CA1110804A - Effervescent adhesive-forming product - Google Patents

Abstract

ABSTRACT

This invention relates to an effervescent composition useful for making a holding adhesive, especially a wall covering adhesive. The composition comprises a water-soluble polymeric adhesive base and a compatible effervescent source.

Description

Case 1555B
l~lQ8~)4 January 12, 1978 1 :
BLR:pe -1 E:FFERVI~SCENT ADlll~SIVi,-FORNIllG PRODUCT

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Il Bsckground of the Invention ,¦ The present lnvention relates to an adhesive-forming I product, ~ore particularly, lt relates ~o an effervescent I article of manufacture which, when mixed with water, is suitable 1 for u~e as a holding adhesive, especially as a wall covering adhesive. The wall coverings for which this invention are l especlally suited are wall papers, including the vinyl-coated 3 and fsbric-backed Yarieties. Other sheet materials for which the i~ adhesive-forming composition are u~eful include paper, card-I board, fabric and the llke.
Adhesive products for adhering these types of wallcoverings have classically been formulated from such natural 60urces as stsrch, dextrin, gum arabic, gum tragacanth and certain modified casein or other animal protein bases. Most ' are dispeTsed as powders in water and develop, after application,¦
, thelr strength by drying. In recent years such adhesive products have been f~rmulated with synthetic polymers to provide enhanced i water resi6tance.
! Adhesive products suitable for use as wall covering adhesive~ are designated as holding adhesi~es, i.e., adhesives I that are intended primarily for merely attaching one adherent ! to another and holding it in place without requiring any signi-ficant rèsistance to external stressing~ The working properties .
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Case 1555B
January 13, 1978 1~108~4 BLR:pe -2 .1 1 of such a holding adhesive product include characteristics that influence application, such as mixing, spreading, pressing, curing, speed of curing or rate of strength development and convenience of cleaning up afterwards. Heretofore, commonly avallsble wall covering adhesive products have been messy and I inconvenient to formulate and clean up, The packages of dry powder wall covering adhesive products commonly sold afford bstches of a wall cover~ng adhesive sufficient to paste an average size room. Scaling down to a smaller batch of the l adhesive involveg measuring the contents of the package, deciding how much ls neeted, snd then mixing the required smount of dry I powter with the proper amount of solvent. Thus, a worker i requlring only a ~mall amount of the adhesive usually wastes a , substantial amount of the adhesive by premixing the entire pack-age in order to avoid this bothersome procedure. Available dry powder adhesive products (which are non-effervescent in nature) ¦ al80 suffer from the disadvantage ~hat they are inconvenient to I mlx ln either small or large batches due to the lumping, caking ;1 and 6tickine6s that are characteristic of the resultant mixture -I of dry powder and water. Preparing a lump-free paste mixture 1 often involves portionwise addition of the dry powder to the ! volume of water couplet with vigorous and continuous stirrin8.
. SummarY of the Invention Thi6 invention provides convenient, easy-to-mix and

2~ easy-to-measure product which, when dispersed ln water, is useful as a hold~ng adhPsive especially as a wall covering adhesive.
It provides an article of manufacture which may be conveniently mixed with water and in either small or large batches. This composition, when contacted with water, w~ll readily disperse '!

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Case 1555B
January 13, 1978 BLR ne --3 8~4 ~ I
and thus minlmize the need for messy and incon~enient mixing.

