Rubber Composition for 3D Additive Manufacturing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current additive manufacturing methods primarily focus on producing three-dimensional structures using resins, which lack the temperature independence and low compression set characteristics of rubber, limiting their applications.

Innovation Solution

A rubber composition for additive manufacturing comprising liquid rubber and polyrotaxane, with a radical initiator, is used to produce three-dimensional rubber structures with specific mechanical properties, such as Shore A hardness, tensile strength, and compression set, through layer deposition and curing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resin-based additive manufacturing is used, then three-dimensional structures can be produced, but the structures lack temperature independence and low compression set characteristics

Engineering Contradiction:
Improvetemperature independence and low compression setVSAvoidapplication range
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention changes the material parameter from resin to rubber composition, specifically using liquid rubber with crosslinkable groups that can be cured to form elastic networks. This parameter change grants the material temperature independence and low compression set characteristics, resolving the contradiction between reliability and application versatility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite system comprising liquid rubber, crosslinking agent, and catalyst, which when cured together form a rubber-shaped article with superior mechanical properties. This composite approach enables both the reliability (temperature independence, low compression set) and adaptability (diverse applications) that neither resin alone nor simple rubber formulations could achieve.

Inventive Principle:
Principle #40Composite materials

2Reliability

If rubber composition is used for additive manufacturing, then temperature independence and low compression set are achieved, but the composition must be carefully formulated with specific components

Engineering Contradiction:
Improvetemperature independence and low compression setVSAvoidcomposition formulation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention performs preliminary action by pre-formulating the rubber composition with all necessary components (liquid rubber, crosslinking agent, catalyst) in appropriate proportions before the additive manufacturing process. This preliminary preparation simplifies the manufacturing process while ensuring the cured product achieves the desired reliability characteristics of temperature independence and low compression set.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention specifies precise parameter ranges for the composition components (e.g., liquid rubber content of 70-90 mass%, number average molecular weight of 5,000-60,000) to optimize both the formulation complexity and the final product reliability. By controlling these parameters, the invention balances composition complexity with achieving superior mechanical properties.

Inventive Principle:
Principle #35Parameter changes

3Strength

If liquid rubber with crosslinkable groups is used, then good adhesion and mechanical properties are achieved, but the molecular weight must be controlled within specific range

Engineering Contradiction:
Improveadhesion and mechanical propertiesVSAvoidmolecular weight control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The invention controls the molecular weight parameter of the liquid rubber within a specific range (number average molecular weight of 5,000-60,000) to achieve optimal balance between adhesion, mechanical properties, and processability. This precise parameter control ensures that the rubber composition forms strong bonds during additive manufacturing while maintaining the desired mechanical strength and elasticity in the final product.

Inventive Principle:
Principle #35Parameter changes

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 enables the production of rubber shaped articles with improved mechanical properties, allowing for diverse applications beyond those of resin-based structures, leveraging the temperature independence and low compression set of rubber.

Implementation Method 1

the radical initiator generates radicals upon light irradiation

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP3418037B1Rubber composition for three-dimensional additive manufacturing
Publication Date: 2021.07.28 SUMITOMO RUBBER INDUSTRIES LTD
  • EP3418037B1 patent drawingFigure 1(a)~1(b)
  • EP3418037B1 patent drawingFigure 2(a)~2(b)
  • EP3418037B1 patent drawing

AI summary

There is provided a rubber composition for additive manufacturing that allows rubber shaped articles to be favorably produced using an additive manufacturing apparatus. The rubber composition for additive manufacturing of the present invention comprises a liquid rubber.