WO1987006946A1

WO1987006946A1 - Polyvinyl acetate compositions and processes for making same

Info

Publication number: WO1987006946A1
Application number: PCT/US1986/000988
Authority: WO
Inventors: Thomas C. Wright; Grover L. Johnson
Original assignee: Orin Chemical Company
Priority date: 1986-05-05
Filing date: 1986-05-05
Publication date: 1987-11-19

Abstract

A process of making polyvinyl acetate products includes using an aqueous emulsion of polyvinyl acetate, introducing a salt to the aqueous emulsion to form curds, and eliminating water and cross-linking the curds. The polyvinyl acetate compositions result from such process.

Description

POLYVINYL ACETATE COMPOSITIONS AND PROCESSES FOR MAKING SAME

Cross-References to Related Applications

This patent application is a continuation-in-part of U.S. patent application Serial No. 727,497 filed April 26, 1985.

Technical Field The present invention relates in general to polyvinyl acetate compositions and processes for making same. It more particularly relates to such compositons and processes involving aqueous emulsions of polyvinyl acetate.

Background Art

Polystyrene and polyurethane are the present front runners for preparing foamed products. However, these have many inherent disadvantages, i.e. high flammability, very little structural strength for self-support and for supporting fastening materials such as nails and screws. Polyvinyl acetate polymer foamed products are known.

However, these products are not readily found in the market place. The compositions of the prior art as disclosed in U.S. Patent 2,930,770 do not satisfy the needs of the market place.

Our present invention provides a multipart composition which permits the effective use of polyvinyl polymers for foamed products. The polyvinyl polymers used in the present invention are always water-borne. The polyvinyl polymers of the present invention are those polymers and copolymers of polyvinyl acetate, acrylate, maleate and phthalate and also polyvinyl chloride and polyvinyl acetate-ethylene copolymers.

The preferred polymers used in the present invention are water emulsions of polyvinyl acetate and polyvinyl acetate-ethylene. These are usually used separately but may be mixed if desired. These chemical polymers are readily available and the polymers we used to illustrate our invention were Airflex 400, Airflex 300, Vinac 240 and Airflex 400H, which were purchased from Air Products and Chemicals, Inc. of Allentown, PA. Airflex 400 and Airflex 40OH are a water-based vinyl acetate-ethylene copolymer emulsion, which is 55% solids (Cenco Moisture Balance) . The viscosity is 1400-1600 cps at 60 rpm (Brookfield Viscoraeter, Model LVF at 60 rpm and 77°F.). The viscosity is 1900-2800 cps at 20 rpm (Brookfield Viscoraeter, Model RVF at 20 rpm and 77°F.).

The pH is 4.0-5.0. The residual monomer is .05% maximum. The copolymer type is vinyl acetate-ethylene. The protective colloid is partially acetylated polyvinyl alcohol. The density is 8.9 lbs. per gal. Airflex 300 is similar to Airflex 400, except that the viscosity at 60 rpm is 1700 cps, and at 20 rpm is 2400 cps, and except that the density is 9.0 lbs. per gal. Vinac 240 is similar to Airflex 400, except that the viscosity is 2700-3400 cps at 20-60 rpm, the pH is 4.5- 6.0. Also, the polymer type is homopolymer, and the density is 8.9-9.2 lbs. per gal. Also utilized were polyvinyl acetate water borne emulsions; namely, homopolymer adhesive base (standard) , experimental 6-97 (homopolymer) , experimental 6-124 (copolymer) and experimental 6-239 (copolymer) . They were all purchased from Borden Chemical of St. Louis, MO. The homopolymer adhesive base is a commercially available product, and the others are available for experimental purposes.

The commercially available adhesive base is 45% solids, and has a viscosity of 3500 cps at 60 rpm at 25°C. The pH is 4.0-5.0. It is a homopolymer and has a density of 9.0.

The 6-97 homopolymer is 54% solids and has a viscosity of 3200 cps at 60 rpm at 25°C. The pH is 4.0- 5.0. The density is 9.0. The 6-124 copolymer (blend) is 50% solids, and has a viscosity of 3500 cps at 60 rpm at 25°C. The pH is 4.0- 5.0 and has a density of 9.0.

The 6-239 copolymer (blend) is 58% solids, and has a density of 9.1. The viscosity is 4000 cps and 60 rpm at 25°C and the pH is 4.0-5.0.

In the four Borden Chemical polymers, the protective colloids is polyvinylalcohol. As a blowing agent, we utilize natural and generally non-toxic blowing agents to provide a safe environment for foaming our products. The blowing agent we utilize is carbon dioxide. However, we obtain the carbon dioxide by reacting carbonates and bicarbonates with an appropriate acid. Further, as required by our invention, we use an alkali cross-linking agent. The preferred alkali compounds are Na, K, Li, Rb and Cs, although Mg, Ca, Sr, Ba and Zn can also be used. To effectively obtain both the alkali cross-linking agent and the blowing agent, we use the alkali carbonates and bicarbonates. The most common and readily available are ammonium bicarbonate, potassium bicarbonate, sodium bicarbonate, magnesium carbonate, calcium carbonate and zinc carbonate. Our preferred foaming agent is sodium bicarbonate.

Our invention requires our foam composition to also include an acid to release the carbon dioxide. However, in some cases the use of sodium bicarbonate alone is sufficient to release both the carbon dioxide blowing agent and to provide the alkali action as a cross-linking agent. The use of a cross-linking agent allows the foam product produced by our invention to have greater structural integrity than the foam products of the prior art. Our preferred acids are selected from citric acid, acetic acid, tartaric acid, hydrochloric acid and oleic acid. Of course mixtures of the acids and acid salts may be used. Our preferred salts are alkali bitartarates, monobasic calcium phosphate and monobasic sodium phosphate. Our preferred acid and acid salt are citric acid and potassium bitartate, these both being readily available and, again, being non-toxic and thus environmentally safe for both the workers and the environment in the production of our foam products.

In addition to the above required compounds, other compounds may be utilized depending upon the end product to be produced. Those compounds which may be used may be suitable thickners, plastisizers, protective colloids, adhesives and various dyes. We have utilized and shown various additives such as carboxymethyl cellose, casein, polyvinyl alcohol, polyethylene glycol, starch, wheat gluten, dibutylphthalate, boric acid, gypsum, limestone, vermiculite, wood chips, popcorn chips and granules of popcorn.

The products produced by our invention show excellent flame resistance and stability. Wallboard, produced with our composition had kraft paper on one side thereof. The wallboard may be used as a substitute for the present plaster board used in present wall construction. The wallboard produced by our intention allows screws to be screwed directly into the wallboard without the necessity of an anchor. Also, our wallboard has the same integrity as wood. That is, it will hold a nail in the same fashion that wood holds a nail. This, of course, is superior to the plaster board which is presently used in most construction. Further, our wallboard not only acts as a structural material, but also provides insulation and sound-proofing, which cannot be provided by plaster board.

Also, our composition can be used as a material, ₅ water based paint or coating, and an adhesive. The packing material is light weight and flame resistant, and thus has an advantage over known polystyrene packing materials.

Our paint or coating provides flame resistance and -, _Q insulation.

