JPH08253756A - Pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE: To obtain a pressure-sensitive adhesive composition having excellent stick in virtue of a good balance between pressure-sensitive adhesiveness and cohesive force and not undergoing a long-term change in solution viscosity. CONSTITUTION: The composition comprises a solid component comprising a pressure-sensitive adhesive insoluble in water and soluble in an organic solvent comprising a lower alcohol or a mixture thereof and the organic solvent. The organic solvent should be contained in an amount of at least 30 pts.wt. or above per 100 pts.wt. solid component. the solid component should be contained in an amount of 5wt.% or above based on the composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an adhesive composition.

[0002]

2. Description of the Related Art Generally, the conditions required for an adhesive composition and an adhesive tape using the same are: (1) reliably adhering to the skin or the like with an appropriate adhesive force for a predetermined time,
(2) No adhesive residue or stringing occurs when the adhesive tape is peeled off, and (3) easy manufacture without requiring special equipment.

Conventionally, in the pressure-sensitive adhesive tape, a method of crosslinking the pressure-sensitive adhesive has been used in order to impart an appropriate cohesive force. Examples of the cross-linking method include a method of slightly cross-linking the pressure-sensitive adhesive itself with a cross-linking agent or the like; a method of forming a pressure-sensitive adhesive layer on a support or the like, and then performing metal ion cross-linking, urethane cross-linking, epoxy cross-linking, melamine cross-linking; After forming a pressure-sensitive adhesive layer on the above, a method of causing a radical reaction by peroxide or electron beam irradiation to crosslink, and the like can be mentioned. However, with such a crosslinking method, the cohesive force of the obtained pressure-sensitive adhesive layer is improved, but on the other hand, there is a problem that the adhesive force is lowered and the sticking property is deteriorated.

In addition, the adhesive layer comprises an adhesive base, a plasticizer,
A patch comprising silicic acid anhydride and a drug is disclosed in JP-A-3-291.
No. 218, gazette. In this patch, the cohesive force of the pressure-sensitive adhesive layer can be increased by adding silicic acid anhydride. However, in this patch, when the pressure-sensitive adhesive composition is made into an ethyl acetate solution, the solution viscosity is known to increase with time, and therefore, in mass production, the thickness accuracy of the pressure-sensitive adhesive layer varies. There was a problem that it would grow.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide an excellent sticking property due to a balance performance of an adhesive force and a cohesive force and a solution viscosity of the solution. An object is to provide a pressure-sensitive adhesive composition that does not change with time.

[0006]

[Means for Solving the Problems]

The pressure-sensitive adhesive composition of the present invention is composed of a pressure-sensitive adhesive which is insoluble in water and soluble in an organic solvent consisting of a lower alcohol alone or a mixed solvent thereof, a solid content of silicic acid anhydride, and the organic solvent. It

Examples of the water-insoluble and organic solvent-soluble pressure-sensitive adhesives include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, and silicon pressure-sensitive adhesives, with acrylic pressure-sensitive adhesives being preferred. .

Examples of the acrylic adhesive include, for example,
A polymer mainly composed of (meth) acrylic acid alkyl ester is preferably used, and it is a copolymer with a functional monomer, a polyfunctional monomer, a vinyl compound or the like which is copolymerizable with (meth) acrylic acid alkyl ester. May be.

As the above-mentioned (meth) acrylic acid alkyl ester, when the carbon number of the alkyl group is reduced, the cohesive force is improved but the adhesive force is decreased, and when the alkyl group is increased, the adhesive force is improved but the cohesive force is decreased. Those having a number of 1 to 18 are preferable, for example, methyl (meth) acrylate, (meth)
Ethyl acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
Octyl acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and the like, These may be used alone or in combination of two or more.

Examples of the functional monomer include a monomer having a hydroxyl group, a monomer having a carboxyl group, a monomer having an amide group, a monomer having an amino group, and the like.

Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate,
Hydroxyalkyl (meth) acrylate such as hydroxypropyl (meth) acrylate is preferably used.

