JP6998120B2 - Bioresin composition and bioadhesive sheet - Google Patents

Description

The present invention relates to a biological resin composition and a biological adhesive sheet.

Adhesive plasters for the purpose of protecting and treating wounds, and medical products such as poultices, tapes and poultices for the purpose of anti-inflammatory and analgesia, which are used by being attached to a living body, are widely used.

Such bio-attachable medical products include a base material typified by paper, non-woven fabric, and various resin films, an adhesive layer for attaching to a living body, and a release film for protecting the adhesive layer. Often have at least.
The bio-attached medical product is used by peeling off the release film at the time of use and attaching the adhesive layer to the skin, and is peeled off from the living body after use.

Generally, the pressure-sensitive adhesive layer is formed from a water-dispersible type pressure-sensitive adhesive composition because it is less irritating to a living body than a solvent-type pressure-sensitive adhesive composition containing an organic solvent. The pressure-sensitive adhesive composition often contains a (meth) acrylic polymer as a pressure-sensitive component.
As a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer used for attachment to a living body, Patent Document 1 describes the following monomers (a) to (d) and (a) alkyl groups having 3 or less carbon atoms (a). Meta) Acrylic acid alkyl ester 40% by weight or more, (b) (B) Alkylate (meth) acrylic acid alkyl ester having 4 or more carbon atoms 30% by weight or less, (c) At least one functional group in addition to the radically polymerizable group Functional monomer having 10% by weight or less, (d) copolymerizable with the above-mentioned monomers (a) to (c), and a co-monomer 55 other than the monomers (a) to (c) It is an acrylic (co) polymer obtained by (co) polymerization of% by weight or less [however, the total of the monomers (a) to (d) is 100% by weight], and the glass transition point thereof is A medical pressure-sensitive adhesive composition containing an acrylic (co) polymer in the range of + 10 ° C. or lower is described.

Japanese Unexamined Patent Publication No. 9-132525

When the release film is peeled off when the medical product is attached to a living body, for example, the adhesive layers may stick to each other and cannot be attached to the living body, or wrinkles may occur. In recent years, the sticking area of a biological sticking type medical product has become large, and such a defect has become a more problematic. Therefore, it is required to have a property that such a problem is less likely to occur, that is, to be excellent in ease of handling, as compared with the conventional case.

Further, the living body-attached medical product is required to prevent unintentional withdrawal from the living body for a required period such as 8 hours, that is, to have excellent retention.

In general, a pressure-sensitive adhesive layer having excellent handleability tends to have low adhesive strength and poor retention. Further, the pressure-sensitive adhesive layer having excellent retention tends to have high adhesive strength and is inferior in ease of handling. As described above, it is considered that the ease of handling and the holdability are contradictory to each other.
As a result of examination by the inventors, the pressure-sensitive adhesive composition described in Patent Document 1 may not have sufficient ease of handling and / or retention.

The present invention has been made in view of the above, and is a bioresinic resin composition capable of forming a pressure-sensitive adhesive layer excellent in ease of handling and retention, and a pressure-sensitive adhesive formed from a composition containing the resin composition. An object of the present invention is to provide a biological adhesive sheet containing a layer.

The means for solving the above problems include the following embodiments.
<1> The constituent unit A derived from the (meth) acrylic acid alkyl ester having a glass transition temperature of 0 ° C. or higher when homopolymerized is 50% by mass to 94.5% by mass with respect to all the constituent units.
The constituent unit B derived from the (meth) acrylic acid alkyl ester having a glass transition temperature of -50 ° C or lower when homopolymerized is 5% by mass to 49.5% by mass with respect to all the constituent units.
A (meth) acrylic polymer containing 0.5% by mass to 10% by mass of a structural unit C derived from a monomer having a carboxy group with respect to all the structural units.
A biological resin composition comprising a surfactant.
<2> The biological resin composition according to <1>, wherein the (meth) acrylic polymer has a glass transition temperature of −30 ° C. to 0 ° C.
<3> The biological resin composition according to <1> or <2>, wherein the structural unit A contains a structural unit derived from methyl acrylate.
<4> The biological resin composition according to any one of <1> to <3>, wherein the structural unit B contains a structural unit derived from 2-ethylhexyl acrylate.
<5> A biological pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer formed from the composition containing the biological resin composition according to any one of <1> to <4>.

According to the present invention, a biological resin composition capable of forming a pressure-sensitive adhesive layer having excellent handleability and retention, and a biological pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer formed from a composition containing the resin composition. Can be provided.