This is accomplished with polyvinyl acetate emulsion to which an appropriate alkali and foaming agent is added simultaneously. The composition expands as a result of the production of gas bubbles produced by the foaming 15 agent. Curding results, with the curds, being disbursed throughout the composition. The curds are clusters of polyvinyl acetate molecules, which are molecular agglomerations.

Each individual curd expands internally, as the curd 20 polymerizes and cross links together. Simultaneously with the formation of the curds, to form an expanded lattice thereof. Thus, the curds expand internally as well as externally at the same time. The resulting

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polymerized structure is a very light, strong product with good structural integrity.

The simultaneous conditioning the polyvinyl acetate emulsion, and then puffing by foaming or agitation, the resulting composition, the polyvinyl acetate emulsion is conditioned and foamed together concurrently to achieve puffing within the curds, as well as between them. Thus, we expand substantially simultaneously with the curding to produce a final puffed-up product, which contains cross-linked, spaced-apart curds. The a final product is of a low density, and yet structurally strong and tough.

A homogenous polyvinyl acetate/polyvinyl alcohol emulsion at a suitable concentration is treated with an agent (e.g., a salt or alkali) that modifies and increases the viscosity of the emulsion by production of macroscopicagglomerates ("curds") through a process of (l) salting out or (2) isoelectric precipitation, both of which may cause aggregation and affect the size of such aggregates. Simultaneously or subsequently, gas may be entrapped in the viscous emulsion matrix by (1) a chemical mechanism that releases carbon dioxide gas uniformly into the matrix, or (2) physical entrapment of air during a mixing or frothing process. Incorporation of gas produces a foam that further increases the viscosity. These steps determine the physical nature of the product, e.g., density, volume, microporosity, and ultimately flexibility. Chemical stability is conferred by curing, i.e., permanently setting this physical foam by chemical bonding. This may be accomplished by removal of solvent water by evaporation and/or heat. The density, flexibility, and probably many of the product's engineering properties are determined by the size of the polyvinyl agglomerates ("curds") relative to the size of the voids in the product due to gas bubbles.

Commercial "polyvinyl acetate" emulsions are concentrated dispersions of water-insoluble polyvinyl acetate stabilzed as microdroplets in a water base by the addition of polyvinyl alcohol. Such emulsions are fluid but produce tough, flexible films on drying. We surmise that by adding salts (which dissociate into positive and negative ions upon solution in water) we cause aggregation of the polyvinyl acetate microdroplets into larger agglomerates by decreasing the ability of water to repel the small microspheres. The larger agglomerates have the appearance of the "curds" that form when milk—normally a stable miσellar suspension of microscopic particles of protein, fat, and calcium phosphate—is "soured", or acidified. Change in the acid/base balance of the emulsion produces or affects the properties of such curds. Commercial polyvinyl acetate emulsions are commonly stabilized by maintaining the pH of the product near 4.0 (slightly acidic) . Neutralization of such emulsions by the addition of alkali or other substances capable of providing base equivalents (hydroxide ions) apparently alters the stability of the microspheres and force the aggregation to occur. Mechanical rigidity/viscosity. Curding usually increases the viscosity of polyvinyl acetate emulsions by restricting shear-induced flow in such suspensions, for much the same reason that soured milk is more viscous compared to fresh fluid milk. Entrainment of gas bubbles in a curded material increases the viscosity of the emulsion due to restriction of movement of gas bubbles and surface tension in the foam. Gas is or appears to be entrapped by incorporation of air during mechanical mixing of the emulsion ("whipping") or by the controlled release of carbon dioxide gas homogeneously throughout the product by the chemical breakdown of a carbon dioxide precursor such as bicarbonate ion mixed into the emulsion. Gas bubbles occur within or between curds and serve to reduce the density of the polyvinyl material in the finished product.

Curing. A chemical crosslinking of polyvinyl chains serve to stabilize the physical form of the foamed product and to preserve its lowered density. Cross-linking occurs

between linear chains in an end-to-end fashion or appear to bridge adjacent chains to form an entangled meshlike network of chemical molecules, much as cloth is woven from finer threads. Cross-linking and chemical bonding mechanisms in polyvinyl materials occur spontaneously upon physical proximity. Simple removal of water is frequently all that is required to bring polyvinyl surfaces close enough together to allow chemical crosslinking to occur. Removal of water is effected by evaporation and/or heating, but application of heat does not appear to be essential part of the "curing" process.

Molecular aggregation is produced by increasing the ionic concentration surrounding certain macromoleσules, including polyvinyl acetate and polyvinyl alcohol

(Vanderhoff, 1969) . This effect is thought to occur by a process analogous to dehydration whereby the ions contributed by addition of a neutral salt interact with and involve so many water molecules that they cannot effectively hydrate the surfaces of the macromolecules.

Loss.of water of hydration forces interactions between the hydrocarbon chains, with the result that large aggregates are formed by hydrophobic interactions between polyvinyl chains.

Carbon dioxide can be "blown" homogenously into polyvinyl products by the dissociation of a precursor such as bicarbonate ion, which could be contributed as a sodium potassium, ammonium, or other "alkali" salt. Because of the chemical equlibrium between carbon dioxide gas and bicarbonate ion, significant amounts of gas would not be generated without producing slightly acidic conditions (pH below 6) . In the preparation of many of the foamed products evaluated in this study, significant foaming appeared to occur, even though the final pH of the product

remained at or near 7 (neutrality) ; this appears to be due to the dissociation of some bicarbonate ion on contact with acid added as an ingredient of certain formulations (phosphoric, citric, hydrogen tartrate) , even though the amount of bicarbonate added to the formulation was apparently in excess of that required to neutralize the added acid.

Borate ion is known to undergo a relatively weak but specific interaction with 1, 3-glycol residues, leading to the foramtion of boronic acids. Because of polyfunctionality of the boronic acid, oxygen atoms of the borate group may interact with other glycol residue(s) . When the boronic acids are formed with glycol groups on

the same polyvinyl chain, intramolecular bonding occurs. When the boronic acids are formed between glycol groups on different polyvinyl chains, intermolecular bonding, or crosslinking, occurs. Because of the regularity of occurence of 1,3-glycol repeating units in polyvinyl compounds, such molecules are extremely sensitive to the presence of borate ion. Because the reaction is thought to inolve ionized (i.e., charged) borate, such crosslinking reactions occur more readily in alkaline conditions. Sodium borate maintained in an alkaline medium would therefore be expected to more effective than boric acid maintained in an acidic medium. Effects of boration depend on molecular size, borate concentration, and pH. Effects range from minor increase in viscosity, attributable to increase in effective size of polyvinyl polymers, to precipitation, caused by aggregation of polymers into large units.

