Double-Structured Stick Cosmetic with Alkyl-Modified Silicone Outer Layer

Solution Overview

Problem

Existing stick cosmetics face challenges in achieving both mechanical strength and usability, such as smoothness and long-lasting effects, especially with fine core diameters, as increasing wax for mechanical strength degrades smoothness and vice versa, and manufacturing methods struggle with shape retainability of double-structured cosmetics.

Innovation Solution

A double-structured stick cosmetic with a solid-form outer layer containing alkyl-modified silicone and wax, where the alkyl-modified silicone has a specific melting point and mass ratio, combined with a semi-solid or paste-form inner core, to enhance shape retainability, smoothness, and impact resistance, along with a manufacturing method involving specific mold configurations and composition blending.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the amount of wax is increased to increase mechanical strength, then impact resistance is improved, but smoothness when drawing is degraded

Engineering Contradiction:

Improvemechanical strengthVSAvoidsmoothness when drawing

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The stick cosmetic is divided into two distinct structural components: an inner core containing wax and a outer layer containing alkyl-modified silicone. This segmentation allows each component to perform its specific function - the inner core provides mechanical strength while the outer layer provides smoothness - without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the stick cosmetic have different compositions and properties. The inner core has high wax content for strength, while the outer layer has high alkyl-modified silicone content for smoothness. This local differentiation of material properties resolves the contradiction between strength and smoothness.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If the area of the inner core is increased to improve feeling of use, then smoothness is improved, but mechanical strength is degraded

Engineering Contradiction:

Improvefeeling of useVSAvoidmechanical strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The stick cosmetic is divided into two distinct structural components: an inner core containing wax and a outer layer containing alkyl-modified silicone. This segmentation allows each component to perform its specific function - the inner core provides mechanical strength while the outer layer provides smoothness - without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The stick cosmetic uses a composite structure combining wax and alkyl-modified silicone in specific proportions. The outer layer contains 5-50 mass% alkyl-modified silicone combined with wax, creating a composite material that simultaneously provides both strength and smoothness properties that neither material could achieve alone.

Inventive Principle:

Principle #40Composite materials

3Strength

If the thickness of the outer layer is increased to improve mechanical strength, then impact resistance is improved, but feeling of use is degraded

Engineering Contradiction:

Improveimpact resistanceVSAvoidfeeling of use

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The invention changes the material parameters of the outer layer by incorporating alkyl-modified silicone with specific properties (melting point 25-60°C, specific viscosity) in controlled amounts (5-50 mass%). This parameter optimization allows the outer layer to provide both protection and comfort without requiring excessive thickness.

Inventive Principle:

Principle #35Parameter changes

4Ease of manufacture

If the writing-core is made elongated to improve manufacturing, then ease of manufacture is improved, but shape retainability is degraded

Engineering Contradiction:

Improveease of manufactureVSAvoidshape retainability

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The stick cosmetic uses a composite structure combining wax and alkyl-modified silicone in specific proportions. The outer layer contains 5-50 mass% alkyl-modified silicone combined with wax, creating a composite material that simultaneously provides both strength and smoothness properties that neither material could achieve alone.

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 solution provides excellent shape retainability during manufacturing, smoothness during application, and impact resistance, making it suitable for fine core diameters, while maintaining compatibility with mechanical strength and usability.

Implementation Method 1

the first oil composition contains (A) an alkyl-modified silicone having an alkyl group having 16 to 50 carbon atoms and (B) a wax in a solid-form at 25° C. other than (A)

Methodology Applied

Scientific EffectMelting point control: Melting

Data Source

PatentUS11964034B2Double-structured stick cosmetic and manufacturing method thereof

Publication Date: 2024.04.23 TOKIWA CORP

AI summary

A double-structured stick cosmetic includes a solid-form outer layer containing a first oil composition, and an inner core containing a second oil composition, in which the first oil composition contains (A) an alkyl-modified silicone having an alkyl group having 16 to 50 carbon atoms and (B) a wax in a solid-form at 25° C. other than (A). The component (A) may have a melting point of 25° C. or higher and 50° C. or lower. A mass ratio [(A)/(B)] of the component (A) to the component (B) contained in the first oil composition may be 0.2 or larger and 1.5 or smaller.