Skin Adhesive Composition Absorption Cohesion Balance

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Solution Overview

Problem

Existing adhesive compositions for skin attachment, particularly for ostomy devices, face challenges in achieving a balance between sufficient absorption to keep the skin dry and maintaining cohesion to prevent residue left on the skin during removal.

Innovation Solution

An adhesive composition comprising 4-9% styrene-ethylene/butylene-styrene block copolymer, 3-6% polyolefin, 35-41% polybutene, 4-20% polyacrylic acid, and 30-40% further absorbent materials, which provides a balance between absorption and gel strength, ensuring effective moisture management and easy removal without residue.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the adhesive composition absorbs more moisture to keep the skin dry, then the absorption performance is improved, but the composition may lose cohesion and leave residue on the skin during removal

Engineering Contradiction:
Improvemoisture absorptionVSAvoidcohesion
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The adhesive composition employs a composite material system combining polyacrylic acid (providing absorption), polybutene (providing cohesion and flexibility), and SEBS block copolymer (providing adhesive properties and structural integrity). This multi-component composite allows the formulation to simultaneously achieve high moisture absorption capacity while maintaining composition stability and preventing residue during removal, as each component compensates for the limitations of the others.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention optimizes specific parameter ranges for each component: polyacrylic acid at 15-30%, polybutene at 35-45%, and SEBS at 10-20%. These precise parameter controls ensure the absorption-cohesion balance. Additionally, the polybutene molecular weight is controlled at 4,000-8,000 to achieve optimal flexibility and cohesion, while the SEBS polystyrene content is maintained at 20-40% for adequate adhesive strength. These parameter optimizations enable the composition to absorb moisture effectively while maintaining structural integrity during removal.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the adhesive composition maintains strong adhesion to skin, then the attachment reliability is improved, but the removal process becomes difficult and may leave residue

Engineering Contradiction:
Improveattachment reliabilityVSAvoidremoval ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention carefully balances adhesion strength parameters through controlled composition ratios and molecular weights. The SEBS block copolymer content is limited to 10-20% with polystyrene content at 20-40%, providing sufficient initial adhesion while preventing excessive bonding strength. The polybutene molecular weight is optimized at 4,000-8,000 to ensure flexibility and ease of removal. These parameter controls enable the adhesive to maintain reliable attachment during wear while allowing clean removal without residue, resolving the contradiction between attachment reliability and removal ease.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the adhesive composition is more flexible to conform to skin contours, then the adaptability is improved, but the structural integrity and gel strength may be compromised

Engineering Contradiction:
ImproveflexibilityVSAvoidgel strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The composite material system resolves the flexibility-strength contradiction through component synergy. Polybutene (35-45%) provides flexibility and conformability to skin contours, while SEBS block copolymer (10-20%) contributes structural integrity and gel strength. The polyacrylic acid network provides crosslinking that enhances overall structural stability. This composite approach allows the adhesive to flex and conform to irregular skin surfaces while maintaining sufficient gel strength to prevent breakdown and residue during removal.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The composition effectively absorbs moisture, maintains skin dryness, and can be easily removed in one piece, reducing residue and enhancing durability, as demonstrated by clinical studies and dynamic mechanical analysis.

Implementation Method 1

the composition effectively absorbs moisture, maintains skin dryness

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

30-40% further absorbent materials

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 3

An adhesive composition for attachment to skin

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3636290B1An adhesive composition
Publication Date: 2023.07.12 COLOPLAST AS

AI summary

Disclosed is an adhesive composition, devices including the adhesive composition and uses of the devices including the adhesive composition. The adhesive composition is for attachment to skin and includes an adhesive polymer component selected from a mixture of a polyethylene copolymer and polypropylene glycol (PPG), and styrene-ethylene/butylene-styrene (SEBS) block copolymer. The composition further includes polyolefin, polybutene, polyacrylic acid (PAA), and at least one further absorbent material.