Examples of the monomer having a carboxyl group include α, β such as (meth) acrylic acid.
-Unsaturated carboxylic acid; maleic acid monoalkyl ester such as butyl maleate; (anhydrous) maleic acid, fumaric acid, crotonic acid, etc. are preferably used.

As the above-mentioned monomer having an amide group,
For example, alkyl (meth) acrylamides such as acrylamide, dimethyl acrylamide and diethyl acrylamide; alkyl ether methylol (meth) acrylamides such as butoxymethyl acrylamide and ethoxymethyl acrylamide; and diacetone acrylamide are preferably used.

As the above-mentioned monomer having an amino group,
For example, dimethylaminoethyl acrylate is preferably used.

Examples of the polyfunctional monomer include
1,6-hexane glycol dimethacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, divinylbenzene, divinyltoluene, diallyl phthalate and the like can be mentioned.

As the vinyl compound, vinyl acetate,
Examples thereof include styrene, α-methylstyrene, N-vinyl-2-pyrrolidone, vinyl chloride, acrylonitrile, ethylene, propylene and butadiene, which may be copolymerized.

The (co) polymer mainly composed of the (meth) acrylic acid alkyl ester is usually prepared by blending the above-mentioned monomers in the presence of a polymerization initiator and carrying out solution polymerization. When performing solution polymerization, ethyl acetate or other polymerization solvent is added to a predetermined amount of various monomers, in an reactor equipped with a stirrer and a cooling reflux device, azobis,
7 in a nitrogen atmosphere in the presence of a polymerization initiator such as a peroxide type.
The reaction may be performed at 0 to 90 ° C for 8 to 40 hours. Further, the monomer may be added all at once or dividedly.

As the azobis type polymerization initiator, 2,
2-azobis-iso-butyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-
Examples thereof include azobis (2,4-dimethylvalerinitrile), and examples of the peroxide-based polymerization initiator include lauroyl peroxide, benzoyl peroxide, di (tert-butyl) peroxide, and the like.

If necessary, tackifiers, plasticizers, etc. may be added to the acrylic pressure-sensitive adhesive. Examples of the tackifier include rosin resins such as rosin, hydrogenated rosin, disproportionated rosin, and rosin ester; α-pinene,
Examples include terpene resins such as β-pinene; terpene phenol resins; petroleum resins; alkyl-phenol resins; xylene resins; coumarone resins; coumarone-indene resins.

The above-mentioned plasticizer is not particularly limited as long as it can plasticize the pressure-sensitive adhesive layer, and examples thereof include cetyl octanoate, hexyl laurate, isopropyl myristate, isopropyl palmitate, butyl stearate, stearic acid. Monohydric alcohol fatty acid esters such as octyl, octyl hydroxystearate, ethyl oleate, decyl oleate, myristyl lactate; dioctyl adipate, diethyl sebacate, dioctyl sebacate, dioctyl succinate diester; propylene glycol dicaprate, Glyceryl trioctanoate, tri (octanoic acid / decanoic acid) glyceryl, polyhydric alcohol fatty acid esters such as medium chain fatty acid triglyceride, and fatty acids corresponding to these fatty acid esters; glycerin, diglycerin Number 4 or more alkylene glycols carbon; polyethylene glycol, polyhydric alcohols
Polyalkylene glycols such as polypropylene glycol; allyl alkyl alcohols; triacetin; liquid polysaccharides; liquid cationic surfactants such as alkyltrimethylammonium choroids having 12 or more carbon atoms; polyoxyethylene alkyl ethers or esters, fatty acid diethanolamides, sorbitan alkyl esters. , Nonionic surfactants such as sorbitan polyoxyethylene alkyl ester; amphoteric surfactants such as dimethyl betaine; and liquid amino acids. Among these, it is particularly preferable to use isopropyl myristate, isopropyl palmitate, diethyl sebacate, fatty acid esters such as medium-chain fatty acid triglyceride, polyethylene glycol and triacetin.

If the amount of the above-mentioned plasticizer used increases, the cohesive strength and the adhesive strength will decrease, so 50% by weight in the adhesive composition is used.
The following is preferable, and 40% by weight or less is more preferable.

