Description of Related Art A wide variety of spray-on cellulose insulation materials and systems for spraying insulation on ceilings, floors, and walls is disclosed in the prior art. The prior art discloses various"stabilized"spray-on or blow-in insulations for cavity walls which include loose fill fibers, moisture, adhesive material or both, to produce a somewhat rigid, stabilized mass with a desired reduced density. Such a mass may exhibit wet strength and may be temporarily self-supporting. In one aspect such a prior art method employs some dry adhesive material that is activated by water. Certain of these prior art methods result in wasting an amount of sprayed-on or blown-in material which exits the area to which they are to be applied. Such material that is not deposited at the desired location, typically in the form of dust and overspray, must be collected and recycled or disposed of. Moving air can affect a surface to which such a mixture is applied, removing fibers from the surface and relocating them in an undesirable location. Such a mixture may settle and pack down in an undesired manner and may be easily damaged by workers and tradespeople working in the location.

Two-component adhesive resins are commonly used with sprayed-on and blown-in fibrous cellulose insulating materials. US-A-4,187, 983 (Boyer, National Cellulose Corporation) discloses systems for applying fibrous cellulose insulation material with an adhesive. US-A-4,360, 440 (Boyer) discloses insulating fiber mixtures that include water, fibers, and an adhesive that is a combination of sodium silicate and an acrylic resin. In particular, it discloses that although sodium silicate and acrylic resins are generally regarded as immiscible, and although even when such mixing was attempted the two ingredients usually would separate from each other. However, if they

were agitated together sufficiently in certain proportions an excellent homogeneous adhesive could be formed which, if sprayed with fibers, gave a product that had increased flexibility, increased surface flame retardance and increased fire resistance.

The flame spread index and fuel contribution factor were dramatically improved. Also the resulting product can be sprayed on a substrate ceiling to a thickness up to 15 cm (6") for a single setting, nearly tripling the average capability of the prior art products.

US-A-5684068 (Boyer, International Cellulose Corp.) is concerned with spray-on insulation systems and discloses a method for forming spray-on cellulosic insulation by providing a first component comprising cellulosic fibres, providing a second component comprising a polyvinyl alcohol-containing adhesive and boric acid or another acidic medium optionally with an additive such as an acrylic polymer, mixing the first and second components and spraying them onto a substrate. US-A-5,853, 802 (Boyer, International Cellulose Corp. ) discloses treating cellulose fibers with boric acid, and applying an adhesive composition to the cellulose fibers, the adhesive composition comprising polyvinyl alcohol cooked without addition of boric acid and optionally an additive such as an acrylic polymer.

Summary of the Invention Certain spray-on insulation materials that include an alcohol-contianing adhesive [e. g., a polyvinyl alcohol] as applied exhibit a whitish discoloration that, in some applications, is undesirable. There has been a need, recognized by the present inventor, for a spray-on insulation material that, when applied, reduces, inhibits, or eliminates undesirable discoloration or whitening.

The invention, in certain embodiments, provides a method for applying fibrous cellulose insulation to a substrate, the method comprising mixing cellulose fibers with an adhesive in aqueous solution and with a discoloration reducing additive thereby producing a mixture, and applying the mixture to a surface of the substrate.

The invention, in other embodiments, provides a method for applying fibrous cellulose insulation to a substrate, the method comprising mixing cellulose fibers with

an adhesive in aqueous solution and with a discoloration reducing additive thereby producing a mixture, applying the mixture to a surface of the substrate, and wherein the mixture occupies a first space as applied and, upon settling, occupies at least 95% of said first space.

The present invention, in further embodiments, discloses a spray-on fibrous cellulose insulation mixture that includes the insulating cellulose fibers; one or two components of a two-component resin adhesive material (with or without added water in the adhesive); and a dispersant [e. g. , a dispersant, detergent polymer, water-soluble polymer for reducing encrustation, polyacrylate polymer, and/or acrylic and polyacrylic acid mateials], e. g. , but not limited to commercially available Rohm & Haas ACUSOL (TM) 445 dispersant polymer material.

