EP0758908A1

EP0758908A1 - Medical self-adhesive mass with high water vapour permeability and high adhesiveness on dry or perspiration-wet human skin

Info

Publication number: EP0758908A1
Application number: EP95919416A
Authority: EP
Inventors: Zbigniew Czech; Kurt Seeger
Original assignee: Lohmann GmbH and Co KG
Current assignee: Lohmann GmbH and Co KG
Priority date: 1994-05-13
Filing date: 1995-05-05
Publication date: 1997-02-26
Also published as: DE4416928C1; US5785985A; HUT75675A; JPH10500328A; WO1995031224A1; PL317160A1; NO964798L; NO964798D0; HU9603118D0; HU216297B

Abstract

A medical self-adhesive mass has a water vapour permeability of at least 10,000 g/m2/24h (measured on a self-adhesive film weighing 30 g/m2) and an excellent adhesiveness both on dry and perspiration-wet skin. The mass is characterised in that it contains a copolymer synthesised from components (a) 50 to 95 % by weight, preferably 70 to 90 % by weight, of one or several alkyl esters of acrylic and/or methacrylic acid with 4 to 12 C atoms in the alkyl residue; (b) 5 to 50 % by weight, preferably 10 to 30 % by weight, of a vinyl carboxylic acid, with respect to the copolymer, and in that it is mixed with additional components (c) 25 to 90 % by weight, preferably 50 to 80 % by weight of a tertiary or quaternary ammonium group-containing hydrophilic emulsifier; (d) 15 to 60 % by weight, preferably 20 to 40 % by weight, of a hydrophilic, polyoxyalkylene group-containing, amine group-free emulsifier; (e) 1 to 20 % by weight preferably 3 to 15 % by weight of a polyvinyl acid; (F) 1 to 15 % by weight, preferably 3 to 10 % by weight, of a tackifying resin; and (g) 0.05 to 5 % by weight, preferably 0.1 to 2 % by weight, of a cross-linking agent.

Description

Medical pressure sensitive adhesive with high water vapor permeability and high adhesive strength on dry human skin as well as with strong perspiration

The present invention relates to medical pressure-sensitive adhesives with high water vapor transmission rate (WVTR) of at least 10,000 g / m ^2/24 × h (measured by the inverted cup method at 40 ° C and 80% Δ rH on a pressure-sensitive adhesive film having a weight of 30 g / m ³ ) and excellent adhesion to dry and highly perspiring skin as well as their manufacture and use.

Medical PSAs with high WDD or high adhesive strength to skin that is moist due to strong perspiration are known. However, these PSAs have disadvantages that severely restrict their practical use.

The state of the art in this field can be described as follows:

DS-A 5057179 describes a polar dispersion based on polyvinyl acetate with good adhesion to moist substrates.

JP-A 3162473 describes a pressure sensitive adhesive with adhesion to moist surfaces. This PSA consists of an acrylate copolymer based on alkyl acrylate, alkylene alkoxy acrylate and vinyl carboxylic acid and an ethylene vinyl acetate copolymer.

JP-A 30068672 includes adhesive tapes for medical plasters that adhere to damp or dry skin. Products of this type contain silicone PSAs and water-soluble carboxyvinyl polymers, cellulose or starch derivatives.

JP-A 62091577 describes PSAs with pronounced adhesion to dry and moist substrates, the Adhesion to damp surfaces was achieved by installing water absorbers based on cross-linked polyacrylate salts.

JP-A 61290956 describes resins for medical PSAs, composed of acrylamide derivatives, (meth) acrylates and glycol acrylic acid esters.

WO 84013837 describes PSAs which are particularly suitable for moist skin, based on copolymers of hydrophobic acrylates, hydrophobic vinyl polyethers and polar monomers. (Meth) acrylic acid, itaconic acid, (meth) acrylamide or n-vinylpyrrolidone is used as a polar monomer.

GB-A 2070631 describes copolymers of butyl acrylate, ethylhexyl acrylate and acrylic acid for use in medical products. These copolymers have, in addition cohesive properties of adhesion to dry and moist skin and a vapor permeability of above 300 g / m ^2/24 × h from.

The prior art comprises differently composed PSAs which adhere to dry and damp skin, but whose adhesive strength is reduced in the case of strong perspiration so that their use for plasters is not possible.

For many PSAs classified as medically suitable, attention was only paid to the physiological safety of the raw materials used, but not to the WDD for adhesive midical products, also called breathability. However, this is just as important for protecting the skin from maceration, which is caused by moisture build-up under the adhesive, as well as for permanent adhesion to the skin, which is also greatly affected by moisture build-up. There are only few statements about the WDD values of the PSAs according to the state of the art. Due to their chemical composition it can be concluded that they are at a level which is not sufficient for use in the case of strong perspiration. For example, the value specified in GB-A 2070631 as the "lower limit" of the WDD is 300

g / m ^2/24 × h woefully inadequate even at low transpiration.

