CN109996740B

CN109996740B - Package for delivering additives for powdered compositions

Info

Publication number: CN109996740B
Application number: CN201780070218.6A
Authority: CN
Inventors: J·D·谢尔登; N·L·伯尼克-格鲁辛; J·F·格鲁辛; S·C·爱莫迪诺; T·金凯德; C·米勒
Original assignee: United States Gypsum Co
Current assignee: United States Gypsum Co
Priority date: 2016-11-28
Filing date: 2017-11-22
Publication date: 2022-04-15
Anticipated expiration: 2037-11-22
Also published as: JP2020500786A; CO2019006215A2; KR20190088995A; AU2017363242A1; EP3544907A1; RU2019117043A; BR112019008876A2; CA3044836A1; PH12019501073A1; MY195640A; CN109996740A; RU2019117043A3; PE20190769A1; WO2018098263A1; CL2019001261A1; MX2019005346A

Abstract

A joint compound system (10) is provided that includes a main container (12) of a base joint compound; and an additive container (28) isolated from the base-binding agent and containing at least one and preferably a plurality of additive packages (30) constructed and arranged such that the additive packages are protected from exposure to moisture prior to final mixing thereof with the base-binding agent.

Description

Package for delivering additives for powdered compositions

Background

The present invention relates generally to multi-component powdered compositions, and more particularly to packaging additives for curable powder compositions, such as, but not limited to, wallboard cement.

Walls and ceilings made of gypsum wallboard are typically constructed by attaching wallboard panels to framing members or studs and filling and coating the joints between the panels with a specially formulated paste composition called a joint compound. The binding agent may be provided as a powdered composition (to be mixed with water at the worksite) or may be pre-mixed with water at the factory to produce a pre-mixed (or paste-like) binding agent. A paste cement (adhesive sealing grade) is placed in and on the seam formed by the abutting edges of the wallboard panels, and a paper reinforcing tape is embedded in the seam with the cement and then allowed to dry. Alternatively, the reinforcing tape may have a non-cellulosic composition, but be similar in size and shape to the paper joint tape strips. Alternatively, the reinforcing tape may have a woven glass fiber fabric, which requires the use of a chemically curable binder. When the joint compound dries, a second joint compound (top or finishing grade) is applied over the joint and is also allowed to dry. A third application of the bonding agent is usually required and after the third application is dried, it can be lightly sanded and can be finished, usually with decorative material (paint, texture or wallpaper) and then applied to the wall. Alternatively, All three cement coatings can be used with All common grade (All pure cement grade) cements.

There are many classes of bonding agents. The drying type compound is hardened by evaporation of water, and the curing type bonding agent chemically reacts with water during the curing process. Setting cements typically use calcium sulfate hemihydrate (also known as stucco or plaster of Paris) as a base. When water is added to the setting type powder, it reacts with the calcium sulfate hemihydrate through a hydration reaction to form an interlocking matrix of calcium sulfate dihydrate crystals. Interlocking the crystalline matrices increases the strength of the compound. The benefits of a cured joint compound over a dried one are the overall strength of the finished joint, resulting in less shrinkage and cracking, and the need to wait for the joint compound to completely dry before further finishing. Dry cements have the advantage of being easy to use, as they are typically present in a pre-mixed form, where water is added and mixed by the manufacturer. The third type of cement combines the setting action of calcium sulfate hemihydrate-like compounds with the ease of use of pre-mixed compounds.

The pre-mixed joint compound is typically supplied to the customer in cartons or plastic drums in units having a volume of 3.5 to 4.5 gallons (13.25-17.03L). The joint compound is typically supplied at a viscosity higher than the viscosity applied at the worksite. This allows the contractor to mix in additional water using a power drill and mixing paddles to achieve the desired application viscosity.

Premix joint production is typically accomplished by blending the wet and dry ingredients in the mixture until smooth, adjusting the viscosity to the desired level by adding water, and then filling and sealing the container for shipment to the customer. This process can be broken by using ingredients that thicken very quickly and take longer to fully wet and reduce viscosity, passing the combined wet and dry ingredients in the mixer through a typical mixing cycle and competing for water at a higher viscosity than desired. The above process leads to mechanical limitations and problems such as binding of the wet mixer and overloading of the mixer motor. Higher than desired viscosity at the completion of the mixing cycle affects the ease of pumping and moving the materials out of the mixing system and through the packaging line, and also interferes with the capping and closing of the containers.

