Fiber-Sizing Composition for Impact-Resistant Glossy Moldings

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Solution Overview

Problem

Thermoplastic and thermosetting resin compositions with inorganic reinforcing materials face challenges in maintaining high impact resistance and surface gloss properties, with existing solutions either reducing impact resistance or resulting in poor appearance.

Innovation Solution

A fiber-sizing agent comprising a modified olefin wax, an unmodified polyolefin resin, and a silane coupling agent, with a specific mass ratio and molecular weight range, is applied to inorganic reinforcing materials to enhance their dispersibility and sliding properties, thereby improving the impact resistance and surface gloss of molded articles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If inorganic reinforcing materials are incorporated to enhance stiffness and heat resistance, then mechanical properties are improved, but impact resistance deteriorates

Engineering Contradiction:
Improvestiffness and heat resistanceVSAvoidimpact resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent introduces a fiber-sizing agent as an intermediary substance that coats the inorganic reinforcing material surface. This sizing agent contains a specific composition including polypropylene resin, wax, and coupling agents that mediate between the inorganic reinforcing material and the thermoplastic resin matrix, improving interfacial adhesion and stress transfer while maintaining impact resistance

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent optimizes specific parameters of the fiber-sizing agent composition, including the molecular weight distribution of polypropylene resin (using both high and low molecular weight components), the ratio of wax to resin, and the type of coupling agent. These parameter changes enable the sizing agent to provide both stiffness enhancement and impact resistance

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If conventional fiber-sizing agents with small amounts of wax are used, then dispersibility is improved, but surface gloss properties deteriorate

Engineering Contradiction:
Improvedispersibility of inorganic reinforcing materialVSAvoidsurface gloss properties
Core Design Contradiction:
Stability of the object's compositionVSIllumination intensity

Solution Approach 1:

The patent changes the parameter of wax content in the fiber-sizing agent from conventional small amounts to a specific optimized range (0.1-5 mass% based on total sizing agent). It also changes the molecular weight distribution of the polypropylene resin by using a combination of high and low molecular weight resins, which improves both dispersibility and surface gloss properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The fiber-sizing agent is formulated as a composite material containing multiple components: polypropylene resin (both high and low molecular weight), wax, and coupling agents. This composite structure enables the sizing agent to simultaneously provide dispersibility enhancement and surface gloss improvement

Inventive Principle:
Principle #40Composite materials

3Reliability

If olefin wax with carboxyl groups is incorporated to improve impact resistance, then dispersibility is enhanced, but surface gloss properties deteriorate

Engineering Contradiction:
Improveimpact resistanceVSAvoidsurface gloss properties
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The patent changes the parameter of wax molecular weight to a specific low range (300-3000 number average molecular weight), which is significantly lower than conventional waxes. This parameter change allows the wax to provide impact resistance enhancement without adversely affecting surface gloss properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different molecular weight components of polypropylene resin to different functions: high molecular weight resin provides structural integrity and stiffness, while low molecular weight resin improves surface properties and gloss. This local quality differentiation resolves the contradiction between impact resistance and surface appearance

Inventive Principle:
Principle #3Local quality

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 proposed solution effectively enhances the impact resistance and surface gloss of molded articles by improving the dispersibility and sliding properties of inorganic reinforcing materials within the resin composition, addressing the limitations of existing technologies.

Implementation Method 1

a silane coupling agent (C), wherein a mass ratio (A)/(B) of the modified olefin wax (A) to the unmodified polyolefin resin (B) is in the range of 0.2 to 10

Methodology Applied
Scientific EffectChemical adhesion: Adhesive

Implementation Method 2

A small amount of wax is incorporated in a fiber-sizing agent for imparting lubricity

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 3

an inorganic reinforcing material is coated with a fiber-sizing agent for developing the sizing properties of the inorganic reinforcing material and the dispersibility of the inorganic reinforcing material in resin during molding

Methodology Applied
Scientific EffectSurface coating: Coatings

Data Source

PatentEP3677639B1Fiber-sizing agent, inorganic reinforcement material, resin composition, and molded article
Publication Date: 2023.11.15 MITSUI CHEMICALS INC

AI summary

The purpose of the present invention is to provide a fiber-sizing agent which when applied to an inorganic reinforcement material contained in a resin composition, can provide a molded article having excellent impact resistance and high surface gloss properties. The fiber-sizing agent according to the present invention contains a modified olefin wax (A), a polyolefin resin (B), and a silane-coupling agent (C), wherein the mass ratio (A)/(B) of the modified olefin wax (A) to the polyolefin resin (B) is in the range of 0.2-10.