The achievable with known PSAs WDD values are after winning by checking experience in adhesive layers with about 30 g / m ² basis weight at 1,000 to 8,000 g / m ^2/24 × h, which is sufficient in some cases, but is considered to be improved. The known medical PSAs are often difficult to modify due to their chemical structure with regard to increasing the WDD. The addition of hydrophilic components often leads to a drastic decrease in the adhesive force when used on human skin, since the partial swelling of the hydrophilic components adversely affects the adhesive

Ingredients stand out from the skin.

Starting from this prior art, the present invention has the object to provide medical pressure sensitive adhesives which do not show the mentioned drawbacks, and a WVTR of at least 10,000 g / m ^2/24 × h (at 30 g / m ² film weight) with excellent Adhere to both dry and strong perspiration on damp skin.

The solution to the problem was surprisingly found with the following composition of the medical PSA, which is a copolymer synthesized from the components a) 50 to 95% by weight, preferably 70 to 90% by weight, of one or more alkyl esters of acrylic and / or methacrylic acid with 4 to 12 carbon atoms in the alkyl radical, and b) 5 to 50% by weight , preferably 10 to .30 wt .-% of a vinyl carboxylic acid, based on the copolymer and with other components, c) 25 to 90 wt .-%, preferably 50 to 80 wt .-% of a tertiary or quaternary ammonium-containing, hydrophilic emulsifier , d) 15 to 60% by weight, preferably 20 to 40% by weight of a hydrophilic, polyoxyalkylene group-containing, amine group-free emulsifier, e) 1 to 20% by weight, preferably 3 to 15% by weight of a polyvinyl carboxylic acid, f) 1 to 15% by weight, preferably 3 to 10% by weight of a tackifying resin and g) 0.05 to 5% by weight, preferably 0.1 to 2% by weight of one

Crosslinking agent. is mixed.

The medical PSA of the invention consists of copolymers, synthesized from tackifying alkyl esters of (meth) acrylic acid with 4 to 12 carbon atoms in the alkyl radical and vinyl carboxylic acid (s), which are modified after synthesis with the remaining components c to g to give the finished PSAs. The PSA of the invention is explained in more detail below.

The pressure-sensitive adhesive properties of the polyacrylate PSAs can be influenced by the selection of the tackifying monomers. The alkyl esters of acrylic and / or methacrylic acid with 4 to 12 carbon atoms in the alkyl radical come from the group consisting of n-butyl, isobutyl, tertiary-butyl, pentyl, hexyl, heptyl, octyl and isooctyl -, 2-ethylhexyl, 2-methylheptyl, nonyl, decyl and isodecyl acrylate and / or methacrylate, n-butyl acrylate and 2-ethylhexyl acrylate being preferred.

To introduce carboxyl groups into the polymer chains, vinyl carboxylic acids are used as comonomers, which are selected from (meth) acrylic acid, β-acryloyloxypropionic acid, dimethylacrylic acid, trichloracrylic acid, vinyl acetic acid, fumaric acid, crotonic acid, aconitic acid or itaconic acid. Acrylic acid and β-acryloyloxypriopionic acid are preferred as particularly suitable vinyl carboxylic acids.

Additional hydrophilic groups are added by admixing a hydrophilic emulsifier containing tertiary or quaternary ammonium groups with an HLB value (hydrophilic-lipophilic balance) of 10 to 20. Ethoxylated amines such as N, N ', N'-tris (2-hydroxyethyl) -N-tallow-1,3-diaminopropane and tallow propylene diamine polyglycol ether have proven to be particularly suitable.

Furthermore, the addition of a hydrophilic, polyoxyalkylene group-containing, amine group-free emulsifier has been found to be advantageous without the adhesive force on dry skin and through perspiration damp skin being adversely affected. Preferred hydrophilic amine group-free emulsifiers are polyoxyalkylenes such as polyethylene glycols or Polypro pylene glycols with a molecular mass between 200 and 10,000 are used. Polyethylene glycol 400 and polyethylene glycol 600 have proven to be particularly suitable.

In order to be able to remove coated medical PSAs in the form of plasters easily and gently from the skin, tackifying resins are used, with hydrogenated or partially hydrogenated hydrocarbon resins and hydrogenated or partially hydrogenated derivatives of abietic acid in amounts of up to 15% by weight having proven to be suitable .

