Razor Blade Coating with Depth-Variant Nanocrystals for Edge Durability

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Solution Overview

Problem

Conventional razor blade coatings face issues such as cracks between layers, increased process complexity, and inadequate control over adhesive force due to single-layer formations with uniform properties, which affect durability and edge shape control.

Innovation Solution

A razor blade with a coating layer comprising alternating first and second regions with different properties, where the first region has superior adhesive force and the second region has superior strength, formed through a single plasma chamber process, ensuring controlled edge shape and improved durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate layers are added to perform each role (hard coating, lubricating coating, interlayer coating), then the functional requirements are met, but the process complexity and number of steps increase

Engineering Contradiction:
Improvefunctional requirementsVSAvoidprocess complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple coating functions (hard coating, lubricating coating, and interlayer coating) into a single integrated coating layer formed by one deposition process. This merging eliminates the need for separate coating steps while maintaining all required functions, directly resolving the contradiction between functional completeness and process complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single coating layer is designed to perform multiple functions simultaneously: providing hardness through CrB nanocrystals, lubrication through the coating structure, and adhesion through the gradient composition. This multi-functionality allows one coating to replace several separate layers, reducing process steps while meeting all functional requirements

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If separate layers are added to perform each role, then functional requirements are met, but the number of steps in the process increases

Engineering Contradiction:
Improvefunctional requirementsVSAvoidnumber of steps
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent merges multiple coating applications into a single deposition process, forming all necessary coating regions (first coating region with high adhesive force, second coating region with high strength, and lubricating regions) in one step. This eliminates the time required for multiple separate coating steps while maintaining all functional requirements

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If uniform single-layer coating is used, then the process is simple, but cracks occur between coatings and adhesive force control becomes complex

Engineering Contradiction:
Improveprocess simplicityVSAvoidadhesive force stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies local quality by creating different regions within the single coating layer, each with specific local properties: the first coating region near the substrate has high adhesive force through its composition and structure, the second coating region has high strength through CrB nanocrystals, and lubricating regions provide low friction. This localized differentiation ensures stable adhesive force and prevents cracks while maintaining process simplicity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses parameter changes by varying the composition, structure, and morphology of the coating layer from one region to another within the same single layer. The gradient in CrB nanocrystal distribution, the variation in coating thickness, and the change in atomic composition create different local properties that ensure reliable adhesion and prevent cracking, all achieved through a single deposition process

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If conventional single-layer coating is used, then manufacturing is easier, but durability and edge shape control are insufficient

Engineering Contradiction:
Improvemanufacturing easeVSAvoiddurability
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent enhances durability by creating local quality differences within the single coating layer: the second coating region contains CrB nanocrystals that provide high strength and hardness, while the first coating region provides strong adhesion to the substrate. This localized optimization of material properties within one coating layer achieves superior durability without complicating the manufacturing process

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4667619A1Razor blade
Publication Date: 2025.12.24 DORCO CO LTD
  • EP4667619A1 patent drawingFigure 1
  • EP4667619A1 patent drawingFigure 2
  • EP4667619A1 patent drawingFigure 3

AI summary

The present disclosure relates to a razor blade including: a blade substrate having a blade edge formed therein; and a coating layer formed on the blade substrate, wherein the coating layer contains a matrix-forming atom, a first atom, and a second atom, the coating layer contains a first coating region and a second coating region located at different depths in the thickness direction, and the second coating region has a larger number of nanocrystal regions than the first coating region.