It is well known to provide selective performance enhancing additives to cement mixtures during job site formulation to enhance performance characteristics. In some cases, the curing or drying time is accelerated, while in other cases it is delayed. Furthermore, viscosity and/or dust generation during sanding are characteristics that are affected by the mixture additives. Therefore, there are mechanical limitations to the types of raw materials that can be used in a typical wet mixing system for making the premix. Depending on specific product requirements, including shelf life prior to long-term use, rapid cure, low viscosity applications, and other requirements, several options have been proposed to provide the cement with individual additives that enable the user to obtain enhanced or more desirable cement performance characteristics when the mixture is completed prior to application.

U.S. patent No. 6,476,099, incorporated herein by reference, discloses the addition of surfactant additives to cements to produce a cement having improved properties of cracking, improved shrinkage, and defects that reduce surface finish after application to the surface of the wallboard. U.S. patent nos. 6,228,163 and 5,746,822, incorporated herein by reference, disclose cements formulated with base cements that are relatively inert until additional additives are provided that functionally act as activators.

U.S. patent No. 8,822,566, incorporated herein by reference, discloses providing a heterogeneous formulation of additives with a pre-mixed base-cement that is ultimately mixed by a user of a worksite. There is a continuing need to provide additives in a form that enables a user to adjust the operational characteristics of the bonding agent to suit a particular situation

Disclosure of Invention

The additive packaging system of the present invention meets the above identified need by providing an individually packaged additive for use with a base cement or other powder or curable composition in a primary container so that a user can adjust the characteristics of the cement or desired composition during mixing. In a preferred embodiment, the small flexible package in the form of a tear-away pouch or stick pack contains a specified amount of additive for a drywall finish product that allows the user to add the additive to obtain the desired shape or characteristic in the resulting joint compound. Such packaging allows for pre-dispensing small amounts of additives that can be easily distributed to consumers, enabling them to add the additives to drywall finishing products, such as cements, drywall repair compounds, gypsum, and the like, to achieve any desired shape. Preferred additives provided in the packages of the present invention include, but are not limited to, colorants, dedusting agents, binders, pigments, adhesion promoters, activators, accelerators, retarders, thickeners, and the like as known in the art.

In one embodiment, the individual additive packages are water soluble such that when a user drops the package into the main container of the base joint compound, the package dissolves and becomes part of the mixture. It is also contemplated to provide individual packages containing fully formulated binding agents in a powdered formulation. A preferred material for the package is water-soluble polyvinyl alcohol; however, other water-soluble plastics are contemplated, provided that they are completely water-soluble at room temperature. The packaged additive may be in the form of a liquid, solid or powder.

Another feature of the system of the present invention is to provide the additive to the user in relatively small volume doses, desirably in small batches of cement for small wall repair operations or the like. Yet another feature of the system of the present invention is that multiple relatively small volume packages of the same additive are also contemplated. For example, in the case of an accelerator, for a given batch of bonding agent, the user adds multiple accelerator packages to achieve a relatively faster cure of the finished mixed bonding agent.

The system of the present invention includes a main vessel of base cement, which is a powder or a premix. In addition, a separate container contains at least one and preferably a plurality of water-soluble additive packages such that the additive packages are protected from exposure to moisture prior to their final mixing. Also included in the system of the present invention is a flexible package containing a supply of additives.

More specifically, a cement system is provided, comprising

A main container of base joint compound; and an additive container isolated from the base-binding agent and containing at least one and preferably a plurality of additive packages constructed and arranged such that the additive packages are protected from exposure to moisture prior to final mixing thereof with the base-binding agent. In one embodiment, the base binder is a powder or a premix. In another embodiment the main container has a removable lid and the additive container is located on the lid and the additive container is also located on the underside of the lid. Alternatively, the additive container is provided with a frangible wall.

In one embodiment, the additive package is encapsulated in a water soluble material, preferably polyvinyl alcohol. Furthermore, the additives are preferably selected from retarders, accelerators, activators, pigments, adhesion promoters and dust reducers. In the latter embodiment, at least one additive package is a plurality of packages, each of said packages containing one of the same or different additives as other of said packages in said plurality of packages.

In one embodiment, the additive comprises in the range of 5 to 20 grams of additive, and more preferably 10 grams of additive.

