Chloroprene Polymer Composition Balancing Flexibility and Breaking Strength

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Solution Overview

Problem

Chloroprene polymer compositions used in dip-molded articles face a trade-off between mechanical properties and flexibility, and the use of sulfur and vulcanization accelerators leads to adverse health effects and increased costs, necessitating a method to achieve flexibility and breaking strength without these components.

Innovation Solution

A method involving polymerization of chloroprene in the presence of rosin acid components, with specific mass ratios and toluene insoluble content, to produce a chloroprene polymer composition that enhances flexibility and breaking strength without sulfur and vulcanization accelerators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If sulfur and vulcanization accelerator are used to enhance mechanical properties, then breaking strength is improved, but health safety deteriorates due to type IV allergy reactions

Engineering Contradiction:
Improvebreaking strengthVSAvoidhealth safety
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and removes sulfur and vulcanization accelerators from the chloroprene polymer composition. By eliminating these harmful substances while maintaining breaking strength through optimized polymerization conditions and rosin acid component selection, the patent resolves the contradiction between mechanical properties and health safety.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the chemical composition parameters by controlling the mass ratio B1/A1 of specific rosin acid components (abietic acid, neoabietic acid, palustric acid, levopimaric acid and their salts) to dehydroabietic acid, pimaric acid, isopimaric acid, dihydroabietic acid and their salts within 0.10 to 3.00. This parameter optimization enables achieving breaking strength without sulfur and vulcanization accelerators.

Inventive Principle:
Principle #35Parameter changes

2Strength

If sulfur and vulcanization accelerator are used to improve mechanical properties, then breaking strength is enhanced, but manufacturing cost increases

Engineering Contradiction:
Improvebreaking strengthVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention removes sulfur and vulcanization accelerators from the manufacturing process, eliminating the need to purchase and handle these expensive additives. The cost reduction is achieved while maintaining breaking strength through optimized polymerization conditions and rosin acid component ratios.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive sulfur and vulcanization accelerator systems with a cost-effective approach using naturally occurring rosin acid components from pine trees. This substitution reduces raw material costs while achieving the desired mechanical properties through proper formulation and processing.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Strength

If chloroprene polymer composition is optimized for mechanical properties, then breaking strength is improved, but flexibility deteriorates

Engineering Contradiction:
Improvebreaking strengthVSAvoidflexibility
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The invention optimizes multiple parameters simultaneously: the mass ratio B1/A1 of rosin acid components is controlled within 0.10 to 3.00, and the toluene insoluble content is maintained at 50% by mass or more. These parameter changes enable achieving both high breaking strength and good flexibility by balancing cross-linking density and polymer chain mobility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite effect by combining chloroprene polymer with specific rosin acid components (abietic acid, neoabietic acid, palustric acid, levopimaric acid and their salts) in optimized ratios. This composite approach provides both the strength from cross-linking and the flexibility from the natural rosin acid structures.

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 method enables the production of dip-molded articles with excellent flexibility and breaking strength, reducing health risks and costs while maintaining mechanical properties.

Implementation Method 1

a polymerization step of polymerizing chloroprene in the presence of at least one rosin acid component selected from the group consisting of a rosin acid and a rosin acid salt to obtain a chloroprene polymer

Methodology Applied
Scientific EffectPolymerization:

Implementation Method 2

a mass ratio B1/A1 of a total amount B1 of abietic acid, neoabietic acid, palustric acid, levopimaric acid, and salts thereof with respect to a total amount A1 of dehydroabietic acid, pimaric acid, isopimaric acid, dihydroabietic acid, and salts thereof is 0.10 to 3.00, and a toluene insoluble content of the chloroprene polymer is 50% by mass or more

Methodology Applied
Scientific EffectCross-linking:

Data Source

PatentUS12577381B2Chloroprene polymer composition, manufacturing method therefor, and dip-molded article
Publication Date: 2026.03.17 DENKA CO LTD

AI summary

A method for manufacturing a chloroprene polymer composition, the method including: a polymerization step of polymerizing chloroprene in the presence of at least one rosin acid component selected from the group consisting of a rosin acid and a rosin acid salt to obtain a chloroprene polymer composition containing a chloroprene polymer, in which in the rosin acid component, a mass ratio B1/A1 of a total amount B1 of abietic acid, neoabietic acid, palustric acid, levopimaric acid, and salts thereof with respect to a total amount A1 of dehydroabietic acid, pimaric acid, isopimaric acid, dihydroabietic acid, and salts thereof is 0.10 to 3.00, and a toluene insoluble content of the chloroprene polymer is 50% by mass or more.