The above-mentioned rubber-based pressure-sensitive adhesive is preferably composed mainly of a rubber elastic body.
1,4-isoprene (natural rubber), styrene-isoprene-styrene block copolymer, polyisoprene, polybutene, polyisobutylene, ethylene-vinyl acetate copolymer and the like can be mentioned.

If desired, tackifiers, softeners, fillers, antioxidants, etc. may be added to the rubber-based pressure-sensitive adhesive.

As the tackifier, the above-mentioned tackifiers can be used, and the amount of the tackifier used is preferably 20 to 200 parts by weight with respect to 100 parts by weight of the rubber-based adhesive.

Examples of the softening agent include oils such as process oil, palm oil, cottonseed oil, coconut oil and castor oil; polybutene, liquid isobutylene, liquid polyacrylate, beeswax, carnauba wax, lanolin and the like.
Examples of the filler include titanium oxide and the like, and examples of the antiaging agent include butylhydroxytoluene and the like.

The silicone-based pressure-sensitive adhesive is preferably one containing polydimethylsiloxane as a main component.

As the silicic acid anhydride, hydrophilic silicic acid anhydride is mainly used. In the pressure-sensitive adhesive composition, the amount of silicic acid used is largely influenced by the components of the pressure-sensitive adhesive and the composition ratio thereof, but generally, when the amount is reduced, the effect of improving the cohesive strength of the pressure-sensitive adhesive is reduced, and when the amount is increased, the pressure-sensitive adhesive is increased. The cohesive strength of the agent is improved, but the adhesive strength is reduced.
-20 wt% is preferable, and 3-15 wt% is more preferable.

The organic solvent is composed of a lower alcohol alone or a mixed solvent thereof. As the lower alcohol, when the carbon number is 6 or more, the effect of suppressing the viscosity change over time of the pressure-sensitive adhesive composition is lost, so a linear or branched alcohol having 1 to 5 carbon atoms is preferable, for example, methyl alcohol, Examples thereof include ethyl alcohol and isopropyl alcohol. In addition, examples of the solvent used in combination with the lower alcohol in the mixed solvent include acetone and tetrahydrofuran.

In the above-mentioned pressure-sensitive adhesive composition, when the amount of the organic solvent used is small, there is no effect of suppressing the change in viscosity of the pressure-sensitive adhesive composition with time, and when it is large, the solid content concentration of the pressure-sensitive adhesive composition becomes too low. Since coating becomes difficult, the solid content of the pressure-sensitive adhesive composition is limited to 30 parts by weight or more based on 100 parts by weight.

As the solvent other than the above, for example, ethyl acetate which is a solvent for polymerizing the acrylic pressure-sensitive adhesive may be added to the pressure-sensitive adhesive composition.

A percutaneous absorption preparation is obtained by incorporating a drug into the above-mentioned pressure-sensitive adhesive composition, coating it on a support by a conventionally known method for producing a pressure-sensitive adhesive tape, and drying it to form a pressure-sensitive adhesive layer. . As a coating method for the pressure-sensitive adhesive composition, a solvent coating method, a hot melt coating method, an emulsion coating method, or the like can be used.

The thickness of the above-mentioned pressure-sensitive adhesive layer is preferably 10 to 100 μm because the adhesive force decreases as the thickness decreases.

The above-mentioned drugs include the following. Acetaminophenone, phenacetin, mefenamic acid, diclofenac sodium, flufenamic acid, aspirin, sodium salicylate, aminopyrine, alclofenac, ibuprofen, naproxen, flurpiprofen, ketoprofen, amphenac sodium, mepyrizole, indomethacin, pentazocine, piroxicam, etc. Antipyretic analgesic and anti-inflammatory drug; steroidal anti-inflammatory drugs such as hydrocortisone, triamcinolone, dexamethasone, betamethasone, and prednisolone.

