Paintable Polyolefin Articles Without Primer

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Solution Overview

Problem

There is a need for materials that can replace soft PVC in applications like toys and footwear, which are environmentally friendly, non-toxic, paintable without primers, and maintain a specific Shore A hardness, while avoiding phthalate plasticizers, halogen-containing polymers, and leachable styrene monomers.

Innovation Solution

Polyolefin compositions, specifically ethylene-alpha-olefin interpolymers with densities less than 0.91 g/cm3 and Shore A hardness of 50 to 95, which are free of phthalate-based plasticizers, halogen-containing polymers, and leachable styrene monomers, allowing for paintability without primers and using paints designed for SBS- or SEBS-type rubber-based compositions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If soft PVC is used to achieve paintability and desired Shore A hardness, then the article can be painted without primer and maintains hardness of 50-95, but the article contains phthalate plasticizers and halogen-containing polymer that are environmentally harmful and toxic

Engineering Contradiction:

Improvepaintability without primerVSAvoidphthalate plasticizer and halogen-containing polymer toxicity

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing soft PVC with polyolefin interpolymers containing specific amounts of alpha-olefin comonomer (5-20 mole percent). This parameter change eliminates phthalate plasticizers and halogen-containing polymers while maintaining the desired Shore A hardness of 50-95 and paintability without primer through the specific comonomer content range.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite polyolefin interpolymer materials comprising ethylene and alpha-olefin comonomer units. These composite materials combine the benefits of polyolefin base polymer with the properties introduced by alpha-olefin comonomer to achieve both environmental safety (no phthalates or halogens) and functional performance (paintability and hardness).

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If styrene-based rubbers (SBS, SEBS) are used to achieve paintability and desired Shore A hardness, then the article can be painted with acrylic-modified paint without primer, but the article contains leachable small polymeric units derived from styrene monomer that are toxic

Engineering Contradiction:

Improvepaintability with acrylic-modified paintVSAvoidleachable styrene monomer units

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition by replacing styrene-based rubbers with polyolefin interpolymers containing alpha-olefin comonomer units. This parameter change eliminates leachable styrene monomer units while maintaining paintability with acrylic-modified paints and achieving the desired Shore A hardness through the specific comonomer content of 5-20 mole percent.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the problematic styrene-based rubber materials with polyolefin interpolymer materials that are safer and more environmentally friendly. The polyolefin base provides a safe, non-leachable alternative to styrene-containing materials while achieving the same functional goals.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If polyolefin elastomers (EP, EPDM) are used to eliminate leachable styrene monomer units, then the article is free of toxic substances, but the article requires primer or surface treatment for painting which increases time and cost

Engineering Contradiction:

Improveelimination of leachable styrene monomer unitsVSAvoidpaintability without primer

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent changes the chemical composition parameters by incorporating specific amounts of alpha-olefin comonomer (5-20 mole percent) into the polyolefin interpolymer. This parameter change enables the material to be painted without primer while maintaining freedom from leachable styrene monomer units. The specific comonomer content range is critical to achieving both environmental safety and paintability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces local quality changes by incorporating alpha-olefin comonomer units at specific concentrations (5-20 mole percent) within the polyolefin interpolymer structure. This localized modification of the polymer chain structure creates specific surface properties that enable paint adhesion without primer, while the bulk material remains free of toxic substances.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8530019B2Painted polyolefin articles

Publication Date: 2013.09.10 DOW GLOBAL TECHNOLOGIES LLC

AI summary

Articles having a Shore A hardness of 50 to 95 and made from polyolefin compositions comprising an ethylene-alpha-olefin interpolymer (random or block or a mixture of the two) are paintable without the need for a primer or other surface treatment with paints free of phthalate-based plasticizer and designed to paint SBS- or SEBS-type rubber based compositions. These polyolefin compositions are free of (1) phthalate-based plasticizer, (2) halogen-containing polymer, and (3) leachable, small polymeric units derived from styrene monomer. In addition, the content of the alpha-olefin in the polyolefin composition is at least 9.7 mole percent.