Flame-Resistant Absorber Paper Composition for Higher Tensile Strength

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Solution Overview

Problem

Existing flame-resistant papers for radio wave absorbers have low toughness, leading to frequent breakage during processing such as drying and slitting, and insufficient tensile strength, affecting producibility.

Innovation Solution

A flame-resistant paper composition containing pulp, aluminum hydroxide, guanidine phosphate, a binder, and a conductive substance, with specific mass percentages, and a production method involving wet papermaking and impregnation with guanidine phosphate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flame-resistant paper contains aluminum hydroxide and polyborate salt, then flame resistance is improved, but toughness deteriorates leading to breakage during processing

Engineering Contradiction:
Improveflame resistanceVSAvoidtoughness
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent uses a composite material system combining aluminum hydroxide (40-70 mass%) as the primary flame retardant with a specifically formulated binder (5-10 mass%) containing polyvinyl alcohol and carboxymethyl cellulose. This composite approach maintains flame resistance while the binder components work synergistically to improve toughness and prevent breakage during processing.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the content parameters of each component, specifically setting aluminum hydroxide at 40-70 mass%, guanidine phosphate at 10-20 mass%, and binder at 5-10 mass%. These parameter ranges are carefully controlled to balance flame resistance with mechanical strength, preventing the paper from becoming too brittle while maintaining fire safety.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If flame-resistant paper contains urethane resin, then flame resistance is improved, but tensile strength remains insufficient causing breakage under tension

Engineering Contradiction:
Improveflame resistanceVSAvoidtensile strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent employs a composite binder system containing polyvinyl alcohol (3-8 mass%) and carboxymethyl cellulose (2-5 mass%) rather than relying solely on urethane resin. This composite binder formulation provides both adequate flame resistance and sufficient tensile strength to prevent breakage during production processes.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent adjusts the binder content parameter to 5-10 mass%, with specific proportions of polyvinyl alcohol and carboxymethyl cellulose, to achieve the optimal balance between flame resistance and tensile strength. This parameter optimization ensures the paper can withstand tension during production without compromising fire safety.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If flame-resistant paper has low toughness, then flame resistance is maintained, but breakage occurs during drying and secondary processing reducing producibility

Engineering Contradiction:
Improveflame resistanceVSAvoidproducibility
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent optimizes multiple parameters simultaneously: aluminum hydroxide content (40-70 mass%), guanidine phosphate (10-20 mass%), and binder content (5-10 mass%). These coordinated parameter adjustments ensure the paper maintains flame resistance while achieving sufficient toughness to prevent breakage during drying and secondary processing operations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent enhances the local quality of the paper structure by incorporating specific binder components that locally reinforce the paper matrix at critical stress points. The polyvinyl alcohol and carboxymethyl cellulose create localized strengthening zones that prevent propagation of cracks during processing while maintaining overall flame resistance.

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 paper exhibits high tensile strength, reduced breakage during processing, and maintains excellent flame resistance, ensuring good producibility and effective radio wave absorption.

Implementation Method 1

Since these radio wave absorbers absorb radio waves by converting radio energy into thermal energy

Methodology Applied
Scientific EffectRadio wave absorption and energy conversion: Absorption (EM radiation)

Implementation Method 2

a binder containing polyvinyl alcohol and carboxymethyl cellulose in a specific proportion

Methodology Applied
Scientific EffectHydrogen bonding: Chemical Bonding

Data Source

PatentUS12359374B2Flame-resistant paper for radio wave absorber member and production method for same
Publication Date: 2025.07.15 TORAY INDUSTRIES INC

AI summary

An object of the present invention is to provide, in particular, flame-resistant paper for a radio wave absorber member, the flame-resistant paper being unlikely to break during the production process and having favorable producibility in addition to being suitable for a radio wave absorber member and having high flame resistance. The flame-resistant paper for a radio wave absorber member according to the present invention contains pulp, aluminum hydroxide, guanidine phosphate, a binder, and a conductive substance, in which the content of the pulp is 5 to 20 mass %, the content of the aluminum hydroxide is 40 to 70 mass %, the content of the guanidine phosphate is 10 to 20 mass %, the content of the binder is 5 to 10 mass %, and the content of the conductive substance is 0.1 to 12 mass %.