Hereinafter, embodiments that are an example of the present invention will be described.
In the present specification, the numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively. Further, in the present specification, the amount of each component in the composition is the amount of the plurality of substances corresponding to the components, unless otherwise specified, when a plurality of substances corresponding to the components are used in combination in the composition. Means the total amount.
(Meta) acrylic means at least one of acrylic and methacrylic, and (meth) acrylate means at least one of acrylate and methacrylate.
The biological resin composition means a pressure-sensitive adhesive sheet used by being attached to a living body, that is, a resin composition used for forming a so-called biological pressure-sensitive adhesive sheet.
The biological pressure-sensitive adhesive layer means a pressure-sensitive adhesive layer that is used by being attached to a living body.

<< Biological resin composition >>
In the bioresin composition of the present invention, the constituent unit A derived from the (meth) acrylic acid alkyl ester having a glass transition temperature of 0 ° C. or higher when homopolymerized is 50% by mass to 94% based on all the constituent units. The constituent unit B derived from the (meth) acrylic acid alkyl ester, which has a glass transition temperature of -50 ° C or lower when homopolymerized, is 5% by mass to 49.5% by mass with respect to all the constituent units. %, A (meth) acrylic polymer containing 0.5% by mass to 10% by mass of a structural unit C derived from a monomer having a carboxy group, and a surfactant. ..

The pressure-sensitive adhesive layer formed from the composition containing the biological resin composition of the present invention is excellent in ease of handling and retention.
The reason for this is not clear, but the inventors speculate as follows.
The (meth) acrylic polymer contained in the biological resin composition of the present invention contains a structural unit A derived from a (meth) acrylic acid alkyl ester having a high glass transition temperature and an alkyl (meth) acrylic acid having a low glass transition temperature. It contains a structural unit B derived from an ester and a structural unit C derived from a monomer having a carboxy group.
Of these, the structural unit A, which has a high glass transition temperature derived from the (meth) acrylic acid alkyl ester, partially hardens the (meth) acrylic polymer, reduces sticking between the pressure-sensitive adhesive layers, and is easy to handle. Is considered to be granted. Further, the structural unit B derived from the (meth) acrylic acid alkyl ester having a low glass transition temperature partially softens the (meth) acrylic polymer, improves the adhesion to the living body as an adherend, and retains it. It is thought to give sex. Further, the structural unit C derived from the monomer having a carboxy group imparts polarity to the (meth) acrylic polymer, contributes to the formation of stable emulsified particles together with the surfactant, and contributes to easy sticking and retention. Conceivable.
Since the biological resin composition of the present invention contains each of these constituent units in a predetermined ratio, it is considered that the contradictory ease of handling and retention can be achieved at the same time.

<(Meta) acrylic polymer>
The (meth) acrylic polymer contained in the biological resin composition of the present invention comprises all the constituent units A derived from the (meth) acrylic acid alkyl ester having a glass transition temperature of 0 ° C. or higher when homopolymerized. Constituent unit B derived from (meth) acrylic acid alkyl ester having a glass transition temperature of -50 ° C or lower when homopolymerized, which is 50% by mass to 94.5% by mass with respect to the unit, is added to all the constituent units. It contains 5% by mass to 49.5% by mass and 0.5% by mass to 10% by mass of the structural unit C derived from the monomer having a carboxy group with respect to all the structural units.

[Structure unit A]
The structural unit A in the (meth) acrylic polymer contained in the biological resin composition of the present invention is a structural unit derived from a (meth) acrylic acid alkyl ester having a glass transition temperature of 0 ° C. or higher when homopolymerized. Is.

Examples of the (meth) acrylic acid alkyl ester having a glass transition temperature of 0 ° C. or higher when homopolymerized are methyl acrylate (5 ° C.), lauryl acrylate (15 ° C.), stearyl acrylate (30 ° C.), and methyl methacrylate. (103 ° C.), ethyl methacrylate (42 ° C.), n-butyl methacrylate (21 ° C.), isobutyl methacrylate (48 ° C.), tert-butyl methacrylate, stearyl methacrylate (36 ° C.) and isostearyl methacrylate (30 ° C.). ..
Among these, the (meth) acrylic acid alkyl ester having a glass transition temperature of 0 ° C. or higher when homopolymerized is composed of methyl acrylate, n-butyl methacrylate and methyl methacrylate from the viewpoint of further improving the ease of handling. One or more selected from the group is preferable, and methyl acrylate is more preferable.
The parentheses attached after each (meth) acrylic acid alkyl ester are the glass transition temperature when each (meth) acrylic acid alkyl ester is used as a homopolymer.