In order to give the polyacrylate PSAs an acceptable internal strength, crosslinking agents which react with carboxyl groups are used, such as, for example, metal chelates, metal acid esters, epoxy, aziridine or triazine resins. Metal chelates such as aluminum, hafnium, titanium, zirconium or iron acetylacetonate have proven particularly suitable. Of the metal acid esters, polytitanic acid esters are preferred, e.g. Polybutyl titanate.

If the copolymer can be prepared by customary solvent polymerization, esters of saturated carboxylic acids (such as ethyl acetate), aliphatic hydrocarbons (such as n-heptane), aliphatic ketones (such as acetone or ethyl methyl ketone), mineral spirits or the mixtures of these solvents can be used as solvents. Azo compounds such as 2,2'-azobis- (2,4-dimethylpentanitrile), 2,2'-azobis- (2-methyl-propanonitrile), 2,2'-azobis- (2-methyl-butanonitrile) are usually used as radical initiators. or

1,1'-azobis (cyclohexane carbonitrile) or peroxides such as e.g. Di-benzoyl peroxide used.

A method for producing the medical PSA provides that the copolymer of components a) and b) is synthesized and mixed with the other components c) to g), the sum of the proportions by weight of all components being 100% by weight.

The invention also relates to the use of the medical PSAs of the invention for the production of sweat-resistant occlusive dressings, highly water-vapor-permeable wound dressings and medical adhesive tapes for use in the sports field. If required, these medical products can be sterilized by steam, γ-radiation or gassing with ethylene oxide.

The medical pressure-sensitive adhesive composition of the invention is characterized by an extremely high water vapor permeability at a level above 28,000 g / m ^2/24 × h from. Your adhesion to dry and highly perspiring skin is good. The removal from the skin can be carried out gently and softly, no skin irritation or allergy symptoms are observed. These PSAs are ideal for the adhesive finishing of various medical products such as perspiration-resistant occlusive dressings, highly water vapor-permeable wound dressings and adhesive tapes for the sports sector.

The medical products produced with the PSA according to the invention were assessed by physical and technical tests such as WDD and testing the adhesive strength on steel plates in accordance with AFERA 4001. The adhesive strength was tested on the intact skin of 5 test subjects by applying 2.5 cm wide strips on the hairless surface Inside of the forearms and measurement of the adhesive force after 10 min and after 3 hours in accordance with AFERA 4001. Further assessment criteria here were skin compatibility and residue-free peeling. The statistical evaluation showed that products with the PSAs of the invention had no problem on human skin no significant skin irritation and can be removed without leaving any residue.

The invention is illustrated by the following example:

Example 1;

200 g copolymer solution, polymerized from 80 g n-butyl acrylate and 20 g acrylic acid in 100 g ethyl acetate, with an average molecular mass of 600,000 daltons, are mixed at room temperature with 70 g tallow propylene diaminopolyglycol ether, 30 g polyethylene glycol 400, 15 g polyacrylic acid with an average molecular mass of 400,000 Dalton, 6 g of the glycerol ester of dihydroabietic acid and 1 g of aluminum acetylacetonate mixed.

The PSA obtained in this way is coated with a coating knife in different layer thicknesses onto a siliconized polyester film and at 100 ° C. for 30 min in a drying cabinet to form PSA films with a thickness of a) 20 μm

b) 30 μm

c) 40 μm

dried. The pressure-sensitive adhesive films are applied to a 25 micron thick polyurethane film having a WVTR of 40,000 g / m ^2/24 × h

owns, transfer-laminated. The test (see Table 1) was carried out in comparison to a commercial competitive product d) which has a 30 μm thick PSA film. In addition to the physical-technical tests, there is also a 24-hour wear test with 5 × 7 cm Sections. While skin maceration, caused by moisture build-up under the adhesive film, is observed in the competition product, the test subjects' skin is completely dry under the test sections coated with the PSA of the invention.

A comparison of the competition shows an approximately the same level of adhesive strength when measured after 10 minutes. The performance of the new pressure-sensitive adhesive is shown in the measurement after 3 hours. While the adhesive strength of the competition product in most test subjects decreases and sometimes even no longer suffices for sufficient adhesion, the adhesive strength of the PSA according to the invention increases in most cases. The explanation can be found by looking at the WDD values, which for the competitor product are significantly lower than those of the PSA of the invention. Examples 2 to 15 were implemented analogously to Example 1.

The exact composition of the starting materials for the production of the medical PSAs according to the invention can be seen in Table 2, the results of the test with 30 μm thick PSA films are summarized in Table 3.

The abbreviations used in the tables are listed below.

