficiently improved. In addition, when peeling off, the gel material can be peeled off smoothly from the adherend, and the gel sheet has good handleability. In addition, if the amount of the crosslinkable monomer added is 1.5% by weight or less, the adhesive force can be maintained to a high degree, and a soft gel can be formed. In addition, in this specification, "weight%" may also be expressed as "mass%".

The hydrogel system of the present invention has an acrylic monomer as a monomer, which is different from a polymer matrix as a polymer obtained by polymerizing an acrylic monomer. Regarding the acrylic monosystem, the monofunctional monomer made of the acrylic monomer constituting the polymer matrix is as described above. By allowing the acrylic monomer to remain in the hydrogel in an appropriate amount, the hydrogel's previous adhesion can be maintained, and Increase hardness. The remaining amount of the acrylic monomer can be measured by a known method in accordance with the acrylic monomer used in the production of hydrogels.

For example, when the acrylic monomer is acrylamide, a 2.5% phosphoric acid aqueous solution can be added to the sample and then filtered with a filter, by supplying the resulting filtrate to high-performance liquid chromatography (HPLC) (eluent: 0.1% Phosphoric acid aqueous solution, flow rate: 1.0 mL/min, room temperature, detection wavelength: 210 nm), and the residual amount of acrylamide was measured. When the acrylic monomer is acrylate, a solution of 0.05%-TFA/acetonitrile=95/5 can be added to the sample and dissolved, then filtered with a filter, by supplying the resulting filtrate to high-performance liquid chromatography ( HPLC) (elution solution: 0.05%-TFA/acetonitrile=95/5 solution, flow rate: 1.0 mL/min, column temperature: 40° C., detection wavelength: 210 nm), the residual amount of acrylamide was determined.

The content of the acrylic monomer in the hydrogel of the present invention is not particularly limited, and the lower limit is preferably 100 ppm, and the upper limit is preferably 2000 ppm. When the content of the acrylic monomer does not reach the aforementioned lower limit, the hardness of the hydrogel may not be increased. When the content of the acrylic monomer exceeds the aforementioned upper limit, skin irritation may increase. The lower limit of the content of the acrylic monomer is more preferably 200 ppm, and the lower limit is more preferably 300 ppm. The more preferable upper limit of the content of the acrylic monomer is 1000 ppm, and the more preferable upper limit is 500 ppm.

The content of water in the hydrogel is not particularly limited, and it is preferably 10 to 60 parts by mass, and more preferably 15 to 30 parts by mass relative to 100 parts by mass of the hydrogel. If the water content is too small, the water content becomes less than the equilibrium moisture content of the hydrogel, the hygroscopicity of the hydrogel becomes stronger, and the hydrogel may undergo temporal deterioration (for example, swelling). In addition, if the water content is too large, the water content will increase with respect to the equilibrium moisture content of the hydrogel, and the hydrogel may shrink or physical properties may change due to drying.

The polyol system is added to impart wettability to the hydrogel. The polyol is not particularly limited, and examples thereof include diethylene glycol, triethylene glycol, 1,6-hexanediol, 1,9-nonanediol, propylene glycol, and butylene glycol. Alcohol; glycerin, neopentyl alcohol, sorbitol and other polyvalent alcohols with a price of more than 3; polyhydric alcohol condensates such as polyethylene glycol, polypropylene glycol, and polyglycerol; modified polyhydric alcohols such as polyoxyethylene glycerol.

Among the polyhydric alcohols, it is preferred that the hydrogel is used in a liquid temperature range (for example, around 20°C when used indoors) that is a liquid polyhydric alcohol, specifically, it is suitably selected from ethylene glycol, triethylenedioxide One, two or more of alcohol, propylene glycol, polypropylene glycol, polyethylene glycol, polyglycerin, and glycerin.