The content of the structural unit A in the (meth) acrylic polymer contained in the biological resin composition of the present invention is 50% by mass to 94.5% by mass with respect to all the structural units. If the content of the structural unit A is less than 50% by mass, the stickability may be inferior, and if the content of the structural unit A is more than 94.5% by mass, the tack may be low and the retention may be inferior.
The content of the structural unit A is preferably 65% by mass or more, more preferably 70% by mass or more, from the viewpoint of further improving the ease of handling. Further, the content of the constituent unit A is preferably 90% by mass or less, more preferably 87% by mass or less, from the viewpoint of further increasing the tack and further improving the holding property.

[Structure unit B]
The structural unit B of the (meth) acrylic polymer contained in the biological resin composition of the present invention is derived from a (meth) acrylic acid alkyl ester having a glass transition temperature of −50 ° C. or lower when homopolymerized. It is a unit.

Examples of the (meth) acrylic acid alkyl ester having a glass transition temperature of -50 ° C or lower when homopolymerized are n-butyl acrylate (-57 ° C), octyl acrylate (-80 ° C) and 2-ethylhexyl acrylate. (-76 ° C), lauryl methacrylate (-65 ° C) and the like.
Among these, the (meth) acrylic acid alkyl ester having a glass transition temperature of -50 ° C or lower when homopolymerized is a group consisting of n-butyl acrylate and 2-ethylhexyl acrylate from the viewpoint of further improving the retention. One or more selected from the above is preferable, and 2-ethylhexyl acrylate is more preferable.
The parentheses attached after each (meth) acrylic acid alkyl ester are the glass transition temperature when each (meth) acrylic acid alkyl ester is used as a homopolymer.

The content of the structural unit B in the (meth) acrylic polymer contained in the biological resin composition of the present invention is 5% by mass to 49.5% by mass with respect to all the structural units. If the content of the structural unit B is less than 5% by mass, the retention may be inferior, and if the content of the structural unit A is more than 49.5% by mass, the handleability may be inferior.
The content of the structural unit B is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, from the viewpoint of further improving the retention. Further, the content of the constituent unit B is preferably 45% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, from the viewpoint of further improving the ease of handling.

[Construction unit C]
The structural unit C in the (meth) acrylic polymer contained in the biological resin composition of the present invention is a structural unit derived from a monomer having a carboxy group.

Examples of the monomer having a carboxy group include (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, citraconic acid, lauric acid, 2- (meth) acryloyloxyethyl succinic acid, and maleic acid. Monohydroxyethyl (meth) acrylate, monohydroxyethyl (meth) acrylate, monohydroxyethyl (meth) phthalate, 1,2-dicarboxycyclohexane monohydroxyethyl (meth) acrylate, (meth) acrylic acid dimer And ω-carboxy-polycaprolactone mono (meth) acrylate.
Among these, as the monomer having a carboxy group, (meth) acrylic acid is preferable, and acrylic acid is more preferable, because the emulsified particles tend to be stable and easy to be applied when emulsified and polymerized.

The content of the structural unit C in the (meth) acrylic polymer contained in the biological resin composition of the present invention is 0.5% by mass to 10% by mass with respect to all the structural units. If the content of the constituent unit C is less than 0.5% by mass, the stability of the emulsified particles may be inferior, and if the content of the constituent unit C is more than 10% by mass, the tack is low and the retention property is improved. It may be inferior.
The content of the structural unit C is preferably 1% by mass or more, more preferably 1.5% by mass or more, from the viewpoint of further improving the stability of the emulsified particles. Further, the content of the structural unit A is preferably 8% by mass or less, more preferably 5% by mass or less, from the viewpoint of further increasing the tack and further improving the holding property.

[Other building blocks]
The (meth) acrylic polymer contained in the biological resin composition of the present invention may contain other structural units other than the structural unit A, the structural unit B and the structural unit C.

Examples of the monomer forming other constituent units include a (meth) acrylic acid alkyl ester having a glass transition temperature of more than -50 ° C and less than 0 ° C when homopolymer is used, an aromatic monovinyl compound, and a monomer having a methylol group. , A monomer having a hydroxyl group, a monomer having a glycidyl group, a monomer having an amide group, and a monomer having a tertiary amino group.

