Cleansing Sheet Preservative System for Sensitive Skin

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Solution Overview

Problem

Conventional cleansing sheets with high water content allow bacterial growth and can irritate delicate skin, especially when used on infants or elderly people, due to the need for reduced bactericidal preservatives and the potential skin issues caused by moisturizers.

Innovation Solution

A cleansing sheet composed of a nonwoven sheet impregnated with a cleaning agent containing 99.80 wt % to less than 99.95 wt % purified water and 0.05 wt % to 0.20 wt % bactericidal preservative, with benzalkonium chloride, iodopropynyl butylcarbamate, and propylene glycol or 1,3-butylene glycol, which effectively prevents bacterial and fungal growth while minimizing skin irritation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If water content in cleaning agent is increased to reduce preservative content, then skin irritation is reduced, but bacterial growth is promoted

Engineering Contradiction:
Improveskin irritationVSAvoidbacterial growth prevention
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the cleaning agent by replacing traditional preservatives (phenoxyethanol, methylisothiazolinone) with alternative substances (ethylhexylglycerin, caprylyl glycol) and adjusting their concentrations. This allows maintaining high water content (96-99.5 wt%) for reduced skin irritation while achieving effective bacterial growth prevention through the new preservative system.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces ethylhexylglycerin and caprylyl glycol as intermediary substances that mediate between the conflicting requirements of high water content and bacterial prevention. These substances act as alternative preservatives that are effective at lower concentrations and are gentler on skin, bridging the gap between the two opposing needs.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If moisturizers are added to improve skin feel, then wiping comfort is enhanced, but skin problems may occur in infants and elderly people

Engineering Contradiction:
Improvewiping comfortVSAvoidskin problems
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent adjusts the concentration parameters of moisturizing agents (alcohol 5-20 wt%, aqueous moisturizer 1-10 wt%) to optimize the balance between wiping comfort and skin safety. By controlling these parameters within specific ranges, the patent achieves sufficient moisturizing effect for comfort while minimizing potential skin problems for sensitive groups.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different moisturizing components strategically - using alcohol for immediate wiping comfort and aqueous moisturizers for sustained hydration. This localized application of different moisturizing mechanisms ensures comfort for average users while the controlled concentrations prevent excessive irritation for infants and elderly people.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If bactericidal preservative content is reduced to minimize skin irritation, then skin safety is improved, but bacterial growth prevention becomes insufficient

Engineering Contradiction:
Improveskin irritationVSAvoidbacterial growth prevention
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent creates a composite preservative system combining ethylhexylglycerin (0.5-5 wt%) and caprylyl glycol (0.5-5 wt%) with traditional preservatives at reduced concentrations. This composite approach leverages the synergistic effects of multiple substances to achieve effective bacterial growth prevention while maintaining lower overall preservative content for reduced skin irritation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent introduces ethylhexylglycerin and caprylyl glycol as intermediary preservative substances that are less irritating to skin but effective at preventing bacterial growth. These intermediaries replace or supplement traditional harsh preservatives, allowing the formulation to maintain reliability in bacterial prevention with improved skin safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 cleansing sheet provides reliable antibacterial and antifungal protection with a minimized bactericidal preservative content, suitable for delicate skin, and can be stored for a long period without contamination, reducing the risk of skin problems and bacterial growth.

Implementation Method 1

the bactericidal preservative comprising more than 0.025 wt % to 0.10 wt % benzalkonium chloride, more than 0.0025 wt % to 0.01 wt % iodopropynyl butylcarbamate

Methodology Applied
Scientific EffectAntimicrobial action: Preservative

Implementation Method 2

a nonwoven sheet impregnated with a cleaning agent

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 3

a nonwoven sheet impregnated with a cleaning agent

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentUS8785367B2Cleansing sheet
Publication Date: 2014.07.22 LEC INC

AI summary

A cleansing sheet including a nonwoven sheet impregnated with a cleaning agent, the cleaning agent containing 99.80 wt % to less than 99.95 wt % of purified water and more than 0.05 wt % to 0.20 wt % of a bactericidal preservative, the bactericidal preservative including more than 0.025 wt % to 0.10 wt % benzalkonium chloride, more than 0.0025 wt % to 0.01 wt % iodopropynyl butylcarbamate, and more than 0.0225 wt % to 0.09 wt % glycol, based on the total weight of the cleaning agent taken as 100 wt %. The cleaning sheet can be applied to the delicate skin of infants or the sensitive skin of elderly people.