Vasodilators such as diltiazem hydrochloride, pentaerythritol tetranitrate, isosorbide dinitrate, trazipyr, nicorandil, nitroglycerin, prenylamine lactate, molsidomine, amyl nitrite, tolazoline hydrochloride, nifedipine; procainamide hydrochloride, lidocaine hydrochloride,
Antiarrhythmic agents such as propranolol hydrochloride, alprenolol hydrochloride, atenolol, nadolol, metoprolol tartrate, azimarin, disopyramide, mexiletine hydrochloride;
Antihypertensive agents such as ecarazine hydrochloride, indapamide, clonidine hydrochloride, bunitrolol hydrochloride, labetalol hydrochloride, captopril, guanabenz acetate, mebutamate, betanidine sulfate.

Carbetapentane citrate, cloperastine, oxerazine tannate, cloptinol hydrochloride, clofedanol hydrochloride, noscapine hydrochloride, ephedrine hydrochloride, isoproterenol hydrochloride, chlorprenaline hydrochloride,
Antitussive and expectorant such as methoxyphenamine hydrochloride, procaterol hydrochloride, tulopterol hydrochloride, clenpterol hydrochloride and ketotifen fumarate.

Anti-neoplastic agents such as cyclophosphamide, fluorouracil, degafur, mitomycin C, procarbazine hydrochloride, doxyfluridine, lanimustine; ethyl aminobenzoate, tetracaine hydrochloride, brocaine hydrochloride, dibucaine hydrochloride, oxybuprocaine hydrochloride,
Local anesthetic such as propitocaine hydrochloride.

Hormonal agents such as propylthiouracil, thiamazole, metelonone acetate, estradiol, estriol, progesterone; antihistamines such as diphenhydramine hydrochloride, chlorpheniramine maleate, promethazine, cyproheptadine hydrochloride, diphenylpyraline hydrochloride.

Anticoagulants such as warfarin potassium and ticlopidine hydrochloride; antispasmodic agents such as methylatropine bromide and scopolamine; general anesthetics such as thiopental sodium and pentobarbital sodium; hypnotic and analgesic such as bromvalenylurea, amobarbital and phenobarbital. Agents: antiepileptic agents such as phenytoin sodium.

Stimulants / stimulants such as methamphetamine hydrochloride; sedatives such as difendol hydrochloride and betahistine mesylate; psychotropic agents such as chlorpromazine hydrochloride, thioridazine, meprobamate, imipramine hydrochloride, chlordiazepoxide, diazepam; suskimethonium hydrochloride, eperisone hydrochloride, etc. Skeletal muscle relaxant; neostigmine bromide,
Agents for autonomic nerves such as bethanechol chloride; anti-Parkinson agents such as amantadine hydrochloride.

Diuretics such as hydroflumethiazide, isosorbide and furosemide; vasoconstrictors such as phenylephrine hydrochloride; respiratory stimulants such as lobeline hydrochloride, dimorphoramine and naloxone hydrochloride; glycopyrronium bromide, proglumide,
Remedies for peptic ulcer such as cetraxate hydrochloride, cimetidine, and spizofron; choleretic agents such as ursodesoxycholic acid and osalmid; agents for genitourinary and anus such as hexamine, spartine, dinoprost, and ritodrine hydrochloride.

Agents for parasitic skin diseases such as salicylic acid, ciclopirox olamine and croconazole hydrochloride; emollients such as urea; calcitriol, thiamine hydrochloride, sodium riboflavin phosphate, pyridoxine hydrochloride, nicotinic acid amide, panthenol, Vitamin preparations such as ascorbic acid; inorganic preparations such as calcium chloride, potassium iodide, sodium iodide.

Hemostatic agents such as ethanesylate; agents for liver diseases such as thiopronin; agents for addictive addiction such as cyanamide; agents for respiring colchicine, probenecid, sulfinpyrazone etc .; tolbutamide, chlorpropamide, sodium glymidine, glypzole. , Pformin hydrochloride, insulin and other antidiabetic agents.

Benzylpenicillin potassium, propicillin potassium, cloxacillin sodium, ampicillin sodium, bacampyricin hydrochloride, carbenicillin sodium, cephaloridine, cefoxitin sodium,
Antibiotics such as erythromycin, chloramphenicol, tetracycline, kanamycin sulfate and cycloserine; chemotherapeutic agents such as isocyanide, pyrazinamide and ethionamide; narcotics such as morphine hydrochloride, codeine phosphate, cocaine hydrochloride and pethidine hydrochloride.