Examples of the (meth) acrylic acid alkyl ester having a glass transition temperature of more than -50 ° C and less than 0 ° C when homopolymerized are ethyl acrylate (-27 ° C), isoamyl acrylate (-45 ° C), and isostearyl acrylate. (-18 ° C), 2-ethylhexyl methacrylate (-10 ° C), tridecyl methacrylate (-40 ° C), isooctyl methacrylate (-30 ° C), isononyl methacrylate (-30 ° C) and isodecyl methacrylate (-41 ° C). ).
The parentheses attached after each (meth) acrylic acid alkyl ester are the glass transition temperature when each (meth) acrylic acid alkyl ester is used as a homopolymer.

Examples of the aromatic monovinyl compound include styrene, α-methylstyrene, t-butylstyrene, p-chlorostyrene, chloromethylstyrene and vinyltoluene.

Examples of the monomer having a methylol group include N-methylolacrylamide, N-methylolmethacrylamide, dimethylolacrylamide, dimethylolmethacrylamide, N-butylolacrylamide and N-butylolmethacrylamide.

Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 6-hydroxyhexyl ( Examples include meth) acrylates, 10-hydroxydecyl (meth) acrylates, 12-hydroxylauryl (meth) acrylates and 3-methyl-3-hydroxybutyl (meth) acrylates.

Examples of the monomer having a glycidyl group include glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, glycidyl vinyl ether, 3,4-epoxycyclohexylvinyl ether, glycidyl (meth) allyl ether and 3,4-. Epoxycyclohexyl (meth) allyl ethers can be mentioned.

Examples of the monomer having an amide group include acrylamide, methacrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, and N. -Propoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-tert-butyl acrylamide, N-octyl acrylamide and diacetone acrylamide.

Examples of the monomer having a tertiary amino group include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylamide.

The content of other structural units in the (meth) acrylic polymer is preferably 20% by mass or less, more preferably 10% by mass or less, based on all the structural units, from the viewpoint of further improving ease of handling and retention. It is more preferably 1% by mass or less, particularly preferably 0.1% by mass or less, and most preferably not contained.

[Glass-transition temperature]
The glass transition temperature of the (meth) acrylic polymer contained in the biological resin composition of the present invention is preferably −30 ° C. to 0 ° C., preferably −25 ° C. to 0 ° C. from the viewpoint of further improving handleability and retention. −5 ° C. is more preferable, and −20 ° C. to −8 ° C. is further preferable.

The glass transition temperature (Tg) of the (meth) acrylic polymer in the present invention is a value obtained by converting the absolute temperature (K) obtained by the calculation of the following formula into the Celsius temperature (° C.).

In the formula, Tg ₁ , Tg ₂ , ... And Tg _n are represented by the absolute temperature (K) when each of the monomers of monomer 1, monomer 2, ... and monomer n is homopolymer. The glass transition temperature to be achieved. m ₁ , m ₂ , ... And _mn are mass fractions of the respective monomers.
The "glass transition temperature represented by the absolute temperature (K) when homopolymerized" is the glass transition temperature represented by the absolute temperature (K) of the homopolymer produced by polymerizing the monomer alone. say.
The glass transition temperature of the homopolymer is set under the conditions of a differential scanning calorimetry device (DSC) (EXSTAR6000, manufactured by Seiko Instruments), a measurement sample of 10 mg, and a temperature rise rate of 10 ° C./min. The measurement was carried out, and the change point of the obtained DSC curve was taken as the glass transition temperature of the homopolymer.

[Synthesis method]
The method for synthesizing the (meth) acrylic polymer contained in the biological resin composition of the present invention is not particularly limited. The (meth) acrylic polymer can be synthesized by polymerizing a monomer by a method such as solution polymerization, emulsion polymerization, or suspension polymerization.
The biological resin composition of the present invention is preferably a water-dispersed type from the viewpoint of adjusting the viscosity so that it is easy to apply without using an organic solvent and reducing irritation to the living body when it is used as a biological pressure-sensitive adhesive layer. .. Emulsion polymerization is preferable as a method for synthesizing a (meth) acrylic polymer from the viewpoint of producing a water-dispersible bioresin composition with fewer treatment steps.

In emulsion polymerization, in general, a predetermined aqueous medium, a monomer, a polymerization initiator, and raw materials such as a reducing agent and a chain transfer agent used as needed are charged in a polymerization tank, and the number is stirred, for example, in a nitrogen stream. Heat reaction for time.
The raw materials may be charged in a polymerization tank all at once or sequentially.