The content of the aforementioned polyol in the hydrogel is not particularly limited, but it is preferably in the range of 20 to 70 parts by mass relative to 100 parts by mass of the hydrogel, more preferably in the range of 25 to 65 parts by mass . If the content of the aforementioned polyol is too small, the resulting hydrogel lacks moisturizing power and plasticity, water evaporation becomes significant, the hydrogel lacks stability over time, and lacks flexibility, so sufficient adhesion may not be obtained Sexual situation. In addition, if the content of the above-mentioned polyol is too large, the amount of the polyol that can maintain the polymer matrix is exceeded, and the physical properties caused by the polyol oozing from the surface of the hydrogel may occur, and sufficient adhesion may not be obtained. , So consider these balances and set appropriately.

In addition, the hydrogel system of the present invention may contain an electrolyte as needed, thereby imparting conductivity to the hydrogel.

The electrolyte is not particularly limited, and examples thereof include alkali halide metals such as sodium halide, lithium halide, and potassium halide; alkali halide alkaline earth metals such as magnesium halide and calcium halide; and other metal halides. In addition, as the electrolyte, hypochlorite, chlorite, chlorate, perchlorate, hydrochloride, sulfate, carbonate, nitrate, and phosphate of various metals can also be used as appropriate. In addition, the above electrolytes are also suitable for inorganic salts such as ammonium salts and various miscellaneous salts; salts of monovalent organic carboxylic acids such as acetic acid, benzoic acid, and lactic acid; salts of polyvalent organic carboxylic acids such as tartaric acid; phthalic acid, succinic acid, and hexanoic acid Salts of polyvalent carboxylic acids such as diacid and citric acid with one or more valences; metal salts of organic acids such as sulfonic acid and amino acids; and organic ammonium salts.

When imparting conductivity to the hydrogel, the content of the electrolyte in the hydrogel is preferably 0.05 to 10 parts by mass, and more preferably 0.1 to 6 parts by mass relative to 100 parts by mass of the hydrogel. If the content of the electrolyte is too small, the impedance becomes high, making it difficult to say that it has good conductivity. In addition, although the impedance will decrease as the electrolyte content increases, if the electrolyte content is too large, the impedance will no longer decrease, and the cost will be wasted.

In addition, for the purpose of adjusting the pH of the hydrogel system, an alkali such as sodium hydroxide can be appropriately added.

In addition, the hydrogel of the present embodiment is for the purpose of obtaining optimum adhesive force, and may contain water-soluble polymers such as polyacrylic acid or its salt according to needs.

Examples of such a water-soluble polymer include a copolymer of acrylic acid and methacrylic acid, a polymer containing N-alkylsulfonic acid acrylamide in a structural unit, and the like. These systems can be used alone or in combination.

The copolymer of acrylic acid and methacrylic acid preferably has a copolymerization ratio (molar ratio) of acrylic acid and methacrylic acid of 9:1 to 1:9.

When the content of the copolymer of acrylic acid and methacrylic acid is too small, it is difficult to obtain the desired adhesive force. On the contrary, if too much the hydrogel becomes hard, resulting in a decrease in the adhesive force, so it is appropriately set in consideration of these balances . Specifically, the content of the copolymer of acrylic acid and methacrylic acid is preferably 0.03 to 3 parts by mass, more preferably 0.2 to 2 parts by mass relative to 100 parts by mass of the hydrogel.

The copolymer of acrylic acid and methacrylic acid can be produced by methods such as radical polymerization, redox reaction, and light irradiation. For such a copolymer of acrylic acid and methacrylic acid, commercially available products such as Jurymer AC-20H, AC-20L (trade name) manufactured by East Asia Synthetic Corporation, or FL-200 (trade name) manufactured by Nippon Catalyst Corporation can also be used. .

The weight-average molecular weight of the polymer containing N-alkylsulfonic acid propylene amide in the structural unit is not particularly limited, but for ease of preparation of the preparation liquid and to exert the most suitable adhesive force of the resulting hydrogel, it is 7 million or less. Better. In addition, in order to obtain a gel with agglutinating properties, 500,000 or more is preferable.

