PBT Polyester Composition for Laser Welding and Low RF Loss

Solution Overview

Problem

Existing polyester materials have low transmittance to laser beams and high electromagnetic wave transmission loss, limiting their application in laser welding and high-frequency communications.

Innovation Solution

A polyester composition comprising PBT resin with a specific SAXS spectrum slope within the range of −2.00 to −4.20, enhancing laser transmittance and reducing electromagnetic wave transmission loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional polyester materials are used, then good mechanical properties and formability are achieved, but low laser transmittance and high electromagnetic wave transmission loss occur

Engineering Contradiction:

Improvelaser transmittanceVSAvoidelectromagnetic wave transmission loss

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by controlling the SAXS spectrum slope within the range of -2.00 to -4.20 at specific scattering vectors (0.15-0.20 nm⁻¹). This parameter control modifies the molecular structure and crystalline phase of the PBT resin, resulting in improved laser transmittance (30-70% at 1064 nm wavelength) and reduced electromagnetic wave transmission loss (dielectric constant 2.5-3.5, dissipation factor 0.005-0.015 at 40 GHz).

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining PBT resin with specific additives including nucleating agents (0.1-5.0 wt%), antioxidants (0.05-2.0 wt%), and processing aids (0.05-1.0 wt%). This composite formulation achieves both high laser transmittance and low electromagnetic wave transmission loss while maintaining good mechanical properties and processability.

Inventive Principle:

Principle #40Composite materials

2Adaptability or versatility

If conventional polyester materials are used, then good chemical stability is achieved, but limited application flexibility in laser welding and high-frequency communications occurs

Engineering Contradiction:

Improveapplication flexibilityVSAvoidlaser welding suitability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies parameter changes by controlling the SAXS spectrum slope within the range of -2.00 to -4.20 at specific scattering vectors (0.15-0.20 nm⁻¹). This parameter control modifies the molecular structure and crystalline phase of the PBT resin, resulting in improved laser transmittance (30-70% at 1064 nm wavelength) and reduced electromagnetic wave transmission loss (dielectric constant 2.5-3.5, dissipation factor 0.005-0.015 at 40 GHz).

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining PBT resin with specific additives including nucleating agents (0.1-5.0 wt%), antioxidants (0.05-2.0 wt%), and processing aids (0.05-1.0 wt%). This composite formulation achieves both high laser transmittance and low electromagnetic wave transmission loss while maintaining good mechanical properties and processability.

Inventive Principle:

Principle #40Composite materials

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 improved polyester composition exhibits higher total transmittance under near-infrared light, lower dielectric constants, and lower dissipation factors, making it suitable for applications in vehicles, communications, aerospace, and medical industries.

Implementation Method 1

the polyester composition of the instant disclosure can have an improved laser transmittance... the polyester composition and/or the molded products thereof of the instant disclosure have a higher total transmittance under the near infrared light

Methodology Applied

Scientific EffectLaser transmittance:

Implementation Method 2

the polyester composition and/or the molded products thereof of the instant disclosure have lower dielectric constants and/or dissipation factor

Methodology Applied

Scientific EffectElectromagnetic wave transmission:

Implementation Method 3

The polyester composition is analyzed by small angle X-ray scattering (SAXS) to obtain a spectrum with a vertical axis representing scattering intensity and a horizontal axis representing scattering vector

Methodology Applied

Scientific EffectX-ray scattering: Scattering

Data Source

PatentUS20250163262A1Polyester composition and its molded product

Publication Date: 2025.05.22 CHANG CHUN PLASTICS CO LTD

AI summary

Provided are a polyester composition and its product. The polyester composition comprises polybutylene terephthalate resin and is analyzed by small angle X-ray scattering (SAXS) to obtain a spectrum with the vertical axis representing scattering intensity and the horizontal axis representing scattering vector. A slope of the SAXS spectrum ranges from −2.00 to −4.20 within the scattering vector ranging from 0.15 nm−1 to 0.20 nm−1. The polyester composition with the foresaid features can have improved laser transmittance and low electromagnetic wave transmission loss, thereby enhancing the value of plastic products joined by laser welding.