Examples of the polymerization initiator used for emulsifying polymerization include persulfates typified by potassium persulfate, ammonium persulfate and sodium persulfate, azobisisobutyronitrile, and azobis-4-methoxy-2,4-dimethyl. Valeronitrile, azobiscyclohexanone-1-carbonitrile, azodibenzoyl, azo compounds typified by 4,4'-azobis (4-cyanovalerian acid), benzoyl peroxide, lauroyl peroxide, di-t-butyl Peroxyhexahydroterephthalate, t-butylperoxy-2-ethylhexanoate, 1,1-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butylperoxyisopropylcarbonate, t-butylhydro Examples thereof include organic peroxides typified by peroxide, cumenehydroperoxide, t-butylperoxypivalate and t-hexylperoxypivalate.
The amount of the polymerization initiator used in the emulsion polymerization is preferably 0.01 part by mass to 5 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the total amount of the monomers constituting the (meth) acrylic polymer. 1 part by mass is more preferable.

Examples of the reducing agent used for emulsifying polymerization include sodium bisulfite, sodium metabisulfite, sodium sulfite, sodium pyrophosphate, thioglycolic acid, sodium thiosulfite, potassium bisulfite, ammonium bisulfite, ferrous chloride, and longalit. , Thiourea dioxide, ascorbic acid, tartrate acid, citric acid and glucose.
When a reducing agent is used in the emulsion polymerization, the amount of the reducing agent is preferably 0.001 part by mass to 5 parts by mass with respect to 100 parts by mass of the total amount of the monomers constituting the (meth) acrylic polymer. More preferably, it is 0.01 part by mass to 0.1 part by mass.

Examples of the chain transfer agent used for emulsion polymerization include mercaptan compounds typified by alkyl mercaptan, thioglycol and 2-mercaptopropionic acid, and allyl compounds typified by allyl acetate, α-methylstyrene dimer and allyl carbinol. Can be mentioned.
When a chain transfer agent is used in the emulsion polymerization, the amount of the chain transfer agent is preferably 0.01 part by mass to 5 parts by mass with respect to 100 parts by mass of the total amount of the monomers constituting the (meth) acrylic polymer. , 0.1 to 1 part by mass is more preferable.

<Surfactant>
The biological resin composition of the present invention contains a surfactant. The surfactant contained in the biological resin composition of the present invention has a hydrophobic group and a hydrophilic group in the same molecule.
The surfactant contained in the biological resin composition of the present invention is an ordinary surfactant used for emulsion polymerization. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. These surfactants may be used alone or in combination of two or more.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers represented by polyoxyethylene lauryl ether and polyoxyethylene stearyl ether, and polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether. Polyoxyethylene alkylphenyl ethers, sorbitan higher fatty acid esters typified by sorbitan monolaurate, sorbitan monostearate and sorbitan trioleate, and polyoxyethylene sorbitan higher fatty acids typified by polyoxyethylene sorbitan monolaurate. Esters, polyoxyethylene higher fatty acid esters represented by polyoxyethylene monolaurate and polyoxyethylene monostearate, glycerin higher fatty acid esters represented by oleic acid monoglyceride and stearate monoglyceride, and polyoxy Examples include ethylene-polyoxypropylene-block copolymers.

Examples of anionic surfactants include higher fatty acid salts represented by sodium oleate, alkylaryl sulfonates represented by sodium dodecylbenzene sulfonate, alkyl sulfate ester salts represented by sodium lauryl sulfate, and the like. , Polyoxyethylene alkyl ether sulfates represented by polyoxyethylene lauryl ether sodium sulfate, polyoxyethylene alkylaryl ether sulfates represented by polyoxyethylene nonylphenyl ether sulfate, and sodium monooctylsulfosuccinate. , Alkyl sulfosuccinic acid ester salts typified by sodium dioctyl sulfosuccinate and sodium polyoxyethylene lauryl sulfosuccinate, and derivatives thereof.

Examples of cationic surfactants include alkylamine salts typified by laurylamine acetate, quaternary ammonium salts typified by lauryltrimethylammonium chloride and alkylbenzyldimethylammonium chloride, and polyoxyethylalkylamines. Be done.

Examples of amphoteric surfactants include alkyl betaine typified by lauryl betaine.

Further, so-called reactive surfactants having a copolymerizable unsaturated group in the molecular structure can also be preferably used.

The surfactant contained in the biological resin composition of the present invention has a sufficient track record in the biological resin composition and is less irritating to the living body. Therefore, ethylene is in the range of 10 mol to 100 mol, preferably in the range of 20 mol to 70 mol. Polyoxyethylene alkyl phenyl ether having an oxide chain in the molecule is preferable.