The content of the polymer containing N-alkylsulfonic acid acrylamide in the structural unit is preferably 0.1 to 40 parts by mass, more preferably 0.4 to 15 parts by mass, relative to 100 parts by mass of the hydrogel. Alternatively, it is preferably 0.1 to 40% by weight relative to the hydrogel, and more preferably 0.4 to 15% by weight.

The polymer containing N-alkylsulfonic acid acrylamide in the structural unit may also be a copolymer with other polymers. Examples of the commercially available copolymers mentioned above include copolymers of acrylic acid and propylene amide of N-alkylsulfonic acid. Specifically, a copolymer of acrylic acid and acrylamide methyl propane sulfonic acid (ARON Bi-AH-305 (trade name) manufactured by Toa Synthesis Co., Ltd.) and the like can be used.

When the polymer containing N-alkylsulfonic acid acrylamide is a copolymer with other polymers, the copolymerization ratio (mole ratio) is preferably the polymerization of N-alkylsulfonic acid acrylamide Object: Other polymers = 2:8 to 8:2, preferably 2:8 to 5:5.

Furthermore, the hydrogel may contain other additives as needed. Other additives include, for example, rust inhibitors, mildew inhibitors, antioxidants, defoamers, stabilizers, surfactants, colorants, and the like.

[Manufacturing method of hydrogel]

The hydrogel system can be obtained by uniformly dispersing the materials other than the above-mentioned water and the polymerization initiator in water, and heating and dispersing the dispersion to perform polymerization and crosslinking. In addition, the dispersion system includes not only the state in which the solute is dispersed in water without being mixed with water, but also the dissolution of a mixture in which the solute and water are mixed to form a homogeneous phase.

The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator, and a well-known thermal polymerization initiator or photopolymerization initiator for polymerizing acrylic monomers may be used. In addition, the content of the polymerization initiator is not particularly limited, but it is 0.01 parts by mass relative to 100 parts by mass of the polymerization initiator removed from the dispersion liquid (also referred to as a monomer formulation liquid) of the composition before polymerization The above is preferred, and 1 part by mass or less is preferred. Furthermore, when polymerization is carried out by ultraviolet irradiation, the cumulative irradiation amount of ultraviolet rays also varies according to the content of the polymerization initiator, etc., but is preferably in the range of 800 mJ/cm ² to 10000 mJ/cm ² , for example, 2000 mJ/ The range of cm ² to 10000 mJ/cm ² is more preferable.

In the present invention, by appropriately setting the amount of the polymerization initiator and the amount of ultraviolet irradiation, the reaction rate of the acrylic monomer can be appropriately adjusted to be 99.99 to 99.80%. Furthermore, by appropriately setting the amount of the polymerization initiator and the amount of ultraviolet irradiation, the reaction rate of the acrylic monomer can be appropriately adjusted in such a way that a part of the acrylic monomer can remain, so that a polymer matrix, acrylic The hydrogel of the present invention having a monomer, water and polyol, and an acrylic monomer content of 100 to 2000 ppm.

The hydrogel can be formed into a desired shape such as a sheet by pouring a monomer preparation solution into a container having a desired shape such as a bottomed container having a substantially rectangular cross-section, and polymerizing it by ultraviolet irradiation or the like. The shape of the sheet formed into a sheet-shaped hydrogel may be any shape according to the purpose, and examples thereof include approximately rectangular and approximately circular, but are not limited thereto. Hereinafter, the sheet-shaped hydrogel is called "hydrogel sheet" or simply "gel sheet".

