Macro defect free cement with improved moisture resistance

Patent metadata

Field	Value
Publication number	US-9850164-B2
Application number	US-201615347856-A
Country	US
Kind code	B2
Filing date	Nov 10, 2016
Priority date	Jan 30, 2015
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A cementitious composition may include polyvinyl alcohol, high alumina cement, water, a metallic coagent, a peroxide crosslinking initiator, and an organic acid retardant. A molded article may be manufactured from the cementitious composition by preparing a hydrogel pre-polymer blend of saponified polyvinyl alcohol acetate (PVAA) with greater than or equal to approximately 85% saponified PVAA, and water, mixing the hydrogel pre-polymer blend with high alumina cement (HAC) using a high shear mixing process, mixing in a metallic coagent and a peroxide crosslinking initiator, mixing in an organic acid retardant, and hot press molding the mixture.

First claim

What is claimed is:

1. A method of manufacturing a molded article made from a MDF cementitious composition, the method comprising:
preparing a hydrogel pre-polymer blend of saponified polyvinyl alcohol acetate (PVAA) with greater than or equal to about 85 % saponified PVAA, and water;
mixing the hydrogel pre-polymer blend with high alumina cement (HAC) using a high shear mixing process;
mixing in a metallic coagent and a peroxide crosslinking initiator, wherein the metallic coagent is selected from the group comprising: zinc diacrylate (ZDA), zinc monoacrylate (ZMA), zinc dimethacrylate (ZDMA), calcium diacrylate (CDA), aluminum triacrylate, and magnesium diacrylate;
mixing in an organic acid retardant selected from the group comprising: acetic acid, citric acid, tartartic acid, succinic acid, and polymeric acids; and
hot press molding the mixture.

2. The method of claim 1 , further including:
extruding the mixture to form the molded article; and
post curing the molded article at a temperature of approximately 90 degrees C. for approximately 24 hours.

3. The method of claim 1 , wherein the hydrogel pre-polymer blend is produced from a ratio of polymer to water in the range from approximately 100 parts of polymer to 75 to 150 parts of water.

4. The method of claim 1 , wherein the proportions of ingredients of the MDF cementitious composition by weight comprise:
90-110 parts polyvinyl alcohol;
150-250 parts water;
1200-3000 parts high alumina cement (HAC);
30-100 parts metallic coagent; and
3-30 parts peroxide crosslinking agent.

Assignees

• Caterpillar Inc

Inventors

• Amstutz Aaron K

Classifications

• C04B2103/0047

  as a mixture of nonomers and prepolymers or oligomers · CPC title

• C04B24/04

  Carboxylic acids; Salts, anhydrides or esters thereof · CPC title

• C04B2111/00301

  Non-porous materials, e.g. macro-defect free [MDF] products · CPC title

• C04B24/06

  containing hydroxy groups · CPC title

• C04B24/00

  Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers · CPC title