The amount of the above-mentioned drug added varies depending on the type of the drug and the purpose of use of the tape preparation, but when the amount is small, a high drug release property cannot be obtained, and when the amount is large, the cohesive force and adhesive force of the pressure-sensitive adhesive layer decrease. , Usually in an adhesive composition of 0.01 to
50% by weight is preferred. However, there is no particular problem even if the drug exists in the pressure-sensitive adhesive layer in a supersaturated state or in a state in which crystals are precipitated. Further, the drug may be encapsulated with a transdermal absorption enhancer, or a drug storage layer may be provided.

The support preferably has flexibility, and when the pressure-sensitive adhesive layer contains a drug or other additives, it is preferably impermeable or hardly permeable. Examples of such a support include cellulose acetate, ethyl cellulose, polyethylene, polypropylene, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer, ethylene-methyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene- Resin films of vinyl acetate-carbon monoxide copolymer, polyvinylidene chloride, polyurethane, nylon, polyethylene terephthalate, polybutylene terephthalate and the like: aluminum sheets, which may be used as single layer sheets of these.
One or more kinds may be laminated and used. Further, the resin film and the aluminum sheet may be used as a laminate with a woven cloth or a nonwoven cloth.

If necessary, the surface of the support on which the pressure-sensitive adhesive layer is formed may be subjected to a surface treatment such as corona discharge treatment, chemical oxidation treatment or ozone treatment.

[0048]

EXAMPLES Next, examples of the present invention will be described. (Example 1)Synthesis of acrylic adhesive (1) 302 g (65 mol%) of 2-ethylhexyl acrylate
And N-vinyl-2-pyrrolidone 98 g (35 mol%)
Into a separable flask equipped with a stirrer and cooler.
In addition, 400 g of ethyl acetate was added to add the monomer concentration.
After adjusting the concentration to 50% by weight, this solution is placed under a nitrogen atmosphere.
The temperature was raised to 80 ° C and 2 g of lauroyl peroxide was added to cyclohexahexa.
A solution of 100 g of ethyl acetate and 243 g of ethyl acetate.
Polymerization reaction is carried out for 12 hours while adding gradually
35% by weight, viscosity 1.5 × 10 ^Fourcps acrylic
An ethyl acetate solution of adhesive (1) was obtained.

To the above acrylic adhesive solution, silicic acid anhydride was added so that the concentration in the solid content would be 5% by weight, and further 50 parts by weight of ethanol was added to 100 parts by weight of the total solid content to give a solid content of 30%. A weight% adhesive composition was obtained.

Example 2 Ethanol was added to a total solid content of 100.
A pressure-sensitive adhesive composition having a solid content concentration of 20% by weight was obtained in the same manner as in Example 1 except that 200 parts by weight was added to parts by weight.

Comparative Example 1 An adhesive composition having a solid content of 30% by weight was obtained except that ethyl acetate was added instead of ethanol.

(Comparative Example 2) Ethanol was added to a total solid content of 100
A pressure-sensitive adhesive composition having a solid content concentration of 3% by weight was obtained in the same manner as in Example 1 except that 3000 parts by weight was added to parts by weight.

Example 3 A solid content concentration of 20 was obtained in the same manner as in Example 1 except that 100 parts by weight of ethanol and acetone were added to 100 parts by weight of the total solid content.
A weight% adhesive composition was obtained.

(Example 4) 100 parts by weight of styrene-isoprene-styrene / block copolymer ("Califlex TR1107" manufactured by Shell Chemical Co., Ltd.), an alicyclic hydrogenated petroleum resin as a tackifier (manufactured by Arakawa Chemical Co., Ltd. Archon-P
90 ") 140 parts by weight and 25 parts by weight of polybutene (" HV-300 "manufactured by Nisseki Chemical Co., Ltd.) as a softening agent are dissolved in 490 parts by weight of an ethyl acetate / cyclohexane mixed solvent (weight ratio 1: 1) to obtain a solid content. A rubber-based pressure-sensitive adhesive solution having a concentration of 35% by weight was obtained. Silicic anhydride was added to the above rubber-based adhesive solution so that the concentration in the solid content was 3% by weight, and isopropyl alcohol was added to 50 parts by weight based on 100 parts by weight of the total solid content.
By adding parts by weight, an adhesive composition having a solid content concentration of 30% by weight was obtained.