[Further Composition of Hydrogels and Gel Sheets]

The hydrogel of the present invention is preferably embedded with an intermediate substrate along the in-plane direction. Here, the in-plane direction of the hydrogel means any direction in a plane orthogonal to the thickness direction of the hydrogel. By having an intermediate base material, it is related to the reinforcement of the hydrogel and the improvement of shape retention during cutting. The specific aspect of the aforementioned intermediate substrate may be composed of non-woven fabric or woven fabric. Non-woven fabrics and woven fabrics can use cellulose, silk, hemp and other natural fibers; polyester, nylon, rayon, polyethylene, polypropylene, polyurethane, etc. Synthetic fibers, or these blends, can also use binders as needed, and can be colored as needed.

The manufacturing method of the aforementioned non-woven fabric is not particularly limited, but examples thereof include dry method or wet method, spinning bonding method, melt blown method, EAR RAID method, chemical bonding method, thermal bonding method, and needle punching (Needle) punch) method, water flow entanglement method. It adopts the manufacturing method according to the unit weight or material. In order to control the position of the intermediate base material, it is better to have no unit weight unevenness. The woven fabric is not particularly limited, but plain weave, warp knitting, Rachel (RASCHEL), etc. are appropriately selected.

In addition, the unit weight of the woven or non-woven fabric is not particularly limited as long as it can obtain a predetermined physical property as an intermediate base material. For example, 10 to 40 g/m ² is preferable, and 10 to 28 g/m is preferable. ² is better. If the unit weight of the woven or non-woven fabric is too small, the reinforcement of the gel sheet cannot be sought, the unevenness of the unit weight becomes larger, or the liquid permeability during the manufacture of the gel sheet varies depending on the location, thereby making it possible to intermediate the substrate The position of the position changes. In addition, if the unit weight is too large, the intermediate base material becomes hard, which may damage the followability of the hydrogel to the skin or adversely affect the conductivity. Therefore, the balance is appropriately set.

If the thickness of the aforementioned intermediate base material is too thick, the liquid permeability may be deteriorated and adversely affect the conductivity. On the contrary, if it is too thin, it is the same as the case where the unit weight is too small. The reinforcement of the film, etc., or the position of the intermediate substrate may change, so consider this and set appropriately. It is preferably in the range of 0.05 mm to 2.0 mm. Furthermore, 0.05 mm to 0.5 mm is more preferable, and 0.08 mm to 0.3 mm is particularly preferable.

The thickness of the hydrogel of the present invention is selected in consideration of such a situation that the shear stress decreases when it is too thick, and the cohesive force decreases when it is too thin. It is preferably in the range of 0.2 mm to 2.0 mm. In particular, 0.3 mm to 1.2 mm is preferred, and 0.3 mm to 1.0 mm is more preferred.

The storage elastic modulus (the frequency of 0.1 Hz) of the hydrogel of the present invention is not particularly limited, but the preferred lower limit is 2000 Pa, and the preferred upper limit is 9000 Pa. If the storage elastic modulus does not reach the aforementioned lower limit, the gel becomes too soft, and there is a concern that the workability when processing into a specific shape is reduced due to lack of handling or shape stability. If the storage elastic modulus exceeds the aforementioned upper limit, the gel becomes too hard. Although the operability or processability can be improved, the adhesive force may be too low. The lower limit of the storage elastic modulus of the hydrogel of the present invention is more preferably 3000 Pa, and the even better lower limit is 4000 Pa. The upper limit of the storage elastic modulus of the hydrogel is 8000 Pa, and the upper limit is 7000 Pa.

The adhesion of the hydrogel of the present invention to the backlight is not particularly limited, but the preferred lower limit is 1N/20mm, and the preferred upper limit is 15N/20mm. If the adhesive force does not reach the aforementioned lower limit, the adhesive force to the skin is insufficient, and there is a possibility that the gel may fall off the device when forming the electrode. If the adhesive force exceeds the aforementioned upper limit, the adhesive force to the skin is too strong, and there may be pain or redness during peeling. The lower limit of the better adhesion of the hydrogel of the present invention to the backlight board is 2N/20mm, and the better lower limit is 3N/20mm. The upper limit of the adhesive force of the hydrogel of the present invention to the backlight board is better at 9N/20mm, and the better upper limit is at 7N/20mm.