li etailet Description of the Invention 1, It has surpri~ingly been found that one can selectively I formulate an adhesive base and a compatible effervescent source 1l to provide a stable product from which it is easy and quick to ¦ prepare a homogenous holding adhesive solution. One might have ~nticipated that an adhesive base would, upon dropping in water, ¦
form a gelatinous mass from which it would be difficult and time ¦
consuming to form a homogenous solution. However, I have found 1¦ that the combination of a selected adhesive base with an effer- ¦
vescent source prov~des the mlxture force necessary to afford a homogenoua solution. The effervescent composition may be packaged as a pre-measured powdered mixture or alternatlvely, il compressed into a tablet form. The effervescent product of the I present invention is an article of manuf~cture which comprises by weight:
20-50% of a water-soluble polymeric adhesive base;
45-80% of a compatible effervescent source consisting essentially of an acid component and a carbonating component I whereby the acid component and carbonating component are present ¦ in amounts sufficient to afford a watar solution of approximately ¦ pH 3.5-9.5.
il A preferred effervescent product ln powdered form of ¦ this in~ention comprises by weight:
¦ 30-50Z of a wster-soluble polymeric adhesive base; and ~ 50-70% of a compatible effervescent source consisting i essentially of an acid component ar.d a carbonating component I¦ whereby the acid component and carbonating component are present 1 in amounts s~fficient to afford a water solutton of approximately I p~ 3.5-9.5.
Another preferred embodiment of the present invention ls a tableted form which by weight compr~ses:
, Case 1555B
January 13, 1978 8~4 BLR:pe -4 25-40~ of a water-soluble cellulosic adhesive base;
I 20-30~ of a compatible acid component;
30-40% of a compatlble carbonating component; and l 1-2X of an anhydrous solvent which ls water mlscible and ln whlch the adheslve base ls substantlally insoluble and ~ non-swelllng. ~-I In a preferred effervescent product of thls lnvention the adhesive base is hydroxyethyl cellulose, and the efferves-I cent source conslsts essentially of citric acid and sodium car-¦ bonate.
The adhesive base of this composition ls the component whlch 18 prlmarily responslble for the adheslve forces whlch holt the one adherent to the other. Sultable water-soluble j polymeric adhesives are those such as the starches, e.~., corn, 'I tapioca and sago, dextrins and the water-soluble celluloses, such as hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose and ethyl-hydroxyethyl cellulose. A preferred water-;l soluble, celluloslc adhesive base for use in this invention is hydroxyethyl cellulose having a degree of substitution from 1.5 to 3Ø A suitable hydroxyethyl cellulose source are those ;, commercial preparatlons sold under ~he tradename Natrosol ~by ¦ Hercules Ghemical Co.), and especially Natrosol 250.
The compatible effervescent source embodied in the ¦ present invention refers to compositions capable of liberating 2-5 ~¦ carbon d~oxide in the form of bubbles when plsced in an aqueous - 1¦ media, thereby producing the effervescence, and which do not chemically react with the other components of the composition.
, Effervescent compositions capable of generating carbon dioxide 'I are thus composed of a solid source of carbon dioxide, such as 11 a earbonate and/or blcarbonate, in comblnation wlth an organic or i~organic acid which, upon contact with water, react to liber-Case 1555B
~4 January 13, 1978 BLR:pe -5 ate carbon dioxide in the form of bubbles. The acid component may constitute a single acidlc material or a combination of !l solid acld substances. Typcsl scid components include citric l acid, tartarlc acld, malic acid, succinic acid, fumaric acid , and combination~ thereof. The carbonating component usually takes the form of a carbonate or a bicarbonate~ or any mixture thereof. More preferably, the carbonating component will be a , non-toxlc salt of carbonic acid in any of its forms, and most '' preferably one of the alkali metal carbonates or bicarbonates, 1 e.~., sotium carbonate or sodium blcarbonate. The acld component, and the carbonatlng component are present in the composltion in fiuch amounts so as to produce a solution having a p~ of 3.5-9.5 when the composition i8 ~lxed with water. By ad~usting the Il amounts of the acid ant carbonating components it is posslble to ;I control the speed of dissolution of the product, i.e~, by adding j more carbonating component and makin~ the pH more basic; or the , i "stlcklness" of the adhesive, i.e., by adding more acid component and making the pH more acldlc. Thus, to afford a product for I heavler materials, a product having a greater percentage of acid ~ component is added to afford better adhesion. For faster dls-solutlon where the adhesive i8 for light materials such as paper,, ¦ the product wlll contain more carbonating component.