Such surfactants are polyoxyethylene nonylphenyl ethers manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade names Neugen EM-230D Neugen EM-250, and Aoki Yushi Kogyo Co., Ltd., trade names BRANON N-520, N-550, Product names Nonion NS-230 and NS-270 manufactured by NOF CORPORATION are commercially available.

The content of the surfactant in the biological resin composition of the present invention is preferably 0.5 parts by mass to 20 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer from the viewpoint of making the emulsified particles more stable. 1 part by mass to 10 parts by mass is more preferable, and 2 parts by mass to 6 parts by mass is further preferable.

[Aqueous medium]
The biological resin composition of the present invention is water-dispersible from the viewpoint of adjusting the viscosity to be easy to apply without using an organic solvent and reducing irritation to the living body when it is used as a biological pressure-sensitive adhesive layer. Is preferable. Therefore, the biological resin composition of the present invention preferably contains an aqueous medium.
The aqueous medium is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of the aqueous medium include water and a mixed solution of water and an alcohol solvent. From the viewpoint of the stability of the emulsified particles, water is preferable as the aqueous medium.
Examples of the alcohol solvent include methyl alcohol, ethyl alcohol and propyl alcohol.
The biological resin composition of the present invention preferably contains an aqueous medium from the viewpoint of work efficiency.
When the biological resin composition of the present invention contains an aqueous medium, the (meth) acrylic polymer can be dispersed in the aqueous medium by a surfactant to form emulsified particles.

The content of the aqueous medium in the biological resin composition of the present invention is not particularly limited, and is preferably 10.0% by mass to 70.0% by mass, preferably 20.0% by mass, based on the total mass of the biological resin composition. % To 60.0% by mass is more preferable, and 30.0% by mass to 50.0% by mass is further preferable.

<Other additives>
The biological resin composition of the present invention contains various agents, thickeners, wetting agents (moisturizers), fillers (excipients), absorption promoters, preservatives, as long as the excellent effects of the present invention are not impaired. It may contain antioxidants, other stabilizers, pigments, dyes, tackifiers and inorganic fillers. Further, a (meth) acrylic resin other than the above (meth) acrylic polymer and a (meth) acrylic oligomer may be contained.

The biological resin composition of the present invention can be applied to a so-called transdermal absorption preparation by containing various drugs. Such various drugs include, for example, coronary vasodilators, anti-arrhythmic agents, angina, hypotensive agents, cardiotonic agents, bronchial asthma agents (bronchial dilators), antihypertensive agents, calcium channel blockers, anti-inflammatory analgesics, skin. Disease agents, local anesthetics, antihypertensive diuretics, hypnotic sedatives, central nervous system agents, psychoactive agents, hormone agents, sulfa agents, antituberculous agents, antihistamines, antiallergic agents and analgesics.

Examples of the thickener include synthetic water-soluble polymers typified by sodium polyacrylate, polyacrylic acid, polyvinyl alcohol and polyvinylpyrrolidone, and natural polymers typified by Na carboxymethyl cellulose, methyl cellulose and hydroxymethyl cellulose. Examples thereof include derivatives and natural polymers typified by starch and gelatin.

Examples of the wetting agent (moisturizer) include polyhydric alcohols typified by glycerin, propylene glycol, 1,3-butylene glycol and sorbitol.

Examples of the filler (excipient) include inorganic substances typified by kaolin, zinc oxide, titanium oxide, talc, bentonite, hydrous aluminum silicate and magnesium aluminometasilicate.

Examples of the absorption accelerator include monohydric alcohols typified by pentanol, hexanol, octanol, decanol and benzyl alcohol, and typified by polyethylene glycol, propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol and glycerin. Examples thereof include polyhydric alcohols, fatty acids typified by isostearic acid and lauric acid, and fatty acid esters typified by isopropyl myristate, octyldodecyl myristate and isopropyl palmitate.
The polyhydric alcohols can be used both as a wetting agent (excipient) and as an absorption promoter.

Examples of preservatives, antioxidants, and other stabilizers include timol, methyl paraoxybenzoate (methylparaben), ethyl paraoxybenzoate (ethylparaben), ascorbic acid, butylhydroxyanisole, dibutylhydroxytoluene, and vitamin E. , Disodium edetate and tartrate acid.

<Use>
The biological resin composition of the present invention can be used, for example, as a pressure-sensitive adhesive composition for producing a biological pressure-sensitive adhesive sheet. In addition, the biological resin composition of the present invention can also be used as an auxiliary agent for adjusting the adhesive strength in the pressure-sensitive adhesive composition for producing a biological pressure-sensitive adhesive sheet.