Cleavage of the acetates ester groups on the . polyvinyl acetate chains generates hydroxyl groups. When water participates in this cleavage, the process is known as hydrolysis. Hydrolysis occurs continually, although perhaps imperceptibly, at a rate that is accelerated by alkaline conditions (i.e., high pH) and elevated temperatures. "Polyvinyl acetate" emulsions are therefore really mixtures of polyvinyl acetate and consist of polyvinyl alcohol, and hydroxyl groups interspersed randomly among acetate ester groups. An increase in the content of hydroxyl groups generally increases the water solubility of such an emulsion and makes it more likely that such a polymer will be sensitive to the effects of agents like borate ion. Under slightly acidic to weakly alkaline conditions (pH 4-9) encountered in this evaluation, extensive hydrolysis of acetate groups is unlikely to occur. Commercial "polyvinyl acetate" emulsions, however, are specifically "tailored" to have certain properties based on their relative contents of polyvinyl acetate and polyvinyl alcohol, so that polyvinyl alcohol is already an important constituent of such products. Partially hydrolyzed polyvinyl acetates may be regarded as copolymers of vinyl acetate and vinyl alcohol. Commercial samples are usually obtained by base-catalyzed alcoholysis of polyvinyl acetate (Moore and O'Dowd, 1965; Odian, 1981) .

The crosslinking action of borate on polyvinyl polymers is that of a weaker ionic bond and not a strong covalent bond. Its action is most evident in aqueous solution. Its role in affecting the properties of the dried polyvinyl materials will be confined to reducing the water solubility or rehydration of the cured product. True polymerization of polyvinyl chains can be visualized as a 3-step process (Sorenson and Campbell, 1961) : (1) initiation of polymerization by an appropriate "initiator", often a free radical; (2) propagation of the polymerization by transfer of a reactive center; and (3) termination of polymerization when new polymerizable units disappear. Most of the polymerization reactions available to the polyvinyl materials will already have occured during their manufacture, which involves the polymerization and emulsification of vinyl acetate monomer units. When monomer units have been exhausted, the ends of the polymers remain in an activated state for relatively long periods. Polymerization may continue if more monomer is added or if water is removed from the emulsion, thereby bringing together small droplets of polymer that had formerly been physically separated. When the linear extension of chains is restricted or exhausted, graft polymerization becomes the dominant means of joining longer chains together. Graft polymerization can be initiated by the process of chain transfer, in which a free radical, removes an atom such as hydrogen from a polymer chain to yield a free radical site for the growth of branches. Suspension polymerization of vinyl acetate is generally carried out with polyvinyl alcohol as a suspension stabilizer.

Linear polyvinyl chains become, or appear to become knotted and knitted as the polymers become more concentrated during the drying process. Separation of polymer strands by bound water of hydration decreases and hydrophobic interaction increases. After complete drying, subsequent penetration of water becomes extremely difficult owing the proximity of chains and the strength of their hydrophobic interactions. In addition, chemical bonds may also form between adjacent chains by graft polymerization.

The following examples more fully illustrate the invention, but it is not intended that the invention be limited to the exact procedures or concentrations utilized. Rather, it is intended that all equivalents obvious to those skilled in the art be included within the scope of the invention.

In all of the following examples the acid and carbonate blowing agent are added separately. Preferrably, the acid is first combined with polyvinyl emulsion. However, the manner in which the compositions are mixed is not important. They are mixed and agitated to cause the reaction to release the alkali cross linking action and the carbon dioxide blowing agent. When the acid, acid salt, and carbonate are solids they may be premixed and added as a unit. Also they may be suspended

in a water miscible non-ionic liquid and added to the emulsion as a liquid.

The following Examples 13 through 28 use Borden's experimental 6-97 emulsion; Examples 29 through 32 use Borden's homopolyraer adhesive base (standard) emulsion; Examples 36 through 52 use Air Products Airflex 400 emulsion.

As used in the examples PVA is polyvinyl acetate; H3Ct is citric acid; KH Tar is potassium bitartrate; HAc is acetic acid and CMC is carboxymethyl cellulose.

In the following examples, it will be noted that by varying the formulation of the ingredients, various different properties of the resulting product can be emphasized. In this regard, density, structural strength, flame resistance and flexibility are the basic properties that are determined by the specific forumations of our composition.

In order to control the density, a low density is achieved by increasing the amount of the blowing agent. In this regard, an increase in the acid/carbonate ratio causes a decrease in the density correspondingly. For a higher density, the amount of the blowing agent is decreased, or the carbonates are increased.

Concerning the structural strength of the resulting product, in general, the higher density materials have better tensile and shear properties.

The flame resistance of the resulting product is better in the higher density resulting materials. In the higher density materials, increased carbonates cause better cross-linking and a better cell structure to occur, and thus the flame resistance is better.

Better flexibility is exhibited in the less dense resulting material. Also, for better flexibility, copolymers, plasticizers and CMC are used variously in the formulations. They are air dryed at room temperature. The more flexible materials may be used for packaging, due to the better cushioning properties.

EXAMPLE 1 100 parts by weight emulsion (PVA) 7 parts by weight NaHCθ3 1 parts by weight H3Ct

Example.1 results in a material that exhibits dense structural properties and possesses excellent flame resistance. It also readily achieves cross-linking.

EXAMPLE 2 100 parts by weight emulsion (PVA) 3 parts by weight aHC03 6 parts by weight KH tartrate

Example 2 results in a material that is similar to that of Example 1, except that, due to the different blowing agent employed, an even stronger and more dense material results.

EXAMPLE 3 100 parts by weight emulsion (PVA) 2.5 parts by weight citric acid (H3Ct) 10 parts by weight sodium bicarbonate (NaHC0₃)

Example 3 results in a general purpose material that exhibits good insulating and packaging properties. It is a homopolymer of medium density, and has good flame resistance.

EXAMPLE 4 100 parts by weight emulsion (PVA-Et) 2.5 parts by weight H3Ct 10 parts by weight NaHCθ3

Example 4 results in a general purpose material that is especially well suited for packaging and has good flexibility. This is an example of a copolymer used with the same blowing agent of Example 3.

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EXAMPLE 5 100 parts by weight emulsion (PVA) 5 parts by weight KH Tar 10 parts by weight NaHCθ₃

Example 5 results in a material that is similar to that of Example 4, except that a different acid is employed. The resulting material is a general purpose material of medium density. It exhibits good flame resistance and flexibility.

EXAMPLE 6 100 parts by weight emulsion (PVA) 5 parts by weight acetic acid (HAc)

5 parts by weight NaHCθ₃

Example 6 results in a composition that exhibits good insulating properties and is flame resistant.

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EXAMPLE 7 100 parts by weight emulsion (PVA) 5 parts by weight Ca (H2P02)2 5 parts by weight NaHCθ3

Example 7 is similar to Example 6, except that a different acid is employed. The resulting composition exhibits similar properties.

EXAMPLE 8 100 parts by weight emulsion (PVA) 5 parts by weight HC1 (6M) 10 parts by weight NaHCθ3

Example 8 is similar to Example 5, except that a different acid is employed with the resulting composition exhibiting similar properties.

EXAMPLE 9

100 parts by weight emulsion (PVA)

3 parts by weight H3Ct

10 parts by weight KH Tar 20 parts by weight NH4HCO3

Example 9 results in a composition that includes a blend of acids, and is a foamy material due to a large amount of blowing agent. It has good insulating properties and low density.

EXAMPLE 10 100 parts by weight emulsion (PVA) 3 parts by weight H₃Ct 10 parts by weight KH Tar 20 parts by weight gCθ₃

Example 10 results in a composition that includes a mixture of acids, and is a foamy, low density material. It is a retarded foaming compound, and thus is well suited for foaming in place due to he slower rate of curing.