The invention, in yet further embodiments, provides a method for applying fibrous cellulose insulation to a substrate, the method comprising mixing cellulose fibers with an adhesive in aqueous solution comprising polyvinyl alcohol and a dispersant, perferably a polymeric anionic dispersant of molecular weight 1500- 10,000, thereby producing a mixture, and applying the mixture to a surface of the substrate.

Description of Preferred Embodiments The cellulosic fibers in any mixture described herein may typically have a largest dimension of 2.5 mm. They may be treated with an acidic medium, for example borates or boric acid. This treatment may be carried out by pounding or grinding the acidic material into the fibrous material, e. g. with a suitable hammer mill or other apparatus. For example the acidic medium may be powdered boric acid may be powdered boric acid which is ground-in to the cellulose fibers with a mill, or it may be aqueous boric acid sprayed onto the cellulose fibers, or in a third variant it may comprise both powdered boric acid ground-in to the fibers and aqueous boric acid sprayed onto the fibers.

The fibers may be combined or mixed with an"alcohol"adhesive e. g. , but not limited to, polyvinyl alcohol adhesives, (e. g. but not limited to those disclosed in U. S.

Pat. Nos. 5,684, 068 and 5,853, 802, and in prior art cited therein) or with an alcohol-containing adhesive. A preferred alcohol-containing adhesive contains a polyvinyl alcohol (PVOH), and in a particular embodiment the adhesive may be a PVOH cooked without the addition an acidic medium or pH adjusting medium.

"Cooked"means heated to a temperature at which a reaction occurs so that the powdered PVOH becomes liquid or gelatinous so that is mixes with water to form a solution. Cooking is done by raising the temperature of water and PVOH, e. g. to about 88-107°C (190-225°F) while agitating the water and PVOH and maintaining the raised temperature for sufficient time to produce the desired solution, e. g. for a minimum of one hour.

The dispersant and/or discoloration reducing agent may be a polymer surfactant or detergent polymer of molecular weight from about 1500-10,000, more preferably about 3000-6000 in which at least about 30% of the repeating units are derived from an anionic monomer which may be completely or partially neutralized with an inorganic or with an organic cation. These polyanionic materials are usually supplied as viscous aqueous solutions, often having 30-50% polyanionic material, which may be un-neutralized. Suitable materials include acrylic acid or methacrylic acid homopolymers or acrylic acid or methacrylic acid copolymers with acidic and/or neutral olefinic monomers and completely or partially neutralized alkali metal, ammonium or amine salts of any of the above. As possible acidic comonomers there may be mentioned maleic acid, maleic anhydride, fumaric acid, itaconic acid and the like. Neutral monomers include methyl and ethyl acrylate and methacrylate and hydroxyethyl acrylate and methacrylate and the like. Preferred polycarboxylates are derived from low molecular weight (MW) about 1500-10,000 polyacrylic acid homopolymer (PAA). the preferred polyacrylate being a homopolymer sold as ACUSOL (TM) 445 by Rohm and Haas Company and having a molecular weight of about 4500. The polyacrylate is normally available in solution, where the solution is 48% polyacrylic acid and the balance water. Thus the material may be described as a dispersant, detergent polymer, water-soluble polymer for reducing encrustation,

polyacrylate polymer, and/or acrylic and polyacrylic acid mateials e. g. , but not limited to commercially available Rohm & Haas ACUSOL (TM) 445 dispersant polymer material.

Embodiments of insulating material produced according to the present invention may further comprise a surfactant and/or a cross-linking agent. Any suitable known surfactants and cross-linking agents may be used.

In certain systems that use spray-on nozzles, mixing occurs at the nozzle. In one systems according to the present invention, fibrous cellulose is provided in one line to a plural-component spray nozzle and an adhesive component (e. g. , but not limited to, an A component, and A and B component, or alcohol-containing adhesive as described herein) with dipsersant material is provided in another line to the nozzle.

In certain embodiments a mixture is produced for spraying onto a floor (either or both surfaces--top and/or bottom) or onto a wall or part of a wall to produce an insulated section thereof. The applied material may or may not, according to the present invention, be enclosed between panels or boards and/or sprayed into a pre-built wall or under-floor cavity; e. g. an outer wall surface and an inner surface of house exterior sheathing may define a wall cavity or a bottom surface of a floor and top surface of a ceiling or of some other board or sheathing may define a cavity beneath the floor into which the material is applied.