The manufacturing process of the hydrogel sheet with the intermediate base material has different fine conditions according to the composition of the gel material, the material of the intermediate base material, the thickness, etc., but it is not particularly limited. For example, the following method may be suitably used: in a manner that minimizes the vertical deformation of the intermediate substrate, the intermediate substrate is kept in the air with a certain amount of tension applied, above and below the intermediate substrate On the side, a method of flowing into the monomer formulation liquid and polymerizing it by light irradiation to make it into a sheet shape; after making two gel materials with a smooth sheet shape, the intermediate base is maintained in a state where a certain amount of tension is applied The method is to hold the gel material and compound it; or, to make a gel material with a smooth surface, place the intermediate substrate on the gel material in a state of applying a certain amount of tension , The monomer preparation solution flows into the middle substrate, The method of further polymerizing by light irradiation or the like. When such a manufacturing process is a continuous process, the intermediate base material or gel material may be rolled, and then taken out and cut into appropriate sheets.

FIG. 1(A) shows an approximate plan view of one embodiment of the gel sheet, and FIG. 1(B) shows a cross-sectional view of the gel sheet of FIG. 1(A) taken along line 1B-1B. The gel sheet 1 includes a gel material 10 composed of the hydrogel of the present invention, and an intermediate substrate 12 embedded in the gel material 10. In this embodiment, the base film 14 is provided on one side of the gel sheet 1, and the top film 16 is provided on the back surface of the surface on which the base film 14 is provided, but the base film 14 and the top film 16 may be omitted.

For the base film 14, for example, a resin film made of resins such as polyester, polyolefin, polystyrene, and polyurethane, paper, and paper formed by laminating the foregoing resin film can be used.

The surface where the base film 14 is in contact with the gel sheet 1 is preferably subjected to release treatment. The method of the release treatment may include polysiloxane coating, etc. In particular, baking-type polysiloxane coating which is cross-linked and hardened by heat or ultraviolet rays is preferred. The film subjected to the release treatment is particularly preferably a biaxially stretched PET (polyethylene terephthalate) film, OPP (stretched polypropylene) film, or the like.

The top film 16 can basically be made of the same material as the base film, but in the state where the top film is provided, ultraviolet light irradiation or the like is used to polymerize the film, so as not to hinder photopolymerization, it is preferably selected Film that does not block light.

The hydrogel of the present invention is excellent in flexibility, water retention, etc., so it can be used in various fields including medical treatment, cosmetics, food, chemistry, civil engineering, agriculture, biomass engineering, sports connection, etc. For example, medical electrode hydrogel, cooling gel, cosmetic mask, cell culture medium, etc. can be used. It is preferable to use a medical electrode hydrogel that is disposed between an electrode composed of a conductive material and the skin surface.

The present invention may also adopt the following configuration.

(1) A hydrogel having a polymer matrix obtained by polymerizing an acrylic monomer, an acrylic monomer, water, and a polyol, and having an acrylic monomer content of 100 to 2000 ppm.

(2) The hydrogel according to (1), wherein the acrylic monomer is an acrylamide monomer.

(3) The hydrogel according to (1) or (2), in which the intermediate base material is embedded along the in-plane direction.

(4) The hydrogel according to (3), wherein the intermediate substrate is a non-woven fabric.

(5) The hydrogel according to any one of (1) to (4), wherein the content of water in the hydrogel is 10 to 60 parts by mass relative to 100 parts by mass of the hydrogel.

(6) The hydrogel according to any one of (1) to (4), wherein the content of water in the hydrogel is 15 to 30 parts by mass relative to 100 parts by mass of the hydrogel.

(7) The hydrogel according to any one of (1) to (6), wherein the polyhydric alcohol is selected from the group consisting of diols, polyhydric alcohols having a valence of 3 or more, polyhydric alcohol condensation-free, and polyhydric alcohol modified products One or more than two of the group.