EXAMPLE 11 100 parts by weight emulsion (PVA) 3 parts by weight H₃Ct 10 parts by weight KH Tar 20 parts by weight ZnCC*₃

Example 11 is similar to Example 10 in that it is a retarded foaming compound, except that the cure rate is not quite as slow.

EXAMPLE 12 100 parts by weight emulsion (PVA) 10 parts by weight casein 5 parts by weight HAc 8 parts by weight NaHCθ3

Example 12 results in a composition having better structural properties, medium density, and good flame resistance.

EXAMPLE 13 100 parts by weight emulsion (PVA homopolymer) 10 parts by weight N HCθ3

Example 13 is one of the simplest formulations in that it has two ingredients only. It is a dense, low foaming composition, which has good structural properties. It is flame resistant.

The following Examples 14 through 21 are similar to one another and have varying acid/carbonate ratios for a constant amount of blowing agent. For Examples 14 through 21, the density decreases progressively from a structural formulation (Exhibit 14) progressively to a foamy insulating formulation (Exhibit 21) . EXAMPLE 14 100 parts by weight emulsion (PVA homopolymer) 0.5 parts by weight citric acid 9.5 parts by weight NaHCθ₃

10 EXAMPLE 15

100 parts by weight emulsion (PVA homopolymer) 1 parts by weight citric acid 9 parts by weight NaHCθ₃ 15

EXAMPLE 16 100 parts by weight emulsion (PVA homopolymer) 20 2 parts by weight citric acid

8 parts by weight NaHCθ₃

EXAMPLE 17 25 100 parts by weight emulsion (PVA homopolymer)

4 parts by weight citric acid 6 parts by weight N HCθ3

EXAMPLE 18 100 parts by weight emulsion (PVA homopolymer) 5 parts by weight citric acid 5 parts by weight NaHCC*3

EXAMPLE 19 100 parts by weight emulsion (PVA homopolymer) 6 parts by weight citric acid

4 parts by weight NaHCθ3

EXAMPLE 20 100 parts by weight emulsion (PVA homopolymer) 8 parts by weight citric acid 2 parts by weight NaHCC*3

<10167-01.A10> EXAMPLE 21 100 parts by weight emulsion (PVA homopolymer) 9 parts by weight citric acid 1 parts by weight NaHCθ₃

The following Examples 21 through 28 also are similar to one another and are similar to the set of Examples 14 through 21, by having varying acid/carbonate ratios for a constant amount of blowing agent. The difference between the two sets of examples is the use of a different acid, but the results are similar.

EXAMPLE 22

100 parts by weight emulsion (PVA homopolymer) 1 parts by weight KH tartrate 9 parts by weight NaHCθ₃

EXAMPLE 23 100 parts by weight emulsion (PVA homopolymer)

2 parts by weight KH tartrate 8 parts by weight N HCθ3

EXAMPLE 24 100 parts by weight emulsion (PVA homopolymer) 4 parts by weight KH tartrate 6 parts by weight NaHC03

10

EXAMPLE 25 100 parts by weight emulsion (PVA homopolymer) 15 5 parts by weight KH tartrate

5 parts by weight NaHCθ3

EXAMPLE 26 20 100 parts by weight emulsion (PVA homopolymer) 6 parts by weight KHT 4 parts by weight NaHCθ3

25

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EXAMPLE 27 100 parts by weight emulsion (PVA homopolymer) 8 parts by weight KHT 2 parts by weight NaHCθ3

EXAMPLE 28

100 parts by weight emulsion (PVA homopolymer)

9 parts by weight KHT

1 parts by weight NaHCθ3

EXAMPLE 29 100 parts by weight emulsion (PVA homopolymer) 10 parts by weight KHT 20 parts by weight NaHC03

Example 29 results in a composition that includes a large amount of blowing agent and is a good insulator with good flame resistance.

EXAMPLE 30 100 parts by weight emulsion (PVA homopolymer) 5 parts by weight citric acid 10 parts by weight NaHCθ3

Example 30 is similar to Example 18, and results in a composition that exhibits somewhat higher density than Example 29.

EXAMPLE 31 100 parts by weight emulsion (PVA homopolymer) 15 parts by weight HCL (6M)

10 parts by weight NaHCθ3

Example 31 has a large amount of acid, and results in a low density foamy material.

EXAMPLE 32 100 parts by weight emulsion (PVA homopolymer)

25 parts by weight HCL (6M) 10 parts by weight NaHCθ3

Example 32 is similar to Example 31, except that the resulting material is lighter density and more foamy.

In the following Examples 33 through 38, CMC is employed as an additive to provide better flexibility, by increasing the viscosity of the emulsion. Both high grade (high molecular weight— W) and medium grade (medium molecular weight— W) grades of CMC are used. Examples 33 through 38 exhibit good structural properties, and good flexibility. In general, with greater amounts of CMC, a larger amount of thickening of the composition results.

At the beginning of the foaming process, the uncured foam is semi-rigid, and thus stays in place more readily during the foaming process due to the stability of the foam. The first three non-carbonate ingredients can be premixed. Also, the emulsion is a copolymer for Examples 36 through 38, and results in even greater flexibility.

<10167-01.A10> EXAMPLE 33 100 parts by weight emulsion (PVA) 0.3 parts by weight CMC (high MW) 5 parts by weight citric acid 10 parts by weight sodium bicarbonate

EXAMPLE 34 100 parts by weight emulsion (PVA) 10 0.6 parts by weight CMC (medium MW)

5 parts by weight citric acid 10 parts by weight sodium bicarbonate

15 EXAMPLE 35

100 parts by weight emulsion (PVA)

0.6 parts by weight CMC (medium MW)

5 parts by weight citric acid

10 parts by weight NaHCθ3

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EXAMPLE 36 100 parts by weight emulsion (PVA ethylene copolymer)

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2 parts by weight CMC (medium MW) 5 parts by weight citric acid 10 parts by weight NaHCθ3

EXAMPLE 37 100 parts by weight emulsion (PVA ethylene copolymer) 1 parts of weight CMC (medium MW) 5 parts of weight citric acid

10 parts of weight NaHCθ₃

EXAMPLE 38 100 parts by weight emulsion (PVA)

1 parts by weight CMC (medium MW) 4 parts by weight citric acid 10 parts by weight NaHCOs

The following Examples 39-52 are copolymer emulsion formulations for excellent flexibility and packaging properties. Various additives are employed.

EXAMPLE 39 100 parts by weight emulsion (PVA ethylene copolymer) 1 parts by weight CMC (medium MW) 2 parts by weight vermiculite

5 parts by weight citric acid 10 parts by weight NaHCθ3

Example 39 employs CMC for greater flexibility and foam stability. The vermiculite is a spongy light weight substance to help make this composition low in density.

EXAMPLE 40 100 parts by weight emulsion (PVA ethylene copolymer) 3 parts by weight vermiculite 5 parts by weight citric acid 10 parts by weight NaHCθ3

EXAMPLE 41 100 parts by weight emulsion (PVA ethylene copolymer

0.5 parts by weight CMC (high MW)

2 parts by weight vermiculite

5 parts by weight citric acid

10 parts by weight NaHCθ₃

Example 41 includes a smaller quantity of CMC, and yet achieves the same results. Thus, a more efficient foam stabilization and flexibility is achieved.