'I Optionally, an anhydrous solvent may be employed to l¦ facllitate tabletlng when the product is in tableted form. When ll used, it may be any of a numbe~ of commonly used solvents which - ¦ are water miscible and in whlch the water-soluble adhesive base 1 is substantially lnsoluble and which does not cause the polymeric ¦ adhesive base to swell. Preferred solvents are the lower alkanols, I ~uc~ as anhydrous ethyl alcohol and anhydrous isopropyl alcohol.
1 Anhydrous lsopropyl alcohol is most preferred for use in this ' inventlon. Other solvents which also may be used are those in which the water-soluble adhes~ve base is not soluble and which I Case 1555B
~ 8~4 BLR.pe -6 ., I¦ does not cau~e swelling, such as the higher alkanols, ketones, dlethylene glycol monoethyl ether, diethylene glycol momoethyl ether~ ethylene glycol monobutyl ether acetate and hexylene l glycol.
1I To further facllitate tableting, a conventlonal I tableting binder may optionally be employed. It should be I soluble in the foregoing anhydrous solvent and inert ~o the I other components of the mixture, Suitable binders include gum ~ acacia, gelatin, gum tragacanth, guar gum, sodium carboxymethyl ! cellulose, ethyl celluloge, hydroxypropylmethyl cellulose, starch glucose or a carboxypolymethylene polymer (carbomer). The tableting binder i8 preferably water soluble. The carboxypoly-¦ methylene polymers, or carbomers (CTFA Cosmetic Ingredient ~¦ Dlctlonary 1973), are preferred tableting binder agents for use 1 in thls invention. Those resins consist essentially of a I collo~dally water-soluble polymer of acrylic acid crosslinked 'I with from 0.72 to 2X of a crosslinking agent selected from the class co~si6tlng of polyalkyl sucrQse and polyallyl penta- 'I
j erythritol. Suitable carboxypolymethylene polumers, or carbomers, ¦ are those marketed under the tradename of Carbopol resins by the B. F. Goodrich Company. A preferred polymer is the carbomer 934,', ! wh~ch ls a water-soluble polymer of acrylic acid crosslinked ~I with about 1% of a polyallyl ether of sucrose having an average i¦ of about 5.8 allyl groups for each molecule of sucrose and having~
~¦ a molecular weight of about 3,000,000.
I! Thus, in the embodiment wherein a tableting binder i~
j¦ used, the adhesive base must be insoluble in the chosen anhydrous solvent while the tabletlng binder must be soluble in the ~ anhydrous solvent and the latter must be water-miscible.
The products of the lnvention are conveniently , manufactured by well-known methods and are packaged in sizes so as to provide a convenient quantity of wall-covering adhesive when the sontents of the package are dissolved in wster. This I Case 1555B
' January 13, 1978 ~ 8~4 BLR: pe -7 quantity i6 preferentially from about 2 oz. - 8 oz. which affords about 1 qt. - l gal. of mixed adheslve. For the purpose of thls I speclflcation, the term "tablets" covers pellets, briquettes and l slmllarly formed shapes. The dry base ls blended with the ¦ effervescent source until uniformly mlxed and then moistened with l the solution of the tableting binder ln the anhydrous binder I sol~ent, The mlXture ls then compressed into the desired shape I on a tableting machine and packaged.
The composltlons of the present invention may option-0 j 811y lncorpor~te conventional water-s41uble preservatives and mlldewcltes. More particularly, when a cellulose derivative ls used as the adhesive base, a preservative may be added to insure stability and enhance shelf-life for the product. The use of ~¦ a preservsitive additionally serves to lnhlbit miltew and mold ,1 ~I growth on the spplied a~hesive. Suitable preservatives include, ,I but are not limited to, chlorinated phenols, hydroxyquinoline, parshytroxybenzoates (methyl, propyl, heptyl, etc.), phenyl-mecuric salts (acetate, nitrate, etc;), sodium benzoate and sorbic acid. Such preservatives and/or mildewcides are usually I present in an amount of about 0.01-5X by weight, depending on the particular agentfi utilized.
'I The finished tablets, pellets or briquettes of this I¦ lnventlon a~ preferably packaged in hermatically sealed, mois-~¦ ture~proof containers, e.~., cellophane (cellulose acetate~; I
il polyethylene polyvinyl resin or foll wrappers, or covered with a ¦
,¦ ~uitable plsstic film to protect them from atmospheric moisture Il prior to consumer use.
When the composition i~ left in powdered form without ~I table~ing, it is preferably similarly packaged in pre-measured, I hermatically-sealed, moisture-proof pouches, ~ Suitable packages are those such as described in ,' U.S. Pstent 3,057,467.

