Adhesive Patch Spunlace Support Firmness

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Solution Overview

Problem

Adhesive patches with woven fabric supports have poor firmness, leading to application difficulties and adhesive agent exudation due to cold flow in nonwoven fabric supports.

Innovation Solution

Combining a spunlace nonwoven fabric support with an adhesive agent layer containing styrene-isoprene-styrene block copolymer and liquid paraffin, with a bending resistance of 18 to 30 mm, and a mass ratio of 1:1.65, to enhance firmness and prevent adhesive agent exudation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If woven fabric is used for the support, then stretchability and adherability are improved, but firmness deteriorates

Engineering Contradiction:
ImprovestretchabilityVSAvoidfirmness
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent uses a composite structure combining spunlace nonwoven fabric (providing firmness) with an adhesive agent layer containing styrene-isoprene-styrene block copolymer and liquid paraffin (providing stretchability and adherability). This composite approach allows the support to maintain firmness while the adhesive layer provides the necessary stretchability to conform to skin stretching.

Inventive Principle:
Principle #40Composite materials

2Strength

If nonwoven fabric is used for the support, then firmness is improved, but adhesive agent exudation occurs due to cold flow

Engineering Contradiction:
ImprovefirmnessVSAvoidadhesive agent exudation
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the adhesive agent layer by incorporating liquid paraffin (17.9 to 27.5% by mass) alongside the styrene-isoprene-styrene block copolymer. This compositional parameter change modifies the rheological properties of the adhesive layer, reducing its susceptibility to cold flow and preventing adhesive agent exudation from the support while maintaining firmness.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the adhesive patch has high firmness, then application difficulty is reduced, but adhesive agent exudation increases

Engineering Contradiction:
Improveease of applicationVSAvoidadhesive agent exudation
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent introduces liquid paraffin as an intermediary substance in the adhesive agent layer that mediates between the firmness requirement and the prevention of adhesive agent exudation. The liquid paraffin acts as a flow modifier that reduces cold flow susceptibility, allowing the adhesive patch to maintain high firmness for easy application while preventing harmful adhesive agent exudation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3254677B1Adhesive patch
Publication Date: 2021.08.04 HISAMITSU PHARM CO INC

AI summary

Disclosed is an adhesive patch having a support and an adhesive agent layer laminated on the support, wherein the support consists of spunlace nonwoven fabric, the adhesive agent layer comprises an SIS block copolymer and liquid paraffin, the adhesive patch has a first direction, which is a predetermined reference axis direction, and a second direction, which is orthogonal to the first direction, and a bending resistance in the first direction of the adhesive patch is 18 to 30 mm.