EXAMPLE 42

100 parts by weight emulsion (PVA ethylene copolymer) 0.5 parts by weight CMC (high MW) 3 parts by weight vermiculite

5 parts by weight citric acid 10 parts by weight aHCθ₃

Example 42 results in a composition that is similar to Example 41, except that Example 42 is less dense.

EXAMPLE 43 100 parts by weight emulsion (PVA ethylene copolymer)

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0.5 parts by weight CMC (high MW)

5 parts by weight citric acid

3 parts by weight wood chips

10 parts by weight NaHCC*3

The wood chips of this example serve as a filler for packaging properties. The composition has improved structure and good flame resistance.

The following Examples 44 through 48 include popcorn in its expanded (popped) form, and is granulated without destroying the fluffiness of the popcorn. The popcorn provides increased cushioning, and thus packaging properties. The compositions exhibit good flexibility and good flame resistance.

The blowing agents are varied. Examples 47 and 48 include CMC and casein as thickners.

The CMC is a foam stabilizer, and the casein o increases the structural strength—both tensile and shear strengths.

EXAMPLE 44 5 100 parts by weight emulsion (PVA ethylene copolymer) -36-

3 parts by weight popcorn (chips)

4 parts by weight citric acid 10 parts by weight NaHCθ3

EXAMPLE 45 100 parts by weight emulsion (PVA ethylene copolymer) 5 parts by weight popcorn (granules) 10 7 parts by weight citric acid

10 parts by weight NaHCθ3

EXAMPLE 46 15 100 parts by weight emulsion (PVA ethylene copolymer) 2 parts by weight popcorn (granules) 5 parts by weight citric acid 10 parts by weight aHCθ3 20

EXAMPLE 47 100 parts by weight emulsion (PVA ethylene copolymer) 25

3 parts by weight popcorn (granules)

1 parts by weight CMC (medium MW)

5 parts by weight citric acid

10 parts by weight NaHCC*₃

EXAMPLE 48 100 parts by weight emulsion (PVA ethylene copolymer) 3 parts by weight popcorn (granules)

3 parts by weight casein 5 parts by weight citric acid 10 parts by weight NaHCθ3

EXAMPLE 49

100 parts by weight emulsion (PVA ethylene copolymer) 5 parts by weight vermiculite 4 parts by weight citric acid

10 parts by weight NaHCθ3

Example 49 includes a large amount of vermiculite, and thus results in a material having low density and good packaging properties.

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EXAMPLE 50 100 parts by weight emulsion (PVA ethylene copolymer) 1 parts by weight CMC (medium MW) 3 parts by weight vermiculite

5 parts by weight citric acid 10 parts by weight NaHCθ₃

Example 50 results in a composition that includes CMC as a thickener, and thus it is similar to Examples 41 and 42.

EXAMPLE 51 100 parts by weight emulsion (PVA ethylene copolymer) 3 parts by weight polyvinyl alcohol 5 parts by weight citric acid 10 parts by weight NaHCC*₃

Example 5 r1 includes a polyvinyl alcohol that makes this composition more rigid with good structural strength. It is water resistant, and thus is weather resistant and well suited for use in high humidity climates.

EXAMPLE 52 100 parts by weight emulsion (PVA ethylene copolymer) 1 parts by weight boric acid 5 parts by weight citric acid

10 parts by weight NaHCθ3

Example 52 includes boric acid, so that rapid cross¬ linking occurs, and thus rapid curing takes place. The foaming is reduced, and thus the resulting material is more dense.

Examples 53 through 55 that follow, employ different acids, and yet exhibit similar properties. Good structural strength and flame^' resistance are exhibited. Example 55 is more flexible and less dense.

EXAMPLE 53

100 parts by weight emulsion (Homopolymer adhesive base - standard)

2 parts by weight Ca (H2Pθ4)2 6 parts by weight NaHC0₃

EXAMPLE 54 100 parts by weight emulsion (Homopolymer adhesive base - standard) 1.5 parts by weight tartaric acid 6 parts by weight NaHCC*3

EXAMPLE 55 100 parts by weight emulsion (Homopolymer adhesive base - standard) 5 parts by weight oleic acid

6 parts by weight NaHCθ3

Examples 56 and 57 that follow are similar to the two-ingredient Example 13, except that different carbonates are employed. Example 57 is foamy and lighter in weight.

EXAMPLE 56

100 parts by weight emulsion (Homopolymer adhesive base - standard) 5 parts by weight NH4HCO3 EXAMPLE 57 100 parts by weight emulsion (Homopolymer adhesive base - standard) 5 parts by weight (NH4)2 ^co ₃

EXAMPLE 58 100 parts by weight emulsion (Homopolymer adhesive base - standard) 1 parts by weight polyvinylalcohol 10 parts by weight KH tartrate 10 parts by weight NaHCθ3

Example 58 results in a compositon that is very foamy and light in weight. It is moisture resistant, due to the polyvinylalcohol, and it is a good insulator.

EXAMPLE 59 100 parts by weight emulsion (Homopolymer adhesive base - standard)

1 parts by weight polyethylene glycol

10 parts by weight KH tartrate

3 parts by weight citric acid

20 parts by weight NaHCθ3

Example 59 results in a composition that has good structural properties, and yet is light weight. It has a more rigid cured foam that dries quickly and retains its shape.

EXAMPLE 60

100 parts by weight emulsion (Homopolymer adhesive base - standard) 10 parts by weight polyethylene glycol

3 parts by weight citric acid 10 _ parts by weight KH tartrate 20 parts by weight NaHCOs

Example 60 is similar to Example 59, except that a larger amount of polyethylene glycol is employed to increase the properties with only a minor increase in weight.

EXAMPLE 61 100 parts by weight emulsion (Homopolymer adhesive base - standard) 5 parts by weight starch (corn) 3 parts by weight citric acid

10 parts by weight KH tartrate 20 parts by weight NaHCθ3

Example 61 includes a corn starch that serves as a thickener, in a similar manner as CMC, but is less expensive. The resulting material is foamy and is flexible.

EXAMPLE 62 100 parts by weight emulsion (Homopolymer adhesive base - standard) 10 parts by weight KH tartrate^" 10 parts by weight NaHCθ3

Example 62 is a two-part liquid, which lends itself to be pumped and sprayed as a paint or a coating.

EXAMPLE 63 100 parts by weight emulsion (polyacrylic) 2 parts by weight citric acid 8 parts by weight NaHCθ3

Example 63 employs another type of emulsion, polyacryliσ. The resulting composition has hard structural properties, high density and good flame resistance.

EXAMPLE 64

50 parts by weight emulsion (Borden

Experimental 6-97 homopolymer) 50 parts by weight emulsion (polyacrylic) 2 parts by weight citric acid

8 parts by weight NaHCθ3

Example 64 is similar to Example 63, except that it is less dense. The emulsions are blended.

EXAMPLE 65 80 parts by weight emulsion (polyacrylic)

20 parts by weight emulsion (casein) 2 parts by weight citric acid 8 parts by weight NaHCθ3

Example 65 is more dense with excellent structural strength. It is hard, and impact resistant. It has good flame resistant properties. The casein possesses good structural strength itself. The emulsions are blended.