(8) The hydrogel according to any one of (1) to (7), wherein the polyol is selected from the group consisting of ethylene glycol, triethylene glycol, propylene glycol, polypropylene glycol, polyethylene glycol, and polyglycerol 1 or 2 or more in the group formed by glycerin.

(9) The hydrogel according to any one of (1) to (8), wherein the content of the polyol in the hydrogel is 20 to 70 parts by mass relative to 100 parts by mass of the hydrogel.

(10) The hydrogel according to any one of (1) to (8), wherein the content of the polyol in the hydrogel is 25 to 65 parts by mass relative to 100 parts by mass of the hydrogel.

(11) The hydrogel according to any one of (1) to (10), which further contains an electrolyte.

(12) The hydrogel according to (11), wherein the electrolyte is a halogenated alkali metal or a halogenated alkaline earth metal.

(13) The hydrogel according to (11) or (12), wherein the electrolyte is sodium chloride.

(14) The hydrogel according to any one of (11) to (13), wherein the content of the electrolyte in the hydrogel is 0.05 to 10 parts by mass relative to 100 parts by mass of the hydrogel.

(15) The hydrogel according to any one of (11) to (13), wherein the content of the electrolyte in the hydrogel is 0.1 to 6 parts by mass relative to 100 parts by mass of the hydrogel.

(16) The hydrogel according to any one of (1) to (15), which further contains a water-soluble polymer.

(17) The hydrogel according to (16), wherein the water-soluble polymer is a copolymer of acrylic acid and methacrylic acid, and at least one of the polymers containing N-alkylsulfonic acid acrylamide as a constituent unit One kind.

(18) The hydrogel according to (17), wherein the water-soluble polymer is a copolymer of acrylic acid and methacrylic acid, and the content of the copolymer of acrylic acid and methacrylic acid with respect to 100 parts by mass of the hydrogel is 0.03 to 3 parts by mass.

(19) The hydrogel according to (17), wherein the water-soluble polymer is a polymer containing N-alkylsulfonic acid propylene amide, and contains N-alkyl groups with respect to 100 parts by mass of the hydrogel The content of the polymer of propylene amide sulfonate is 0.1 to 40 parts by mass.

(20) The hydrogel according to any one of (1) to (19), wherein the storage elastic modulus at a frequency of 0.1 Hz is 2000 to 9000 Pa.

(21) The hydrogel according to any one of (1) to (20), wherein the adhesive force to the backlight plate is 1 to 15 N/20 mm.

(22) A hydrogel for medical electrodes, which is arranged between an electrode element composed of a conductive material and the surface of the skin and used by a user, and is a hydrogel according to any one of items (1) to (21) Posed.

(23) A method for manufacturing a hydrogel, which is such that the reaction rate of the acrylic monomer is 99.99 to 99.80%, wherein the hydrogel has a polymer matrix obtained by polymerizing acrylic monomers , Acrylic monomers, water, and polyols.

(24) A method for manufacturing a hydrogel, which includes a step of polymerizing a dispersion containing an acrylic monomer, water, and a polyol, and the reaction rate of the acrylic monomer is set to 99.99 to 99.80%, wherein the hydrogel has a polymer matrix obtained by polymerizing acrylic monomers, acrylic monomers, water, and polyol.

(25) The production method according to (24), wherein the dispersion liquid contains a polymerization initiator, and the content of the polymerization initiator is 0.01 mass relative to 100 parts by mass of the polymerization liquid from which the polymerization initiator is removed. Not less than 1 part by mass.

[Example]

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to these Examples.