In another embodiment, a joint compound system is provided that includes a main container of a base joint compound; a separate container, distinct from the main container, and containing at least one and preferably a plurality of water-soluble additive packages constructed and arranged such that the additive packages are protected from exposure to moisture prior to their final mixing with the base joint compound; the additive package is enclosed in water-soluble polyvinyl alcohol; said at least one additive package is a plurality of packages, each of said packages containing one of the same or different additives as other of said packages in said plurality of packages; and the additive comprises in the range of 5 to 20 grams of additive, more preferably 10 grams of additive.

Drawings

FIG. 1 is a vertical cross-section of an additive system of the present invention;

FIG. 2 is an exploded vertical cross-section of the system of the present invention showing an additive package added to a primary cement container;

FIG. 3 is an exploded vertical cross-section of the system of the present invention showing the mixing of an additive package into a cement;

FIG. 4 is a vertical cross-section of an alternative embodiment of the additive system of the present invention using a separate container for the additive package;

FIG. 5 is a vertical cross-section of the embodiment of FIG. 4 showing mixing of the additive package into the primary joint compound container; and is

Figure 6 is a flexible package suitable for use in the system of the present invention.

Detailed Description

Referring to fig. 1-3, a water soluble additive system of the present invention is shown generally at 10 and includes an individually packaged additive for use with a base cement or other powder or curable composition in a master container so that a user can adjust the characteristics of the cement or desired composition during mixing. More specifically, the main container 12 is typically a plastic tub or tank of the type used for packaging pre-mixed wallboard joint compound, and includes a bottom 14, an annular sidewall 16, and an upper lid 18, all of which are integrally formed, such as by being made of molded plastic and bonded to define an interior chamber 20. Other materials are contemplated for the container 12, including but not limited to metal and paperboard. The supply of pre-mixed cement 22 substantially fills the internal chamber 20. While in the preferred embodiment, the base cement 22 is a pre-mixed type, it is also contemplated that a powder or setting type cement may be suitable.

The interior chamber 20 is covered by a removable container lid 24 that engages the upper lid 18 and latch closed on the main container 12 using plastic clips or connectors (not shown) on the exterior of the container as is known in the art. It is a feature of the present system 10 that the underside 26 of the container lid 24 is provided with a compartment or additive container 28, the compartment or additive container 28 being constructed and arranged to hold at least one, and preferably a plurality of

Individual additive packages 30. The additive container 28 is preferably made of the same material as the lid 24 and is configured to isolate the additive package 30 from the base cement 22 and the internal chamber 20 prior to use and to be protected from exposure to moisture prior to final mixing of the additive package with the cement 22. Individually packaged contemplated additives 32 suitable for use in the water-soluble additive package 30 of the present invention include, but are not limited to, retarders, accelerators, activators, dust reducers, pigments, adhesion promoters, such as powdered binders, including polyvinyl alcohol or polyvinyl acetate and the like. It is contemplated that the state of the packaged additive 32 is liquid, solid, or powder.

The lower wall 34 of the additive container 28 is frangible, such as by scoring, perforating, having a relatively thin wall thickness, or the like. Thus, when a user of the joint compound 22 in the master container 12 is ready to apply the joint compound, the user using a tape knife or similar tool easily breaks the frangible walls 34, and once the walls are broken, the additive package 30 falls into the joint compound 22 (FIG. 2).

In one embodiment, the additive package 30 is water soluble and the cement is a pre-mix type, meaning that it is a wet paste when the container 12 is opened. A preferred material for the package 30 is water-soluble polyvinyl alcohol; however, other water-soluble plastics are contemplated, provided that they are completely water-soluble at room temperature. Once the package 30 falls or is placed into the bonding agent 22 entering the master container 12, the package dissolves and becomes part of the mixture. As shown in fig. 3, it is contemplated that the dynamic mixer 36 is used to completely mix the contents. Referring now to fig. 6, it is contemplated that the package 30 is made of a water insoluble material and is provided by the user in at least one of a narrow rectangular shape called a "stick" package and a bag of an opposing square or circular shape, and the additive 32 is mixed with the base cement 22.

Another feature of the present system 10 is that the additive package 30 is provided to the user in relatively small volume doses, desirably in small batches of cement for small wall repair operations or the like. Preferably, the additive package 30 contains an additive 32 in the range of 5 to 20 grams. More preferably, the package 30 contains in the range of 10 grams of additive.