Comparative Example 3 The same procedure as in Example 4 was repeated except that an ethyl acetate / cyclohexane mixed solvent (weight ratio 1: 1) was added instead of isopropyl alcohol.
An adhesive composition having a solid content concentration of 23% by weight was obtained.

(Example 5) Synthesis of acrylic pressure-sensitive adhesive (2) 200 g of ethyl acrylate, octyl acrylate 180
g and 20 g of N-vinyl-2-pyrrolidone were placed in a separable flask equipped with a stirrer and a cooling device, and 400 g of ethyl acetate was added to the mixture to give a monomer concentration of 50% by weight.
The temperature of this solution was raised to 80 ° C. under a nitrogen atmosphere, and a solution of 4 g of lauroyl peroxide dissolved in 100 g of cyclohexane and 243 g of ethyl acetate were added little by little to carry out a polymerization reaction for 12 hours to give a solid. A solution of acrylic adhesive (2) in ethyl acetate having a content of 35% by weight and a viscosity of 8 × 10 ⁴ cps was obtained.

Silica anhydride and isopropyl palmitate (plasticizer) were added to the above acrylic adhesive solution so that the concentrations in the solid content were 7 and 30% by weight, respectively, and isopropyl alcohol was added in an amount of 100 parts by weight in total solid content. 80 parts by weight was added to obtain a pressure-sensitive adhesive composition having a solid content concentration of 24% by weight.

(Comparative Example 4) The above acrylic adhesive (2)
Silica anhydride was added to the solution so that the concentration in the solid content was 7% by weight, and isopropyl palmitate (plasticizer) was added.
Was added to 100 parts by weight of the total solid content to obtain an adhesive composition having a solid content concentration of 24% by weight.

The pressure-sensitive adhesive compositions obtained in the above Examples and Comparative Examples were subjected to the following measurements and evaluations, and the results are shown in Table 1.
It was shown to. (1) Viscosity measurement The viscosity immediately after the preparation of the pressure-sensitive adhesive composition and two weeks after the preparation was measured at 25 ± 0.5 ° C using a B-type viscometer. (2) Evaluation of coatability Using the pressure-sensitive adhesive composition immediately after preparation and after 2 weeks from preparation, it was applied on a silicon-treated polyethylene terephthalate film having a thickness of 35 μm, dried, and the thickness after drying was 80 μm. After forming the pressure-sensitive adhesive layer of 1., it was visually observed whether or not a uniform pressure-sensitive adhesive layer was obtained. ◯: A uniform pressure-sensitive adhesive layer was formed. X: A uniform pressure-sensitive adhesive layer was not formed.

[0060]

[Table 1]

[0061]

The constitution of the pressure-sensitive adhesive composition of the present invention is as described above, and it is insoluble in water and is soluble in an organic solvent consisting of a lower alcohol alone or a mixed solvent thereof, silicic anhydride and By being made of the above organic solvent, the sticking property is excellent due to the balance performance of the adhesive force and the cohesive force,
Since the viscosity does not increase with time, mass production becomes easy. Further, when the pressure-sensitive adhesive composition is used as a pressure-sensitive adhesive layer of a patch, since the pressure-sensitive adhesive layer exhibits high cohesiveness while maintaining flexibility, sticking out of the pressure-sensitive adhesive or adhesive residue during peeling may occur. It won't happen.

Claims (1)

[Claims] 1. A pressure-sensitive adhesive composition which is insoluble in water and is soluble in an organic solvent consisting of a lower alcohol alone or a mixed solvent thereof and a solid content consisting of silicic acid anhydride, and the organic solvent. The adhesive composition contains 30 parts by weight or more of the organic solvent based on 100 parts by weight of the solid content, and the solid content is 5% by weight or more in the adhesive composition.