1. Modulation of hydrogel

Preparation of the hydrogel of Example 1

(1) The preparation of monomer blending solution

Using a stirring/mixing vessel, as shown in Table 1, the total amount of acrylamide as a non-crosslinkable monofunctional monomer and methylene bisacrylamide as a crosslinkable monomer was 20.042% by weight, ion exchange 18% by weight of water, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (product name " IRGACURE (registered trademark) 2959", manufactured by BASF Japan Co., Ltd.) 0.03% by weight, mixed and stirred to uniformly dissolve, then added 57.55% by weight of glycerin as a moisturizing agent, and stirred as described above until uniform. Next, add 2.5% by weight of sodium chloride as an electrolyte and 1.178% by weight of sodium benzoate and citric acid as other additives, stir until completely dissolved, and finally add an acrylic-methacrylic acid copolymer as a water-soluble polymer (Jurymer AC-20H, manufactured by East Asia Synthetic Corporation) 0.70% by weight to obtain a transparent monomer formulation liquid.

(2) Manufacture of hydrogel

Drop the resulting monomer formulation onto the PET film coated with polysiloxane, place the intermediate substrate (nylon mesh), and coat the PET film coated with polysiloxane on the same Between the gaps, the liquid is evenly squeezed and unfolded, and the thickness is fixed to 0.75 mm. Then, a metal halide lamp was used to irradiate ultraviolet rays with an ultraviolet irradiation amount of 3000 mJ/cm ^{2 to} obtain the hydrogel of Example 1.

The hydrogels of Examples 2 to 12 were prepared in the same manner as in Example 1 except that the weight% of each component, the ultraviolet irradiation amount, or both were changed to those shown in Table 1, to produce a hydrogel.

The hydrogels of Comparative Examples 1 to 6 were prepared in the same manner as in Example 1 except that the weight% of each component, the ultraviolet irradiation amount, or both were changed to those shown in Table 1, to produce a hydrogel.

2. Various evaluation methods

The obtained hydrogels of Examples 1 to 12 and Comparative Examples 1 to 6 were evaluated by the following items.

(1) Evaluation of the adhesion of the backlight

The hydrogel was cut into 120 mm×20 mm, the gel surface that appeared after peeling off the PET film was attached to the backlight plate, and a 2 kg pressure bonding roller was pressed back and forth once to make a test piece. A rheometer (manufactured by Sun Science Co., Ltd., CR-500DX) was used for the measurement in accordance with JIS-Z0237; 2009. The measurement conditions were at an angle of 90 degrees and a speed of 300 mm/minute. Measure the stress value (N/20mm) at the time point (30, 40, 50, 60, 70mm) from the measurement start point to the predetermined peeling point, calculate the average value from the value of 3 tests (15 points in total), and use this value As the adhesion of hydrogel to the backlight. The measurement environment was carried out in an environment with a temperature of 23°C and a humidity of 55%.

(2) Evaluation of viscoelastic properties

之SUS製平行板貼合25

之凝膠片，壓抵 至成為1N之荷重點為止後，以0.1Hz測定儲存彈性模數及損失彈性模數，從其值算出損失正切(tanδ)。儲存彈性模數愈高，表示彈性之硬度愈硬的指標。 The storage elastic modulus, loss elastic modulus, and loss direct connection (tanδ) of the hydrogel were measured. Specifically, using a viscoelasticity measuring device (manufactured by Anton-Paar Corporation, MR-102), a viscoelasticity measurement of 23%, a deformation amount of 1% at a frequency of 0.1 Hz was performed. Fixture tied at 25

SUS parallel plate bonding 25

After the gel sheet was pressed until it became the load point of 1 N, the storage elastic modulus and the loss elastic modulus were measured at 0.1 Hz, and the loss tangent (tan δ) was calculated from the value. The higher the storage elastic modulus, the index indicating the hardness of the elasticity.

(3) Determination of acrylic monomers

50 mg of the sample was weighed in a test tube, and 10 mL of 2.5% phosphoric acid aqueous solution was added to dissolve it, and the foregoing content was passed through a filter and filtered. Further, the content of acrylamide monomer dissolved in the obtained filtrate was measured by high-performance liquid chromatography (HPLC).

