Ethylene-Propylene Copolymer Viscosity Additive Processing

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Solution Overview

Problem

The production of low molecular weight ethylene-propylene copolymers for lubricating oils faces challenges in maintaining form stability and productivity due to the presence of oil, which complicates the thermo-mechanical degradation process and requires high temperatures and long dissolution times, leading to reduced dimensional stability and increased recovery issues.

Innovation Solution

A process involving the use of small quantities of polyvinylarene/conjugated hydrogenated polydiene/polyvinylarene block copolymers combined with ethylene-propylene copolymers, subjected to high shear and high temperature conditions, with the addition of lubricating oil, to achieve molecular weight reduction and improved form stability, allowing for efficient production and recovery of oil-extended OCPs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If low molecular weight ethylene-propylene copolymers are produced for lubricating oils, then molecular weight reduction is achieved, but form stability deteriorates

Engineering Contradiction:
Improvemolecular weightVSAvoidform stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent combines ethylene-propylene copolymer with polyvinylarene/conjugated hydrogenated polydiene/polyvinylarene block copolymer to form a composite additive system. This composite structure allows the low molecular weight copolymer to maintain viscosity improvement function while the block copolymer component provides form stability, resolving the contradiction between molecular weight reduction and form stability maintenance.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If thermo-mechanical degradation process is used for molecular weight reduction, then molecular weight is reduced, but the presence of oil complicates the process and reduces degradation efficiency

Engineering Contradiction:
Improvemolecular weightVSAvoiddegradation efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent extracts the oil component from the degradation process by performing thermo-mechanical degradation on the copolymer separately, then combining the degraded product with lubricating oil afterward. This separation eliminates the negative effect of oil on degradation efficiency while still achieving the desired molecular weight reduction and oil extension functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

3Stability of the object's composition

If high temperatures and long dissolution times are used for dissolving solid OCPs, then dissolution is achieved, but productivity decreases and recovery issues increase

Engineering Contradiction:
Improvedimensional stabilityVSAvoiddissolution time
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent changes the molecular weight parameter of the ethylene-propylene copolymer to a lower range (10,000-100,000 g/mol), which fundamentally alters the dissolution characteristics. This parameter change enables faster dissolution times (3-7 hours instead of longer) while maintaining adequate dimensional stability, thereby improving productivity without sacrificing product quality.

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If small quantities of block copolymers are added to improve form stability, then form stability is improved, but the complexity of the system increases

Engineering Contradiction:
Improveform stabilityVSAvoidsystem complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies partial action by using small quantities (0.1-10% by weight) of block copolymer rather than large amounts. This partial addition is sufficient to provide the necessary form stability improvement while minimizing the increase in system complexity and maintaining cost-effectiveness.

Inventive Principle:
Principle #16Partial or excessive action

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 process results in oil-extended OCPs with maintained or improved form stability, enabling normal processing and recovery, and enhances the degradation efficiency, overcoming the limitations of traditional methods by reducing the negative effects of oil on the thermo-mechanical degradation process.

Implementation Method 1

subjected to high shear and high temperature conditions, with the addition of lubricating oil, to achieve molecular weight reduction

Methodology Applied
Scientific EffectShear degradation: Shear Stress

Implementation Method 2

The process involves the use of small quantities of polyvinylarene/conjugated hydrogenated polydiene/polyvinylarene block copolymers combined with ethylene-propylene copolymers, subjected to high shear and high temperature conditions

Methodology Applied
Scientific EffectThermo-mechanical degradation: Thermomechanical Effect

Implementation Method 3

The oil is preferably fed after being absorbed on the block copolymer and used with block copolymer/oil ratios which vary from 1 to 5

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP1984479B1Ethylene-propylene copolymers suitable for the modification of lubricating oils and process for the preparation thereof
Publication Date: 2013.04.03 VERSALIS SPA
  • EP1984479B1 patent drawingFigure 1
  • EP1984479B1 patent drawingFigure 2
  • EP1984479B1 patent drawingFigure 3

AI summary

Process for the preparation of viscosity index improver (V.I.I.) additives of lubricating oils which comprises a mixing treatment under high shear conditions of a composition comprising: (i) one or more EP(D)M polymers (ii) one or more polyvinylarene/ conjugated hydrogenated polydiene/polyvinylarene block copolymers; and (iii) lubricating oil, (ii) being present in a concentration of 1.5 to 20% by weight whereas (iii) is present in a concentration ranging from 1.5 to 45% by weight.