In the foregoing examples, the polyacrylic adds hardness properties to our formulation.

Other acids, such as Ca(H2Pθ4)2 and NaH2Pθ4 may also be employed in place of the acids in the foregoing examples.

Generally speaking, most of the following Examples 66-74, have a two-part composition where both parts are liquid. This gives better uniform dispersion when mixed together. However, Example 66 and Example 67 have two- part liquid and solid components,ι with the polyvinyl acetate emulsion being a liquid and the other component containing only solids.. The solids are first combined, and then added to the liquid.

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EXAMPLE 66 100 parts by weight emulsion

(homopolymer PVA) 8 parts by weight sodium phosphate mono basic 6 parts by weight sodium bicarbonate 2 parts by weight sodium borate 1 part by weight citric acid 1 part by weight corn starch

EXAMPLE 67 100 parts by weight emulsion (homopolymer PVA)

5 parts by weight sodium phosphoric acid 10 parts by weight sodium bicarbonate 5 parts by weight sodium borate

5 parts by weight corn starch

In Example 67, the.polyvinyl acetate, sodium phosphoric acid, and corn starch are first combined. Then, the sodium bicarbonate and sodium borate are mixed together and added as a solid activator component.

EXAMPLE 68 100 parts by weight emulsion

(homopolymer PVA) 2 parts by weight sodium phosphoric acid

2 parts by weight corn starch 2 parts by weight sodium borate 4 parts by weight sodium bicarbonate 10 parts by weight corn syrup

In Example 68, a viscous liquid mixture of the corn starch, sodium borate, sodium bicarbonate, and corn syrup, is added as an activator component to a less viscous liquid mixture of the polyvinyl acetate, sodium phosphoric acid, and corn starch.

EXAMPLE 69 100 parts by weight emulsion

(homopolymer PVA) 2 parts by weight sodium phosphoric acid 2 parts by weight corn starch 2 parts by weight sodium borate

4 parts by weight sodium bicarbonate -48-

5 parts by weight corn syrup 5 parts by weight methanol

Example 69 is similar to Example 68, but the methanol results in a less viscous activator component. As with Examples 66-68, the resulting composition somewhat chars under extreme heat, but it does not tend to support combustion.

EXAMPLE 70

100 parts by weight emulsion

(homopolymer PVA) 2 parts by weight phosphoric acid 17 parts by weight CMC aqueous solution (2%) 2 parts by weight sodium bicarbonate 1 part by weight sodium borate

Example 70 results in a composition that exhibits good flame retardation, good cross-linking ability, toughness, and resiliency. It is clear, partly because of a more uniform dispersion. A liquid activator component, comprising a mixture of the CMC, sodium bicarbonate, and sodium borate, is added to the liquid mixture of the polymer emulsion and phosphoric acid. EXAMPLE 71 100 parts by weight emulsion

(homopolymer PVA) 2 parts by weight phosphoric acid

14 parts by weight CMC aqueous solution (2%) 4 parts by weight sodium bicarbonate 2 parts by weight sodium borate

Example 71 results in a composition that exhibits good flame retardation, good cross-linking for toughness and more resiliency, and good expansion so that it exhibits low density. The liquid activator component is more concentrated than in Example 70, resulting in more foaming agent.

EXAMPLE 72

100 parts by weight emulsion

(homopolymer PVA) 2 parts by weight phosphoric acid 22 parts by weight CMC aqueous solution (2%)

4 parts by weight sodium bicarbonate 2 parts by weight sodium borate Example 72 results in a compositon that exhibits good flame retardation, good cross-linking for toughness and more resiliency, and good expansion with properties midway between those of Example 70 and Example 71.

EXAMPLE 73 100 parts by weight emulsion (homopolymer PVA)

2 parts by weight phosphoric acid 14 parts by weight CMC aqueous solution (2%) 4 parts by weight potassium bicarbonate

2 parts by weight sodium borate

Example 73 results in a composition that exhibits properties similar to those of Example 71.

EXAMPLE 74 100 parts by weight emulsion

(homopolymer PVA) 2 parts by weight phosphoric acid 14 parts by weight CMC aqueous solution (2%) 4 parts by weight amonium bicarbonate 2 parts by weight sodium borate

Example 74 results in a compositon that exhibits properties similar to those of Example 73, illustrating that various bicarbonates may be used.

The following Examples 75 through 77 are examples of foaming corapositions, eraploying the polyvinyl acetate emulsion, under the trade name WB 798, sold by Borden Chemical of St. Louis, MO. In each of these examples good curding occurred.

EXAMPLE 75

100 parts by weight emulsion (PVA) 5 parts by weight concentrated phosphoric acid 5 parts by weight sodium borate 10 parts by weight sodium bicarbonate

EXAMPLE 76 100 parts by weight emulsion (PVA) 5 parts by weight potassium hydrogen tartrate 10 parts by weight potassium bicarbonate

EXAMPLE 77

100 parts by weight emulsion (PVA)

5 parts by weight citric acid 10 parts by weight sodium bicarbonate

The following Examples 78 through 83 are of various compositions illustrating a variety of additives and processes for making the inventive products.

EXAMPLE 78 100 parts by weight emulsion (PVA - Borden Chem. WB798) 5 parts by weight phosphoric acid (concentrated)

5 parts by weight sodium tetraborate 10 parts by weight sodium bicarbonate 5 parts by weight corn starch (filler omitted) —or— 20 parts by weight vermiculite (filler omitted)

The mixing procedure included a Part A and a Part B. In Part A, concentrated phosphoric acid was mixed with 100 g of Borden WB798 polyvinyl acetate emulsion, omitting starch or mica filler. In Part B, sodium tetraborate is mixed with 10 g of sodium bicarbonate; the resulting mixtures is then sprinkled into the mixture of Part A, by a thorough manual mixing. Foaming occurs immediately, and then the composigion is permitted to stand 60 minutes at room temperature. The uncured mixture was studied by taking a portion thereof, and dispersing it in a blender with an equal volume of water for 5 minutes, to disrupt the matrix structure, dispel entrained gas bubbles, and permit pouring thereof. The uncured mixture was observed to contain a foamy curd. It was stiff, and non-pourable.

The water dispersion exhibited a foamy curd, similar to soured milk, and had a pH of 7.98 (alkaline) . Curd hysteresis (i.e., redissolves, becomes milky, curd disperses) was experienced when the pH was adjusted to 4 or below with acetic acid.

The other portion of the uncured mixture (not dispersed) was then poured into a disposable polypropylene container, and then heated at 93°C for 16 hours (overnight) .

The cured product was flexible, porous, and yellow in color. The volume decreased during heat curing. EXAMPLE 79 100 parts by weight emulsion (PVA Borden WB798) 5 parts by weight potassium hydrogen tartrate 10 parts by weight sodium bicarbonate

The mixing procedure included a Part A and Part B.

In Part A, potassium hydrogen tartrate was mixed with

100 g of Borden WB798 polyvinyl acetate emulsion. In

Part B, 10 g of sodium bicarbonate was sprinkled into Part A with thorough manual mixing. Foaming occured immediately. The resulting mixture was permitted to stand for 60 minutes at room temperature.