Desired resultant densities (density of the material after application and drying) for material according to certain embodiments of the present invention in a cavity wall are: about 1.5 to about 6.5 pounds per cubic foot and for certain embodiments between 1.5 to 2.5 pounds per cubic foot. In certain aspects, desired resultant densities for attic floors are between about 1 to 15 about 4 pounds per cubic foot, and, in certain aspects, between about 1 to about 2 pounds per cubic foot (and in one aspect 2.0 or less).

With any method described herein, for an applied mixture (adhesive+fibers), e. g. on an attic's floor top side, that can settle and pack down, it is preferred according

to the present invention that such settling be no more than 5% and, with the methods and materials described for the preferred embodiments above, that it be no more than 2.5%.

In certain embodiments the mixture has these properties: Using an A component only "X Ratio" : Water to Adhesive 3: 1 to 15: 1 (by volume as applied) (10: 1 preferred) "Y Value" : Adhesive Mix/Fibers 0.05 to 0.30 (gallons of adhesive solution - or mixture-per pound of fibers) "Z Ratio" : Discoloration 5: 1 to 50: 1 affecting additive (gallons of adhesive per gallons of additive) In one preferred mixture using an A component only as the adhesive the ratio of water to adhesive is 10 to 1 and about 0.10 gallons of mixed adhesive are used per pound of cellulose fibers, and discoloration reducing additive [dispersant] is used in the form of Rohm & Haas ACUSOL (TM) 445 material and in the amount of one gallon of this dispersant per ten gallons of adhesive.

In certain aspects when applying such a mixture to a floor, e. g. to the underside of a floor, the ratio of adhesive to water is increased and the ratio of adhesive mix to pounds of fiber is increased.

Such"A component only"mixtures may be applied to a wall e. g. blown onto a wall with a water mist or sprayed onto a wall, into a wall cavity, or into an attic area,

including the top side of the attic floor, the inside of the attic walls, and/or the underside of a roof.

In certain wall or ceiling applications, with an"A component only"mixture, the X ratio is between 2: 1 and 15: 1 (with 4: 1 preferred); and the Y value is between 0.10 and 0.40 (with 0.23 preferred). For certain cavity wall applications, the preferred Y Value is 0. 10.

Using an A and B component X Ratio: Water to Adhesive 3: 1 to 15: 1 Y value: Adhesive Mix/Fibers 0.05 to 0.30 Resin Ratio: A component component 9: 1 to 1: 9 Z Ratio: 5: 1 to 50: 1 In one preferred mixture, the Resin Ratio is 5: 1, the X ratio is 10: 1, and about 0.13 gallons of mixed adhesive and water is used per pound of fibers. In another preferred mixture, the Resin Ratio is 3: 1, the X ratio is 4: 1, and about 0.23 gallons of mixed adhesive and water is used per pound of fibers. The ratio of adhesive to dispersant (the Z ratio) for these preferred embodiments is 10: 1. In certain cavity wall applications, the preferred Y value is 0.13.

In further embodiments of the present invention a mixture according to the present invention is applied in an attic as follows: Resin Ratio : 9: 1 to 1 : 9# (5: 1 preferred) X Ratio: 4: 1 to 50: 1 (10: 1 preferred) Y Value : 0.005 to 0.100 (preferred 0.010)

Z Ratio : 5: 1 and 50 : 1 (10: 1 preferred) In an attic application as above in which an A component material only is used, there is no A to B ratio and the X ratio is between 3: 1 and 50: 1 with the Y value as above and a Z ratio of 5: 1 to 50 : 1 with 10: 1 preferred.

In one particular embodiment, a mixture according to the present invention is as follows: 1 to 20 parts adhesive by volume 5 to 20 parts water by volume 0.1 to 2 parts dispersant by volume In one preferred mixture there is 1 part adhesive to 4 to 15 parts water; and, more preferably, 8 to 15 parts water. Such a mixture (between about 0.05 to 0.30 gallons) is then combined with one pound of fibers and with 0. 10 gallons of dispersant per gallon of adhesive. In one aspect the adhesive is a polyvinyl-alcohol containing adhesive.

