Ascorbic Acid Anti-Sagging Additive for Gypsum Board

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Solution Overview

Problem

Gypsum products are prone to sagging and deformation under humid conditions, leading to poor aesthetics and costly remediation, with existing anti-sagging additives either ineffective or increasing production costs by slowing down the setting of gypsum slurry.

Innovation Solution

Incorporating ascorbic acid or its derivatives as anti-sagging additives in the gypsum board composition, which comprises a compound with a specific chemical structure lacking carboxylate groups, improving the anti-deformation properties without affecting the setting of the gypsum slurry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional anti-sagging additives (boric acid, gallic acid, tartaric acid, phosphates) are used, then anti-sagging performance is improved, but setting time is prolonged and production cost increases

Engineering Contradiction:

Improveanti-sagging performanceVSAvoidsetting time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The invention changes the chemical structure parameter of the additive by selecting compounds with specific molecular weight ranges (50-500 Daltons) and functional groups (hydroxyl, ether, ester, but excluding carboxyl groups), which fundamentally alters how the additive interacts with gypsum crystallization, thereby achieving anti-sagging without retarding setting

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention employs simple, inexpensive compounds such as ascorbic acid and its derivatives as additives, replacing complex and costly conventional additives like phosphates and gallic acid, thereby reducing production cost while maintaining effective anti-sagging performance

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If conventional anti-sagging additives are used, then anti-sagging performance is improved, but production cost increases

Engineering Contradiction:

Improveanti-sagging performanceVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention optimizes the dosage parameter to a narrow range (0.01-5% by mass, preferably 0.1-1%), which minimizes material consumption and cost while achieving the required anti-sagging effect, avoiding the need for large quantities of expensive conventional additives

Inventive Principle:

Principle #35Parameter changes

3Strength

If gypsum products are used under high humidity conditions, then structural strength is maintained, but deformation (sagging) occurs

Engineering Contradiction:

Improvestructural strengthVSAvoiddimensional stability

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

The invention introduces organic compounds as intermediary substances that mediate between the gypsum matrix and water molecules, preventing water from disrupting the crystalline structure and causing sagging, while maintaining the structural integrity and strength of the gypsum product under humid conditions

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite material system combining gypsum with specifically selected organic compounds (molecular weight 50-500 Daltons, containing hydroxyl groups but excluding carboxyl groups), where the organic component enhances dimensional stability without compromising the inherent structural strength of gypsum

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 use of ascorbic acid significantly enhances the anti-sagging resistance of gypsum products, maintaining stability under high humidity conditions while being cost-effective and not impacting the setting time of the gypsum slurry, thus improving the quality and reducing remediation needs.

Implementation Method 1

the compound comprises no carboxylate groups... significantly enhances the anti-sagging resistance of gypsum products, maintaining stability under high humidity conditions

Methodology Applied

Scientific EffectAnti-sagging effect:

Implementation Method 2

a mixture of calcined gypsum (calcium sulfate hemihydrate and/or anhydrous calcium sulfate) and water is cast, where the calcined gypsum (plaster) is hydrated by water to form a solidified gypsum which comprises crystalline hydrated gypsum matrix (calcium sulfate dihydrate)

Methodology Applied

Scientific EffectHydration: Hydrates

Data Source

PatentUS10793472B2Anti-sagging gypsum product and a method to manufacture

Publication Date: 2020.10.06 SAINT GOBAIN PLACO SAS

AI summary

The present invention provides a composition, a gypsum board and their preparation method and the use of ascorbic acid as an anti-sagging additive in a gypsum board. Said gypsum board comprises set gypsum prepared from the composition; while said composition comprises hemi-hydrate gypsum, water and a compound comprisinggroup and no carboxylate groups. The set gypsum prepared from the said composition shows better anti-sagging or deformation resisting property. The gypsum board of the present invention is hardly distorted and has stronger stability even in the condition of high humidity, thus improve the quality of the gypsum board to meet the demands of the customer.