<< Adhesive sheet >>
The biological pressure-sensitive adhesive sheet of the present invention contains at least a pressure-sensitive adhesive layer formed from a composition containing the biological resin composition of the present invention.
The biological pressure-sensitive adhesive sheet of the present invention preferably further contains a base material. Examples of the base material include paper, non-woven fabric, and resin film.
The "composition containing the biological resin composition of the present invention" includes only the biological resin composition of the present invention, that is, the biological resin composition itself of the present invention or the biological resin of the present invention. It means a composition containing the composition as an auxiliary agent.

The method for producing a biological pressure-sensitive adhesive sheet of the present invention is not particularly limited.
For example, the biological resin composition of the present invention or the composition containing the biological resin composition of the present invention is applied directly on the substrate or via another layer and dried to form a pressure-sensitive adhesive layer. The bioadhesive sheet of the present invention can be produced.
The method of application is not particularly limited, and examples thereof include known methods using a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, and a spray coater.

<Application example>
The bioadhesive sheet of the present invention can be used, for example, as an adhesive plaster, a dressing material, or a drape material.
In addition, the bioadhesive sheet of the present invention can also be applied to patches, poultices, tapes, and poultices called transdermal absorption preparations.
In addition, the bio-adhesive sheet of the present invention includes facial masks, eyelashes, facial masks, facial masks, body seals and tattoo seals that are temporarily attached to the human body, lift-up tape that makes wrinkles and sagging of the face less noticeable, and double. It can also be applied to eye tapes that correct the eyelids and face masks for face packs.
Further, the biological adhesive sheet of the present invention can also be applied to an electrode (biological electrode) provided in a medical device used for various treatments and examinations.
Furthermore, the adhesive sheet for living organisms of the present invention can be applied not only to the human body but also to pet animals such as dogs, cats and rabbits.

Hereinafter, the present invention will be described in more detail with reference to Examples. The present invention is not limited to the following examples as long as the gist is not exceeded.

[Example 1]
-Preparation of water-dispersible bio-resin composition-
5. 20 parts by mass of deionized water in a stirring container equipped with a stirrer, polyoxyethylene nonylphenyl ether as a surfactant (trade name Neugen EM-230D manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: active ingredient concentration 70% by mass). Methyl acrylate (MA) acrylic acid alkyl ester having a glass transition temperature of 0 ° C. or higher when 7 parts by mass (active ingredient: 4 parts by mass) is charged, stirred and dissolved, and then homopolymer is used. ) 73.5 parts by mass, 24.5 parts by mass of n-butyl acrylate (BA) which is a (meth) acrylic acid alkyl ester having a glass transition temperature of −50 ° C. or lower when homopolymerized, and a carboxy group. A monomer mixture consisting of 2.0 parts by mass of acrylic acid (AA), which is a monomer having a monomer, was added and stirred to obtain a monomer premix.
30 parts by mass of deionized water is charged in a reaction vessel equipped with a thermometer, a stirrer, and a reflux cooler, and heated while stirring under a nitrogen stream. When the water temperature in the reaction vessel reaches 70 ° C., it is used as a reducing agent. After 0.03 part by mass of sodium bisulfite was added, 20 parts by mass of a 2% potassium persulfate aqueous solution (active ingredient: 0.4 parts by mass) and a monomer premix were sequentially added as a polymerization initiator to initiate polymerization. A polymerization reaction was carried out for 5 hours to synthesize a (meth) acrylic polymer. After completion of the polymerization reaction, stirring was continued at the same temperature for about 2 hours and then cooled to obtain a water-dispersed bioresin composition. The pH of the obtained water-dispersed bio-resin composition was 2.2, the viscosity (measured at 12 rpm, 25 ° C., BL type viscometer) was 130 mPa · s, and the solid content was 59.0. %Met. Further, when the Tg of the (meth) acrylic polymer was calculated by the method described above, it was -11.5 ° C.

-Preparation of evaluation test pieces-
A water-dispersible bioresin composition is coated on a release paper (trade name G7B-J manufactured by Oji Tac Co., Ltd.) so that the weight after drying is in the range of 70 to 90 g / m ² , and at 100 ° C. After heating and drying for 10 minutes, it is bonded to a non-woven fabric (trade name Oikos AP20600400 manufactured by Nisshin Spinning Co., Ltd.), and is an evaluation test which is a biological adhesive sheet having an adhesive layer formed from a composition containing a biological resin composition. It was a piece. The size of the evaluation test piece is 15 cm square. The following items were evaluated using this evaluation test piece. The evaluation results are shown in Table 1.