Further, it is contemplated that the fully formulated bonding agent in powdered form is packaged within one of the packages 30. Such containers 30 are optionally provided in various volumes, including but not limited to 1 pound packages.

Yet another feature of the present system is that multiple relatively small volume packages 30 may also contain the same additive 32. For example, in the case of an accelerator, for a given batch of bonding agent 22, the user adds multiple packages 30 of accelerator to obtain a relatively faster cure of the completed mixed bonding agent 22.

Referring now to fig. 4 and 5, another embodiment of the cement additive system 10 of the present invention is generally designated 40. Components shared with the system 10 are denoted by the same reference numerals. The main difference in the system 40 is that the additive package 30 is secured within a designated additive container 42, which additive container 42 is separate and isolated from the main container 12. The additive package 30 in system 40 has the same features as in system 10.

In the additive container 42, when provided in a water-soluble form, the package 30 is prevented from exposure to moisture, which would cause it to prematurely dissolve and release the additive 32. As with the main container 12, the additive container 42 includes a base 44, an annular wall 46 and an upper lid 48, which are preferably integrally joined, such as by being made of molded plastic. A lid 50 covers the upper lid 48 and encloses an additive chamber 52, the additive chamber 52 enclosing the additive package 30 and maintaining the additive 32 in an inactive state until needed for use.

As shown in fig. 5, once the operator desires to incorporate the additive 32 into the joint compound 22, the additive container 42 is opened and at least one and preferably a plurality of additive packages 30 are deposited into the master container 12, wherein the packages 30 dissolve and the additive 32 is mixed into the master joint compound 22. Preferably, a dynamic mixer 36 is used as needed. When using the water insoluble package of fig. 6, the user tears or cuts the package 30 and manually empties the additive 32 into the base joint compound 22, wherein the additive is mixed as known in the art.

In use, including in system 10 or system 40, a user places the water-soluble additive package 30 into the main container 12 and adds sufficient water to dissolve the package in the water to mix with the packaged powder or pre-mixed cement 22 to achieve the desired cement. It is contemplated that several such packages 30 or containers are provided in a sealed

container

28 or 42, thereby reducing mess and dust generated when mixing conventional powder-type curing cements.

While particular embodiments of the present packages for delivery of additives to powdered compositions have been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.

Claims

1. A bonding agent system (10,40) that addresses the problem of keeping individually packaged additives isolated from a base bonding agent prior to use to adjust bonding agent properties, the bonding agent system comprising:

a main container (12) of a base joint compound (22);

an additive container (28) containing at least one additive package (30) constructed and arranged such that each additive package (30) is protected from exposure to moisture prior to its final mixing with the base joint compound (22); and

the main container (12) having a removable lid (24) and the additive container (28) being located on the lid (24);

characterized in that each of the additive packages (30) stored in the additive container (28) is water-insoluble and is provided by at least one of: a narrow rectangular shape, referred to as a "stick" pack, and a square or circular shaped bag configured to be torn by a user, such that the user manually empties the additive from the additive package (30) into the base joint compound (22) to adjust the properties of the joint compound during mixing; wherein the additives provided in the additive package (30) are selected from the group consisting of dedusting agents, binders, pigments, adhesion promoters, activators, accelerators, retarders, and thickeners.

2. The bonding agent system (10,40) according to claim 1, wherein the base bonding agent (22) is a powder or a premix.

3. The cement system (10,40) according to claim 1, wherein the additive container (28) is located on an underside (26) of the lid (24).

4. The cement system (10,40) according to claim 1, wherein the additive container (28) is provided with frangible walls.

5. The bonding agent system (10,40) according to claim 1, wherein the at least one additive package (30) is a plurality of packages, each of the packages containing one of the same or different additives (32) as the other of the packages in the plurality of packages.

6. The cement system (10,40) according to claim 1, wherein the additive package (30) contains an additive (32) in a range of 5 to 20 grams.

7. The cement system (10,40) according to claim 6, wherein the additive package (30) contains 10 grams of the additive (32).

8. The cement system (10,40) according to claim 1, wherein the additive package (30) contains the complete cement.

9. The cement system (10,40) according to claim 1, wherein:

said at least one additive package (30) is a plurality of packages, each of said packages containing one of the same or different additives (32) as other of said packages in said plurality of packages; and is

The additive package (30) contains an additive (32) in the range of 5 to 20 grams.

10. The cement system (10,40) according to claim 9, wherein the additive package (30) contains 10 grams of the additive (32).