Polypropylene Resin Composition with Hydrogenated Block Copolymers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Molded bodies of polypropylene resin compositions for packaging, apparel, and medical applications require a balance of flexibility, transparency, anisotropy, low stickiness, and low temperature impact resistance, which existing hydrogenated diene polymer and polypropylene resin compositions fail to achieve effectively.
Innovation Solution
A resin composition comprising specific amounts of polypropylene resin and hydrogenated block copolymers with defined configurations, including vinyl aromatic and conjugated diene units, and specific degrees of hydrogenation, crystallization peaks, and tan δ peaks, to enhance the balance of properties in molded bodies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hydrogenated diene polymer and polypropylene resin compositions are used, then chemical resistance and mechanical properties are maintained, but the balance among flexibility, transparency, anisotropy, low stickiness, and low temperature impact resistance is insufficient
Solution Approach 1:
The patent uses a composite resin composition comprising polypropylene resin (a) and hydrogenated block copolymer (b) with specific structural parameters. The hydrogenated block copolymer contains vinyl aromatic compound units (1-15 mass%) and conjugated diene compound units with specific hydrogenation degrees (80-100%), creating a multi-phase composite structure that simultaneously achieves flexibility, transparency, anisotropy control, low stickiness, and low temperature impact resistance.
Solution Approach 2:
The patent precisely controls critical parameters including the hydrogenation degree of conjugated diene units (80-100%), vinyl aromatic compound content (1-15 mass%), and molecular weight characteristics (Mw/Mn ratio). By optimizing these parameters, the resin composition achieves a balanced property profile that conventional single-parameter formulations cannot attain, resolving the contradiction between maintaining mechanical properties and achieving multiple performance requirements.
2Strength
If polypropylene resin is used for packaging applications, then chemical resistance is achieved, but flexibility and low temperature impact resistance are compromised
Solution Approach 1:
The hydrogenated block copolymer introduces local soft segments (hydrogenated conjugated diene blocks) within the polypropylene matrix. These localized soft phases act as impact modifiers and flexibility enhancers while the majority polypropylene structure maintains chemical resistance, achieving local property differentiation that resolves the contradiction between strength and flexibility.
Solution Approach 2:
The hydrogenated block copolymer serves as an intermediary phase between the rigid polypropylene matrix and the requirements for flexibility. Its amphiphilic structure with hydrophobic polypropylene-compatible segments and soft diene blocks allows it to mediate between the conflicting requirements of chemical resistance and flexibility, improving low temperature impact resistance without sacrificing chemical stability.
3Illumination intensity
If resin composition is optimized for transparency, then visual appearance is improved, but low stickiness and anisotropy control are affected
Solution Approach 1:
The patent controls the vinyl aromatic compound content at 1-15 mass% and hydrogenation degree at 80-100%, which optimizes the refractive index matching and phase distribution for maximum transparency. Simultaneously, these parameter changes control the surface energy and intermolecular forces to reduce stickiness, achieving a parameter set that satisfies both optical and tactile requirements.
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 resin composition achieves a superior balance of flexibility, transparency, anisotropy, low stickiness, and low temperature impact resistance in molded bodies, improving their performance in various applications.
Implementation Method 1
degrees of hydrogenation of the hydrogenated block copolymers (b) and (c) are each 80 mol% or more
Data Source
AI summary
The resin composition according to the present invention comprises a polypropylene resin (a), a hydrogenated block copolymer (b), and a hydrogenated block copolymer (c), wherein the hydrogenated block copolymers (b) and (c) comprise, in each molecule, a vinyl aromatic compound unit and a conjugated diene compound unit; a total amount of the vinyl aromatic compound unit in the hydrogenated block copolymers (b) and (c) is 1 to 15 mass%; degrees of hydrogenation of the hydrogenated block copolymers (b) and (c) are each 80 mol% or more; a butylene content and/or a propylene content in the hydrogenated block copolymers (b) and (c) is specified; a tan δ peak obtained by a dynamic viscoelasticity measurement (1 Hz) of the hydrogenated block copolymers (b) and (c) are each in a specified range; the hydrogenated block copolymer (b) and/or (c) has a crystallization peak at -20 to 80°C and has a heat of crystallization of 0.1 to 10 J/g; the hydrogenated block copolymers (b) and (c) neither have a crystallization peak at a position other than -20 to 80°C nor have a heat of crystallization of less than 0.1 J/g and more than 10 J/g;a mass ratio of a content of the hydrogenated block copolymer (b) to a content of the hydrogenated block copolymer (c), (b)/(c), is 90/10 to 10/90; and a mass ratio of a content of the polypropylene resin (a) to a total content of the hydrogenated block copolymer (b) and the hydrogenated block copolymer (c), (a)/((b) + (c)), is 10/90 to 90/10.