-Evaluation of retention-
The evaluation test piece prepared above was attached to human skin and held for 8 hours, and the presence or absence of peeling was visually confirmed. It was evaluated according to the following evaluation criteria.
<Evaluation criteria for retention>
A: There is no peeling and it has excellent retention.
B: It has peeled off and is inferior in retention.

-Evaluation of ease of handling-
The evaluation test pieces prepared above were scored according to the following scoring criteria from the viewpoint of sticking of the adhesive layer and occurrence of wrinkles on the workability from peeling off the release paper to sticking to the skin. The number of monitors was 10, and the average value of the scoring results of 10 monitors was evaluated according to the following evaluation criteria to obtain the evaluation result of ease of handling.
<Scoring criteria>
5 points: Very easy to paste.
4 points: Easy to paste.
3 points: Slightly easy to paste.
2 points: Slightly difficult to paste.
1 point: Difficult to paste.
<Evaluation criteria for ease of handling>
A: 4 points or more; very excellent in ease of handling.
B: 3 points or more and less than 4 points; excellent in ease of handling.
C: Less than 3 points; inferior in ease of handling.

[Examples 2 to 8, Comparative Examples 1 to 5]
A biological resin composition and an evaluation test piece were prepared and prepared in the same manner as in Example 1 except that the compositions of the monomer and the surfactant in the (meth) acrylic polymer were changed as shown in Table 1. evaluated. Table 1 shows the glass transition temperature of the (meth) acrylic polymer calculated by the method described above and the evaluation results.

The abbreviations in Table 1 are as follows.
MA: Methyl acrylate BMA: n-butyl methacrylate MMA: Methyl methacrylate 2 EHA: 2-ethylhexyl acrylate BA: n-butyl acrylate AA: Acrylic acid EA: Ethyl acrylate EM-230D: Trade name Neugen EM-230D (Daiichi Kogyo Seiyaku Co., Ltd.) Made by the company, polyoxyethylene nonylphenyl ether, surfactant)
EM-250: Product name Neugen EM-250 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., polyoxyethylene nonylphenyl ether, surfactant)
NS-270: Product name Nonion NS-270 (manufactured by NOF CORPORATION, polyoxyethylene nonylphenyl ether, surfactant)
In addition, "-" means that the corresponding substance is not contained.
The parentheses after the abbreviation of the monomer are the glass transition temperature when the monomer is homopolymer.
In addition, each number of parts by mass is an active ingredient or a solid content conversion value.

As shown in Table 1, the evaluation test piece, which is a biological pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from the composition containing the biological resin composition of each example, is excellent in ease of handling and retention. You can see that.
On the other hand, Comparative Example 1 and Comparative Example 2 in which the content of the constituent unit A is less than 50% by mass and the content of the constituent unit B is more than 49.5% by mass with respect to all the constituent units are easy to handle. It was inferior in sex. Comparative Example 3 not including the structural unit B was inferior in retention. Comparative Example 4 in which the content of the constituent unit A was less than 50% by mass with respect to all the constituent units and did not include the constituent unit B was inferior in retention. In Comparative Example 5 in which the content of the structural unit C exceeded 10% by mass, the tack was low and the retention was inferior.

Claims (5)

The constituent unit A derived from the (meth) acrylic acid alkyl ester having a glass transition temperature of 0 ° C. or higher when homopolymerized is 50% by mass to 94.5% by mass with respect to all the constituent units.
The constituent unit B derived from the (meth) acrylic acid alkyl ester having a glass transition temperature of -50 ° C or lower when homopolymerized is 5% by mass to 49.5% by mass with respect to all the constituent units.
A (meth) acrylic polymer containing 0.5% by mass to 2% by mass of a structural unit C derived from a monomer having a carboxy group with respect to all the structural units.
Water containing 2% by mass to 6% by mass of polyoxyethylene nonylphenyl ether having an ethylene oxide chain in the range of 20 mol to 70 mol as a surfactant with respect to 100% by mass of the (meth) acrylic polymer. Dispersion type bioresin composition. The biological resin composition according to claim 1, wherein the (meth) acrylic polymer has a glass transition temperature of −30 ° C. to 0 ° C. The biological resin composition according to claim 1 or 2, wherein the structural unit A contains a structural unit derived from methyl acrylate. The biological resin composition according to any one of claims 1 to 3, wherein the structural unit B contains a structural unit derived from 2-ethylhexyl acrylate. A biological pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer formed from a composition containing the biological resin composition according to any one of claims 1 to 4.