[Determination of HPLC]

Device: HPLC LC-module 1 manufactured by Waters Corporation

Column: Tosoh Co., Ltd., SCX catalog No: 07156

Column temperature: room temperature

Dissolution solution: 0.1% phosphoric acid aqueous solution

Flow rate: 1.0mL/min

Injection volume: 30μL

Detection wavelength: 210nm

(4) Skin irritation assessment

For the 10 subjects (5 males and 5 females), the following evaluation was performed in an environment with a temperature of 23°C and a humidity of 55%. The hydrogel was cut into 120 mm×20 mm, the gel surface revealed by peeling off the PET film was attached to the wrist of the subject, and the state of the skin surface was visually observed at a time point of 6 hours. The result of the evaluation is to set "No Redness" to "Pass" and "More than 1 Redness" to "Fail".

3. Results

The results are shown in Table 1. The hydrogels of Examples 1 to 12 did not undergo any polymerization reaction at the time of manufacture, and acrylamide monomer remained. In the hydrogels of Comparative Examples 1, 3, and 5, the amount of the polymerization initiator in the monomer preparation solution was set to 0.13% by weight, the ultraviolet irradiation amount was 3000 mJ/cm ² , and the reaction rate of the polymerization reaction was 100%, remaining The monomer amount is 0%. In the hydrogels of Comparative Examples 2, 4, and 6, the amount of the polymerization initiator in the monomer preparation solution was 0.030% by weight, and the ultraviolet irradiation amount was 800 mJ/cm ² , which was the same as the preparation component and the preparation amount of the component The same hydrogels of Examples 1 to 2, Examples 5 to 6, and Examples 9 to 10 are respectively compared, the reaction rate is low, and the amount of residual monomer is large.

The hydrogels of Comparative Examples 1, 3, and 5 were the same as the formulation ingredients and the formulation amounts of the ingredients were also the same. The hydrogels of Examples 3 to 4, Examples 7 to 8, and Examples 11 to 12 were compared and stored respectively The modulus of elasticity decreases.

The hydrogels of Comparative Examples 2, 4, and 6 are the same as the formulation ingredients and the formulation amounts of the ingredients are also the same. The hydrogels of Examples 1 to 2, Examples 5 to 6, and Examples 9 to 10 are compared, respectively The force is reduced.

The skin irritation evaluation of any of the hydrogels of Examples 1 to 12 was good.

From the above results, it is shown that the hydrogel of the present invention has both high adhesion and high storage elastic modulus.

[Table l]

1‧‧‧gel tablets

10‧‧‧gel material

12‧‧‧Intermediate

14‧‧‧ basement membrane

16‧‧‧Top film

Claims (8)

A hydrogel having a polymer matrix made by polymerizing acrylic monomers, acrylic monomers, water and polyol, wherein the content of acrylic monomers is 100 to 2000 ppm. The hydrogel as described in item 1 of the patent application, wherein the acrylic monomer is an acrylic monomer. As in the hydrogel described in item 1 of the patent application scope, the hydrogel is embedded with an intermediate substrate along the in-plane direction. The hydrogel as described in item 3 of the patent application, wherein the intermediate substrate is a non-woven fabric. The hydrogel as described in item 1 of the patent application range, wherein the storage elastic modulus at a frequency of 0.1 Hz is 2000 to 9000 Pa. The hydrogel as described in item 1 of the patent application scope, wherein the adhesive force to the backlight plate is 1 to 15 N/20 mm. A medical electrode hydrogel, which is arranged between an electrode element composed of a conductive material and the surface of the skin and is used by a user, and is described in any of items 1 to 6 of the patent application Consists of hydrogel. A method for manufacturing a hydrogel, wherein the hydrogel has a polymer matrix obtained by polymerizing an acrylic monomer, an acrylic monomer, water, and a polyhydric alcohol, and the manufacturing method uses the acrylic monomer The response rate becomes 99.99 to 99.80%.

Images