The uncured mixture was dispersed in a blender with an equal volume of water for 5 minutes, to disrupt the matrix structure, dispel entrained gas bubbles, and permit pouring thereof.

The uncured mixture was observed to contain a foamy curd. It was stiff, and non-pourable. The water dispersion exhibited a foamy curd, and had a pH of 7.85. Curd hysteresis was experienced when the pH was adjusted to 4 or below with acetic acid.

The cured product was flexible, pourous, and yellow in color. The volume decreased during curing thereof. EXAMPLE 80 100 parts by weight emulsion (PVA - Air

Products A400H) 5 parts by weight citric acid 10 parts by weight sodium bicarbonate

1 part by weight carboxymethylcellulose (omitted)

The procedure of Example 79 was followed.

Claims

What is claimed is:Claims

1. A process of making a polyvinyl acetate product, comprising: using aqueous emulsion of polyvinyl acetate; conditioning the polyvinyl acetate to produce curds; eliminating a sufficient amount of water and cross- linking the curds;

2. A process according to Claim 1, further including introducing a salt to the aqueous emulsion to form curds;

3. A process according to Claim 1, wherein said conditioning includes adjusting the pH of the emulsion to about 7.0 or above to form curds.

4. A process according to Claim 1, further including introducing a blowing agent to puff up the curds and cause the cross-linking simultaneously.

5. A process according to Claim 2, wherein said puffing is caused by introducing a blowing agent.

6. A polyvinyl product prepared by the process of Claim 1 from a composition comprising:

100 parts by weight PVA homopolymer emulsion; 8 parts by weight sodium phosphate mono basic; 6 parts by weight sodium bicarbonate; 2 parts by weight sodium borate; 1 part by weight citric acid; and

1 part by weight corn starch.

7. A polyvinyl product prepared by the process of Claim 1 from a composition comprising: 100 parts by weight PVA homopolymer emulsion;

5 parts by weight sodium phosphoric acid; 10 parts by weight sodium bicarbonate; 5 parts by weight sodium borate; and 5 parts by weight corn starch.

8. A polyvinyl product prepared by the process of

Claim 1 from a composition comprising:

100 parts by weight PVA homopolymer emulsion;

2 parts by weight sodium phosphoric acid; 2 parts by weight corn starch;

2 parts by weight sodium borate; 5 parts by weight sodium bicarbonate; and 10 parts by weight corn syrup.

9. A polyvinyl product prepared by the process of Claim 1 from a composition comprising: 100 parts by weight PVA homo polymer emulsion; 2 parts by weight sodium phosphoric acid; 2 parts by weight corn starch; 2 parts by weight sodium borate; 4 parts by weight sodium bicarbonate;

5 parts by weight corn syrup; and 5 parts by weight methanol.

10. A polyvinyl product prepared by the process of Claim 1 from a composition comprising: 100 parts by weight polymer emulsion;

2 parts by weight phosphoric acid; 17 parts by weight CMC aqueous solution (2%) ; 2 parts by weight sodium bicarbonate; and

1 part by weight sodium borate.

11. A polyvinyl product prepared by the process of Claim 1 from a composition comprising:

100 parts by weight polymer emulsion;

2 parts by weight phosphoric acid; 14 parts by weight CMC aqueous solution (2%) ;

4 parts by weight sodium bicarbonate; and 2 part by weight sodium borate.

12. A polyvinyl product prepared by the process of Claim 1 from a composition comprising:

100 parts by weight polymer emulsion; 2 parts by weight phosphoric acid; 22 parts by weight CMC aqueous solution (2%) ; 4 parts by weight sodium bicarbonate; and 2 parts by weight sodium borate.

13. A polyvinyl product prepared by the process of Claim 1 from a composition comprising:

100 parts by weight polymer emulsion; 2 parts by weight phosphoric acid;

14 parts by weight CMC aqueous solution (2%) ; 4 parts by weight potassium bicarbonate; and 2 parts by weight sodium borate.

14. A polyvinyl product prepared by the process of Claim 1 from a composition comprising:

100 parts by weight polymer emulsion; 2 parts by weight phosphoric acid; 14 parts by weight CMC aqueous solution (2%) ; o 4 parts by weight amonium bicarbonate; and

2 parts by weight sodium borate.

15. A polyvinyl product prepared from a composition made by the process of Claim 1 from a vinyl polymer and an 5 alkali carbonate foaming agent.

16. The product of Claim 12 wherein the vinyl polymer is selected from the group consisting of polyvinyl acetate, polyvinyl chloride, polyacrylic, polyvinyl acrylate, polyvinyl maleate, polyvinyl phthalate polymers and copolymers and polyvinyl acetate-ethylene copolymers.

17. The product of Claim 13 wherein the foaming agent includes an acid selected from the group consisting of acetic acid, citric acid, hydrochloric acid, oleic acid, tartaric acid, alkali citrate, alkali oleate, alkali tartrate, alkali bitartrate and mixtures thereof, calcium phosphate, and sodium phosphate.

18. The product of Claim 14 wherein the polyvinyl polymer is selected from the group consisting of polyvinyl acetate and polyvinyl acetate-ethylene polymers and the acid is selected from the group consisting of sodium bicarbonate, citric acid, potassium bitartrate and mixtures thereof.

19. The product of Claim 15 wherein the alkali carbonate is selected from the group consisting of sodium bicarbonate, magnesium carbonate, ammonium bicarbonate and zinc carbonate.

20. The product of Claim 16 wherein the composition includes materials selected from fillers, thickners, plasticizers, protective colloids, adhesives, dyes and mixtures thereof.

21. The product of Claim 17 wherein the composition includes materials selected from, carboxymethyl cellulose, casein, starch, vermiculite, wood chips, popcorn, polyvinyl alcohol and mixtures thereof.

22. The product of Claim 17 wherein the composition comprises:

100 parts by weight of a water based emulsion of polymer selected frora the group consisting of polyvinyl acetate and polyvinyl acetate-ethylene polymers;

2-15 parts by weight of the foaming agent;

0-25 parts by weight of cross-linking re agent;

0-20 parts by weight of filler;

0-5 parts by weight of thickners.

23. The product of Claim 19 wherein the composition comprises:

2-20 parts by weight of sodium bicarbonate; 0-10 parts by weight of citric acid.

24. The product of Claim 19 wherein the composition comprises:

2-20 parts by weight of sodium bicarbonate; 1-15 parts by weight of potassium bitartrate.

25. The product of Claim 19 wherein the composition has 100 parts by weight of a water based polyvinyl acetate polymer and one of the compositions selected from the group consisting of, wherein the proportions indicated are parts by weight;

(a) 2.5 citric acid and 10. sodium bicarbonate; (b) 0.5 citric acid and 9.5 sodium bicarbonate;

(c) 1.0 citric acid and 9.0 sodium bicarbonate;

(d) 2.0 citric acid and 9.0 sodium bicarbonate;

(e) 4.0 citric acid and 6.0 sodium bicarbonate;

(f) 5.0 citric acid and 5.0 sodium bicarbonate; (g) 6.0 citric acid and 4.0 sodium bicarbonate;

(h) 8.0 citric acid and 2.0 sodium bicarbonate;

(i) 9.0 citric acid and 1.0 sodium bicarbonate;

(j) 5.0 citric acid and 10. sodium bicarbonate; and

(k) 10. sodium bicarbonate.