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Ca~ie 1555B
January 13, 1978 BLR~pe -8 Speciflc Embodiments of the In~ention , The following examples describe in detail compositions lllustrative of the present inventlon. It will be apparent to l those 6killed in the art that many modifications, both of mater- ¦
' ial6 and methods, may be practiced without departing from the i purpose and lntent of thls dlsclosure.
Example 1 A powdered composltion suitable for use as a wall l1 covering adheslve when mixed with water ls prepared from the ,¦ followlng:
¦ Component Percent bY Wei~ht Hydroxyethyl cellulose 40 (Natrosol HBR) j Sodium ~arbonate 36 ~I Cltrlc acid 24 1 Blend together the above lngredients in powder mlxing equipment, e.~., a P.K. ~lender or a Ribbon mixer, then package I ln hermatically-sealed, moisture-proof pouches.

! Example 2 ' A tablet 6uitable for use 8S a wall covering adhesive when mixed with water i8 prepared from the following:
~' Component Percent bv Wei~ht Hydroxyethyl cellulo6e 33.9 l (Natrosol 2~0) ! Sodium carbonate 37.3 I C~tric acid 27,0 ' 2~ i Anhydrous isopropyl 1.8 ! alcohol Blend together in a P~K. Blender equipped with a I liquid feeder the hydroxyethyl cellulose~ sodium carbonate and ,' 'I citric acid until uniformly mixed. Then feed the anhydrous I isopropyl alcohol into the mixer. When the powders are uniformly 'I
moistened, feed the mixture into a tablet machine hopper for compacting into 50-60 gra~ tablets. The finished tablets are C.lse 1555B
i January 13, 1978 i~Q4 BL~:pe -9 , packaged in molsture-proof cellophane packages for shipping, i Example 3 A tablet suitable for use as a wall covering adhesive ~ when mlxed wlth water is prepared from the following:
¦ Component Percent bY Weight l Hydroxyethyl cellulose 28.57 I (Natrosol 250) Sodium carbonate 34.28 Citric acid 22,86 Il Anhydrous lsopropyl 14,15 ~J alcohol ¦~ Carbomer 934 0,14 i! Blend together the hydroxyethyl cellulose, sodium ¦¦ carbonate and citric acld in powder mixing e~uipment such as a Il P,R, Blender equipped with a liquid feeder, Blent until the 15 l¦ chem~al powders are uniformly mixed, Dissolve the carbomer 934 i I in anhydrous isopropyl alcohol and feed the solution into the mi~ar, When the powders are uniformly moistened ~ith alcohol 1 ~olutlon, feed the mixture into a tablet machine hopper for 'I compacting into 50-60 gram tablets ant packaging. The finished 20 l¦ tablets are packaged in moisture-proof cellophane pac~ages for shlpping, A 60 gram tablet prepared as above i8 dropped into one Ij qua~t of room temperature tap water. The mixture is allowed to ,1 6tand until dissolu~ion is complete, stirred thoroughly once, I
2S I and i8 then rendy for u~e as a wallpaper adhesive. I
~ When used to apply regular wallpaper, thls adhesive i composition exhibit "good" adhesion strength after one day and "good" adhesion strength after 10 days, "Good" adhesion strength' l tenotes that the adhesion i8 very strong and that the test l¦ sample cannot be removed intact upon peellng from the sub~trate.
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Case 1555B
~! January 13, 1978 ~ Q8~4 BLR:pe -10 ~ .
Example 4 A tablet i8 prepared as in Example 2 using the I following: ' I Component Percent bv WeiRht ¦ Hydroxyethyl celluloge 28.57 ! ~Natro801 2503 ¦ .
Sodium carbonte 14.28 I Citric acid 42.87 l Anhydrous isopropyl 14.14 alcohol Carbomer 934 0.14 A 60 gram tablet of this compositlon is dis601ved as ~ ln ~xample 1 and used to apply te~t samples of vlnyl-coated wallpaper to a latex-covered dry wall. "Good" adhesion strength wa~ exhlbited by this composition when the test samples were 1 ~ and 10 day old. Nhen used to apply fabric-backed vinyl-coated i wallpaper, the composltion exhibited "fair" adhesion strength ,iafter 1 to 10 dayg, "Fair" adhesion strength indicates that 'Ithe adhe~ion i8 adequate, but that the test sample can be re,moved I
intact upon peeling from the substrate. '.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-An article of manufacture adapted to prepare a holding adhesive solution comprising a hermatically-sealed, moisture-proof package containing a premeasured amount of a composition comprising:
20-50% of a water-soluble polymeric adhesive base; and 45-80% of a compatible effervescent source consisting essentially of an acid component and a carbonating component whereby the acid component and the carbonating component are present in amounts sufficient to afford a water solution of approximately pH 3.5-9.5.

An article of manufacture according to claim 1 in powdered form which by weight comprises:
30-50% of a water-soluble polymeric adhesive base; and 50-70% of a compatible effervescent source consisting essentially of an acid component and a carbonating component whereby the acid component and the carbonating component are present in amounts sufficient to afford a water solution of approximately pH 3.5-9.5.

An article of manufacture according to claim 1 in tablet form which by weight comprises:
25-40% of a water-soluble cellulosic adhesive base;
20-30% of an acid component;
30-40% of a carbonating component; and

1-2% of an anhydrous solvent which is water-miscible and in which the adhesive base is substantially insoluble and non-swelling.

An article of manufacture according to claim 1 wherein the adhesive base is hydroxyethyl cellulose.

An article of manufacture according to claim 1 wherein the acid component and carbonating component are citric acid and sodium carbonate, respectively.

A tablet according to claim 3 wherein the anhydrous solvent is anhydrous isopropyl alcohol.

An article of manufacture according to claim 1 wherein a preservative and/or mildewcide is added.

An article of manufacture according to claim 1 wherein the premeasured amount is 2 to 8 oz.

A method of adhering wallpaper or the like to a surface which comprises adding a composition of the formula of claim 5 to a suitable quantity of water and applying the resultant adhes-ive to the wallpaper or the like.