List of abbreviations:

Table 2:

2-EHA - 2-ethylhexyl acrylate

AlACA - aluminum acetylacetonate

AS - acrylic acid

APS - ß-Acryloyloxypropionic acid

BA - butyl acrylate

KWH - hydrocarbon resin

GEDA - glycerol ester of dihydroabietic acid

HfACA - hafnium acetylacetonate

PAS - polyacrylic acid

PBT - polybutyl titanate

PEG 400 - polyethylene glycol with a molecular mass of 400

PEG 600 - polyethylene glycol with a molecular mass of 600

PEG-DME 500 - polyethylene glycol dimethyl ether with one

Molecular mass of 500

THTD - N, N ', N'-tris (2-hydroxethyl) -N-tallow-1,3-diaminopropane

TPD - tallow propylene diaminopolyglycol ether

The above test results consistently show that the medical pressure-sensitive adhesive according to the invention is characterized by an extremely high water vapor permeability at a level above 28,000 g / m ^2/24 × h. Your adhesion to dry and highly perspiring skin is good. The removal from the skin can be carried out gently and softly, no skin irritation or allergy symptoms are observed. These PSAs are ideal for the adhesive finishing of various medical products such as

sweat-resistant occlusive bandages, highly water vapor permeable wound dressings and adhesive tapes for the sports sector.

Claims

PATEN TAN SPEECH

1. Medical pressure-sensitive adhesive having a water vapor permeability of at least 10,000 g / m ^2/24 × h (measured at a Haftklebstoffilm with a weight of 30 g / m ²⁾ and an excellent adhesion in both dry as well as wet through transpiration skin, characterized that they synthesized a copolymer from components a) 50 to 95% by weight, preferably 70 to 90% by weight, of one or more alkyl esters of acrylic and / or methacrylic acid with 4 to 12 carbon atoms in the alkyl radical, b) 5 to 50 wt .-%, preferably 10 to 30 wt .-% of a vinyl carboxylic acid, based on the copolymer, contains and with other components

c) 25 to 90% by weight, preferably 50 to 80% by weight, of a hydrophilic emulsifier containing tertiary or quaternary ammonium groups,

d) 15 to 60% by weight, preferably 20 to 40% by weight, of a hydrophilic, polyoxyalkylene group-containing, amine group-free emulsifier,

e) 1 to 20 wt .-%, preferably 3 to 15 wt .-% of one

Polyvinyl carboxylic acid,

f) 1 to 15 wt .-%, preferably 3 to 10 wt .-% of a tackifying resin and

g) 0.05 to 5% by weight, preferably 0.1 to 2% by weight, of a crosslinking agent is mixed.

2. Medical PSA according to claim 1, characterized in that the (meth) acrylic acid alkyl ester having 4 to 12 carbon atoms in the alkyl radical from the group consisting of n-butyl, isobutyl, tertiary butyl, pentyl, Hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, 2-methylheptyl, nonyl, decyl and isodecyl acrylate and / or methacrylate is selected.

3. Medical PSA according to claim 1, characterized in that the tertiary or quaternary ammonium group-containing, hydrophilic emulsifier has an HLB value of 10 to 20 and is selected from the group of ethoxylated amines.

4. Medical PSA according to claim 1, characterized in that the hydrophilic, polyoxalkylene group-containing, amine group-free emulsifier is selected from the group of aliphatic polyoxyalkylenes with a molecular weight between 200 and 10,000.

5. Medical PSA according to claim 1, characterized in that the vinyl carboxylic acid is selected from the group consisting of (meth) acrylic acid, ß-acryloyloxypropionic acid, dimethylacrylic acid, trichloracrylic acid, vinyl acetic acid, fumaric acid, crotonic acid, aconitic acid or itaconic acid or mixtures of these acids.

6. Medical PSA according to claim 1, characterized in that the polyvinyl carboxylic acid is an uncrosslinked polyvinyl carboxylic acid.

7. Medical PSA according to claim 6, characterized in that the polyvinyl carboxylic acid is polyacrylic acid.

8. Medical PSA according to claim 1, characterized in that the tackifying resin from the group of hydrogenated or partially hydrogenated hydrocarbon Resins and / or group of hydrogenated or partially hydrogenated abietic acid derivatives is selected.

9. Medical PSA according to claim 1, characterized in that the crosslinking agent is a metal chelate, a metal acid ester, an epoxy, an aziridine or a triazine resin.

10. Medical PSA according to claims 1 to 9, characterized in that it can be sterilized.

11. A process for producing a medical PSA according to claims 1 to 10, characterized in that the copolymer is synthesized from components a) and b) and mixed with the other components c) to g).

12. Use of the medical PSA according to claims 1 to 11 for the production of sweat-resistant occlusive dressings.

13. Use of the medical PSA according to claims 1 to 11 for the production of highly water vapor permeable wound dressings.

14. Use of the medical PSA according to claims 1 to 11 for the manufacture of medical adhesive tapes for athletes.