Hydraulic fixing agent and method for reducing the cohesion of a layer of bonded fixing agent

• US 6,998,012 B2
• Filed: 11/19/2003
• Issued: 02/14/2006
• Est. Priority Date: 11/20/2002
• Status: Expired due to Fees

• Current Assignee: Akzo Nobel N.V. (Nouryon BV)
• Original Assignee: National Starch and Chemical Investment Holding Corporation
• Inventors: Koelliker, Robert, Zemp, Josef
• Primary Examiner(s): Fiorilla, Christopher A.
• Assistant Examiner(s): CHAN, SING P
• Application Number:
  US10/716,648
• Publication Number:
  US 20040137151A1
• Time in Patent Office: 818 Days
• Field of Search: 134/2, 134/22.13, 134/22.14, 134/22.16, 134/22.17, 134/22.19, 134/26, 134/38, 134/42, 134/155, 427/258, 427/270, 427/271, 427/273, 427/307, 427/336, 427/337, 427/419.1, 427/419.7, 427/419.8, 156/344
• US Class Current: 156/703
• CPC Class Codes: C04B 14/06 Quartz; Sand
• CPC Class Codes: C04B 14/20 Mica; Vermiculite mechanical splitting B28D
• CPC Class Codes: C04B 14/28 of calcium
• CPC Class Codes: C04B 2103/004 according to DIN
• CPC Class Codes: C04B 2111/00482 Coating or impregnation materials
• CPC Class Codes: C04B 2111/00612 as one or more layers of a layered structure
• CPC Class Codes: C04B 22/147 Alkali-metal sulfates; Ammonium sulfate
• CPC Class Codes: C04B 24/06 containing hydroxy groups
• CPC Class Codes: C04B 24/2623 Polyvinylalcohols; Polyvinylacetates
• CPC Class Codes: C04B 24/383 Cellulose or derivatives thereof
• CPC Class Codes: C04B 28/065 Calcium aluminosulfate cements, e.g. cements hydrating into ettringite
• CPC Class Codes: C04B 40/0028 Aspects relating to the mixing step of the mortar preparation
• CPC Class Codes: C04B 40/0092 Temporary binders, mortars or concrete, i.e. materials intended to be destroyed or removed after hardening, e.g. by acid dissolution
• CPC Class Codes: C04B 41/53 involving the removal of at least part of the materials of the treated article, e.g. etching, drying of hardened concrete C04B41/0036 - C04B41/0054 take precedence
• CPC Class Codes: C04B 7/02 Portland cement
• CPC Class Codes: Y10T 156/1111 Using solvent during delaminating [e.g., water dissolving adhesive at bonding face during delamination, etc.]

Abstract

Hydraulic fixing agent that is based on Portland cement, a sulphate and aluminum component that is usual in this system, and optionally other additives. This is characterized in that, according to DIN 18156 (Part 2, Sec. 5.2.2.2, 5.2.2.3a) and 5.2.2.4), the hydraulic fixing agent has (1) an adhesive pull strength of at least approximately 0.15 N/mm² when acted upon by water for 40 hours and (2) an adhesive pull strength of at most approximately 0.10 N/mmyy2 when acted upon by an aqueous sulphate solution and/or an aqueous solution of an aluminum salt, each of which has a pH value of 12.5, for a period of 40 hours.

Claims

1. A method for reducing the cohesion of a layer of bonded fixing agent, obtained with an hydraulic fixing agent that is based on Portland cement, a sulphate and aluminum component, and optionally other additives, wherein the hydraulic fixing agent, has (1) an adhesive pull strength of at least approximately 0.15 N/mm² when acted upon by water for 40 hours and (2) an adhesive pull strength of at most approximately 0.10 N/mm² when acted upon by an aqueous sulphate solution and/or an aqueous solution of an aluminum salt, each with a pH value of 12.5, for 40 hours, characterized in that the layer of bonded fixing agent is treated with an aqueous sulphate solution and/or an aqueous solution of an aluminum salt, each of which has a pH of at least approximately 7.5 and the layer of bonded fixing agent with its cohesion reduced is removed.

2. The method as defined in claim 1, characterized in that a water-soluble alkali, earth alkali sulphate or mixture of alkali and earth alkali sulphate is used as the aqueous sulphate solution and/or a water-soluble alkali or earth alkali aluminate is used as the aqueous solution of an aluminum salt.

3. The method as defined in claim 1, characterized in that the aqueous sulphate solution is used in a concentration of approximately 0.1 to 30%-wt, and the aqueous solution of the aluminum salt is used in a concentration of approximately 0.1 to 70%-wt.

4. The method as defined in claim 3, characterized in that the aqueous sulphate solution is used in a concentration of from approximately 1 to 20%-wt.

5. The method as defined in claim 3, characterized in that the aqueous solution of the aluminum salt is used in a concentration of from approximately 1 to 50%-wt.

6. The method as defined in claim 1, characterized in that the layer of bonded fixing agent is sprayed with the aqueous sulphate solution and/or the aqueous solution of an aluminum salt.

7. The method as defined in claim 1, characterized in that incorporated in the layer of bonded fixing agent there is a textile material that is brought into contact with the aqueous sulphate solution or the aqueous solution of an aluminum salt, in order to moisten the interior of the layer of bonded fixing agent.

8. The method as defined in claim 7, characterized in that a fabric or a non-woven textile is used as textile material.

9. The method as defined in claim 7, characterized in that the textile material has a water absorbency (as measured according to DIN 53923, dated January 1978) of approximately 1 to 5000%-wt, and/or a tear resistance (as measured according to DIN 53857) of approximately 5 to 1000 N/5 cm.

10. The method as defined in claim 7, characterized in that the textile material is hydrophilic.

11. The method as defined in claim 10, characterized in that the textile material is selected from the group consisting of cellulose, cellulose acetate, cotton, hemp, jute, sisal, flax, plastics, surface coated microfibres, uncoated microfibres and mixtures thereof.

12. The method as defined in claim 1, characterized in that a covering layer is formed on the layer of bonded fixing agent.

13. The method as defined in claim 12, characterized in that the covering layer is formed in the form of ceramic tiles;

plastic, glass, metal or wood panels;

colour coatings;

textile materials, or mixtures thereof.

14. The method as defined in claim 12, characterized in that once the cohesion has been reduced, the layer of bonded fixing agent is removed from a subsurface that is optionally bonded to the covering layer.

15. The method as defined in claim 1, characterized in that the aqueous sulphate solution or the aqueous solution of the aluminum salt acts on the layer of bonded fixing agent for at least approximately five hours.

16. The method as defined in claim 15, characterized in that the aqueous sulphate solution or the aqueous solution of the aluminum salt acts on the layer of bonded fixing agent for approximately 12 to 48 hours.

17. The method as defined in claim 1, wherein the pH is in the range of approximately 9 to 14.