In certain embodiments a mixture according to the present invention as follows is applied to a substrate: Material Ratio Water to Adhesive 3: 1 to 15: 1 (Gallons water to gallons adhesive) Adhesive to Cellulose Fibers 0.05 to 0.30 [gallons adhesive to pounds of fiber;"adhesive"here includes additive]

Adhesive to Additive 5: 1 to 50 : 1 (gallons adhesive to gallons additive) In one particular mixture according to the present invention, to one part (by volume) of an A component such as a PVOH adhesive is added 3 to 15 parts (by volume) of water. To the resulting mixture is added between 0.05 gallons to 0.30 gallons (of adhesive + water) per pound of fibers, and a Z ratio of 10: 1.

In another particular method and system according to the present invention about 0.03 to about 0.75 gallons of a resin component A or of resin components A plus B are used per pound of fibers.

In one embodiment 1 gallon of adhesive+dispersant is used to spray-on 220 pounds of fibers at 0.05 gallons/pound when reduced at a ratio of 10: 1 with water.

The present invention, therefore, in at least certain but not necessarily all preferred embodiments provides a method for applying fibrous cellulose insulation to a wall, the method including mixing cellulose fibers with an adhesive in aqueous solution thereby producing a mixture, and applying the mixture to a surface of a wall. Such a method may include one or some (in any possible combination) of the following: 'The adhesive is an alcohol-containing adhesive.

'The alcohol-containing adhesive is a PVOH adhesive, wherein the PVOH adhesive may be cooked with or without the addition of an acidic medium; The adhesive is present as between about 0.05 to about 0.30 gallons of adhesive-in-water solution to about a pound of fibers, preferably between about 0.08 to about 0.18 gallons of adhesive-in-water solution to about a pound of fibers.

The ratio by volume of water to adhesive in the aqueous solution containing adhesive is between 3: 1 to 15: 1.

'The adhesive is an A component only adhesive.

The ratio of water to adhesive in the aqueous solution is 10 to 1 and 0.10 gallons of the solution is used per pound of cellulose fibers.

The adhesive is a B component only adhesive.

'The adhesive is an A+B component adhesive wherein the ratio of A component to B component is between 9: 1 to 1: 9.

The ratio of aqueous solution with adhesive (gallons) to fibers (pounds) is 0.05 to 0.30, the ratio of A component to B component is 5: 1, the ratio of water to adhesive in the aqueous solution is 10: 1; and about 0.13 gallons of mixed adhesive and water is used per pound of cellulose fibers.

Prior to the mixing step, treating the cellulose fibers with an acidic material, wherein: o the treating may be done by pounding acidic material into the cellulose fibers; o the acidic material may be boric acid; o the resultant density of the applied mixture may be between 1.5 to 6.5 pounds per cubic foot; o the resultant density of the applied mixture may be between 1.5 to 2.5 pounds per cubic foot, preferably 2.0 or less.

The mixture is applied by spraying it onto the wall.

Spraying the mixture with a spray nozzle onto the wall, the method including introducing the cellulose fibers under pressure through a first hose into the spray nozzle, introducing the adhesive in aqueous solution under pressure through a second hose into the spray nozzle, and spraying from the spray nozzle the mixture onto the wall.

Applying the mixture onto the wall to a thickness of at least 4 inches and in some embodiments to a thickness of at least 6 inches.

The mixture occupying a first space as applied and, upon setting, occupying at least 95% or 99% of said first space.

The mixture occupying a first space as applied and, upon drying, occupying at least 99.5% of said first space.

A barrier is spaced-apart from and adjacent the wall forming a cavity between a

surface of the barrier and a surface of the wall, the mixture deposited within the cavity.

The mixture occupies a first space as applied and, upon settling and drying, occupies at least 95%, 99% or 99.5% of said first space and/or . Discoloration reducing additive is added to a polyvinyl alcohol adhesive [e. g. commercially available SK-2000 (TM) material from International Cellulose Corporation] prior to combining this combination with cellulose insulation material.

[METRIC CONVERSIONS: 1 pound is 0.45 kilogram; 1 gallon is 3.8 litres; 1 cubic foot is 28 litres]