26. The product of Claim 19 wherein the composition has 100 parts by weight of a water base polyvinyl acetate polymer and one of the compositions selected from the group consisting of, wherein the proportions indicated are parts by weight;

(a) 1 potassium bitartrate and 9 sodium bicarbonate; (b) 2 potassium bitartrate and 8 sodium bicarbonate;

(c) 4 potassium bitartrate and 6 sodium bicarbonate;

(d) 5 potassium bitartrate and 5 sodium bicarbonate;

(e) 6 potassium bitartrate and 4 sodium bicarbonate;

(f) 8 potassium bitartrate and 2 sodium bicarbonate; (g) 9 potassium bitartrate and 1 sodium bicarbonate;

(h) 10 potassium bitartrate and 20 sodium bicarbonate; and

(i) 5 potassium bitartrate and 10 sodium bicarbonate.

27. The product of Claim 19 wherein the composition has 100 parts by weight of a water based polyvinyl acetate polymer and one of the compositions selected from the group consisting of, wherein the proportions indicated are pares by weight; (a) 5 sodium bicarbonate and 5 acetic acid;

(b) 5 sodium bicarbonate and 5 calcium phosphate;

(σ) 10 sodium bicarbonate and 5 hydrochloric acid;

(d) 10 sodium bicarbonate and 10 hydrochloric acid; and

(e) 10 sodium bicarbonate and 25 hydrochloric acid.

28. The product of Claim 19 wherein the composition has 100 parts by weight of a water based polyvinyl acetate polymer and one of the compositions selected from the group consisting of, wherein the proportions indicated are parts by weight;

(a) 8 sodium bicarbonate, 5 acetic acid, 10 casein?

(b) 10 sodium bicarbonate, 5 citric acid, 0.3 carboxymethyl cellulose; (c) 10 sodium bicarbonate, 5 citric acid, 0.6 carboxymethyl cellulose;

(d) 10 sodium bicarbonate, 5 acetic acid, 2 carboxymethyl cellulose;

(e) 10 sodium bicarbonate, 5 acetic acid, 1 carboxymethyl cellulose; and

(f) 10 sodium bicarbonate, 4 acetic acid, 1 carboxymethyl cellulose.

29. The product of Claim 19 wherein the composition has 100 parts by weight of a water based polyvinyl acetate polymer and one of the compositions selected from the group consisting of, wherein the proportions indicated are parts by weight;

(a) 20 ammonium bicarbonate, 10 potassium bitartrate, 3 citric acid;

(b) 20 magnesium carbonate, 10 potassium bitartrate, 3 citric acid; and (c) 20 zinc carbonate, 10 potassium bitartrate,

3 citric acid.

30. The product of Claim 19 wherein the composition has 100 parts by weight of a water based polyvinyl acetate-ethylene copolymer and one of the compositions selected from the group consisting of, wherein the proportions indicated are parts by weight;

(a) 10 sodium bicarbonate, 2.5 citric acid;

(b) 10 sodium bicarbonate, 5 citric acid, 2 o vermiculite, 1 carboxymethyl cellulose;

I. (c) 10 sodium bicarbonate, 4 citric acid, 5 vermiculite;

(d) 10 sodium bicarbonate, 5 citric acid, 3 vermiculite, 1 carboxymethyl cellulose; and ₅ (e) 10 sodium bicarbonate, 5 citric acid, 2 vermiculite, 1 carboxymethyl cellulose.

31. A multi-part composition made by the process of Claim 1 for preparing a polyvinyl product, wherein the composition contains at least two separate parts which are to be mixed to prepare the product in a manner known per se, said first part comprising a polyvinyl polymer and the second part comprising a carbonate foaming agent selected from the group consisting of alkali carbonates, and alkali bicarbonates.

32. The composition of Claim 28 wherein the foaming agent includes at least one of an acid and acid alkali salt.

33. The composition of Claim 29 wherein the composition is at least two separate parts with the first part containing the polyvinyl polymer and the second part containing the carbonate and the acid, or the acid being combined with the first, second or both first and second parts.

34. The composition of Claim 30 wherein the polyvinyl polymer is selected from the group consisting of polyvinyl acetate and polyvinyl acetate-ethylene copolymers; the acid is selected from the group consisting of citric acid or citrates, potassium bitartrate, alkali borate and mixtures thereof; and the carbonate is selected from the group consisting of sodium bicarbonate, magnesium carbonate, ammonium bicarbonate and zinc carbonate.

35. The composition of Claim 31 wherein the composition includes materials selected frora, carboxymethyl cellulose, casein, vermiculite, starch, wood chips, popcorn, polyvinly alcohol and mixtures thereof.

36. A wallboard at least one side thereof having a layer of paper thereon, said wall board being a foamed polyvinyl polymer produced by the process of Claim 1 from a polyvinyl polymer selected from the group consisting of polyvinyl acetate, polyvinyl and mixtures thereof; an acid compound selected from the group consisting of citric acid, tartaric acid, alkali citrate, alkali bitartrate and mixtures thereof, and a carbonate selected from the group consisting of sodium bicarbonate, ammonium bicarbonate, magnesium carbonate and zinc carbonate.

37. A foamed packing material produced by the process of Claim 1 from a polyvinyl polymer selected from the group consisting of polyvinyl acetate, polyvinyl acetate-ethylene and mixtures thereof, an acid compound selected from the group consisting of citric acid, hydrochloric acid, tartaric acid, alkali citrate, alkali bitartrate and mixtures thereof, and a carbonate selected from the group consisting of sodium bicarbonate, ammonium bicarbonate, magnesium carbonate and zinc carbonate.

38. The product of Claim 1 wherein the composition has 100 parts by weight of a water based emulsion of polymer selected from the groups consisting of polyvinyl acetate and polyvinyl acetate-ethylene polymers;

5 parts by weight concentrated phosphoric acid; 5 parts by weight sodium borate; 10 parts by weight sodium bicarbonate.

39. The product of Claim 1 wherein the composition has 100 parts by weight of a water based emulsion of polymer selected from the groups consisting of polyvinyl acetate and polyvinyl acetate-ethylene polymers;

5 parts by weight potassium hydrogen tartrate; 10 parts by weight potassium bicarbonate

40. The product of Claim 1 wherein the composition has 100 parts by weight of a water based emulsion of polymer selected from the groups consisting of polyvinyl acetate and polyvinyl acetate-ethylene polymers;

5 parts by weight citric acid

10 parts by weight sodium bicarbonate

41. The product of Claim 1 wherein the composition has 100 parts by weight of a water based emulsion of polymer selected frora the groups consisting of polyvinyl acetate and polyvinyl acetate-ethylene polymers;

5 parts by weight phosphoric acid (concentrated)

5 parts by weight sodium tetraborate 10 parts by weight sodium bicarbonate 5 parts by weight corn starch (filler omitted) — or — 20 parts by weight vermiculite (filler omitted)

42. The product of Claim 1 wherein the composition has 100 parts by weight of a water based emulsion of polymer selected from the groups consisting of polyvinyl acetate and polyvinyl acetate-ethylene polymers;

5 parts by weight potassium hydrogen tartrate 10 parts by weight sodium bicarbonate