Thin Plastic Auto Parts Coating for Cold Impact Resistance
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Solution Overview
Problem
Thinner plastic automobile parts lack sufficient impact resistance, especially at low temperatures, which hinders weight reduction and fuel efficiency improvements.
Innovation Solution
A multilayer coating film is applied to a polypropylene resin composition modified with an elastomer, comprising a primer coating composition, a base coating composition with a coloring agent, and a clear coating composition containing a crosslinked acrylic resin with polyfunctional and monofunctional monomers, providing enhanced impact resistance at -30°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the plastic product is made thinner for weight reduction, then the weight of the automobile part is reduced, but the strength and impact resistance deteriorate
Solution Approach 1:
The patent applies composite materials by combining polypropylene resin with elastomer components (ethylene-propylene rubber, butyl rubber, or acrylic rubber) to create a modified resin composition. This composite structure provides both the weight reduction benefits of thin plastic parts and the enhanced impact resistance needed for cold region usage, directly resolving the contradiction between thickness reduction and strength maintenance.
Solution Approach 2:
The patent changes the chemical and physical parameters of the base resin by incorporating specific elastomer components at controlled ratios (5-50 parts by weight per 100 parts of polypropylene resin). This parameter modification transforms the resin's low-temperature impact properties, enabling thin parts to maintain sufficient strength at -30°C and below without increasing thickness.
2Use of energy by moving object
If the plastic product is made thinner for weight reduction, then the fuel efficiency is improved, but the adaptability to harsh cold environments deteriorates
Solution Approach 1:
By creating a composite resin system combining polypropylene with specific elastomers, the patent enables thin-walled parts to function reliably in extreme cold (-30°C or lower) while maintaining the weight reduction necessary for improved fuel efficiency. The elastomer component provides the cold-temperature adaptability that pure polypropylene lacks.
Solution Approach 2:
The patent modifies the resin's glass transition temperature and impact transition temperature through elastomer incorporation, changing the material's thermal and mechanical parameters to ensure adaptability to harsh cold environments while keeping the part thickness reduced for fuel efficiency benefits.
3Strength
If a coating film is formed to improve impact resistance, then the impact resistance is enhanced, but the device complexity and manufacturing process increase
Solution Approach 1:
Instead of applying a separate coating film to the entire part, the patent incorporates impact-resistant elastomer components directly into the resin composition itself. This creates localized impact resistance throughout the material matrix, eliminating the need for additional coating processes and reducing manufacturing complexity while maintaining enhanced impact resistance.
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 enhances impact resistance of thin plastic automobile parts at low temperatures, reducing weight and improving fuel efficiency while maintaining gasohol resistance.
Implementation Method 1
a crosslinked acrylic resin (c-2) containing 2 to 30 parts by weight of polyfunctional monomer (c-2-1) with 2 to 4 radically polymerizable unsaturated groups per a molecule
Implementation Method 2
a crosslinked acrylic resin (c-2) containing 2 to 30 parts by weight of polyfunctional monomer (c-2-1) with 2 to 4 radically polymerizable unsaturated groups per a molecule and 98 to 70 parts by weight of monofunctional monomer (c-2-2) with one polymerizable unsaturated group
Implementation Method 3
a polypropylene resin composition modified with an elastomer component
Implementation Method 4
the strength of the plastic product has a close relationship with the thickness thereof, and when the plastic product is made thinner, the strength thereof deteriorates
Implementation Method 5
a coating composition containing the resin particles
Implementation Method 6
obtained by evaporating a solvent from the coating liquid
Data Source
AI summary
The object of the present disclosure is to provide an automobile part capable of improving fuel consumption by weight reduction of the part because the impact resistance that can be sufficiently used even in cold regions can be given to a part made of a thinner plastic.An automobile part obtained by forming a coating film layer on a plastic material comprising a polypropylene resin composition modified with an elastomer component having a thickness of 1.5 to 2.5 mm,wherein said coating film layer is a multilayer coating film obtained by coating and baking the following coating compositions in this order;(a) a primer coating composition having a single film tensile elongation of 5 to 35% at −20° C.,(b) a base coating composition containing a coloring agent and,(c) a clear coating composition containing at least a linear acrylic polyol (c-1) with a hydroxyl value of 80 to 220 mgKOH/g, a crosslinked acrylic resin (c-2) containing 2 to 30 parts by weight of polyfunctional monomer (c-2-1) with 2 to 4 radically polymerizable unsaturated groups per a molecule and 98 to 70 parts by weight of monofunctional monomer (c-2-2) with one polymerizable unsaturated group as a constituent unit, and having a glass transition point of 70 to 120° C., and a curing agent (c-3), andwherein the coating film layer has a Dupont impact strength of 4.9 J or more at −30° C.