Polyvinylacetate bubble gum base composition.

0001The present invention relates to bubble gum base compositions and more particularly to bubble gum compositions that exhibit improved textural properties.

0002Bubble gum compositions generally contain a water- insoluble gum base, a water-soluble flavoring liquid and water soluble sweeteners such as sucrose and corn syrup or in sugarless gum, sorbitol, mannitol and artificial sweeteners. Also incorporated within the gum base may be plasticizers or softeners to improve film forming ability, consistency and texture of the gum. The gum base generally contains a natural rubber gum base, a synthetic rubber gum base or mixtures thereof.

0003Several deficiencies with conventional bubble gums have existed, noteably their tendency to be sticky, exhibit bitter taste when chewed, form inconsistent films when being blown so that uniform thick bubbles are not produced and become tight when chewed.

0004Various efforts have been made to modify the well known bubble gum base formulations, by either the deletion of certain ingredients or the inclusion of other ingredients in each case requiring adjustment of the gum base to assure the maintenance of desired textural characteristics.

0005In U.S. Pat. No. 3,984,574 to Comollo a non-tack chewing gum is disclosed which contains as the preferred elastomer a low molecular weight polyisobutylene (molecular weight of 6,000 to 12,000) and/or a higher molecular weight polyisobutylene (molecular weight of 40,000 to 120,000). It is also disclosed that other elastomers may be employed in place of or together with the polyisobutylene, namely, polyisoprene, a copolymer of isobutylene and isoprene, or the copolymer of butadiene and styrene. In addition, polyvinyl acetate having a molecular weight of at least 2,000 is used in amounts up to 55% along with hydrogenated vegetable oil and animal fat added at a level of 5 to 50%. Mono and diglycerides of fatty acids are also present in amounts up to 103. Calcium carbonate is added as a mineral filler to the various compositions proposed.

0006This disclosure is consistent with the earlier prior art disclosing the essential presence of mineral fillers as one of the ingredients needed to obtain non-stick properties in gum compositions and is silent about the use of triacetin or acetylated monoglycerides.

0007Cherukuri et al. in U.S. Pat. No. 4,352,822 discloses a non-SBR composition by use of polyisobutylene elastomers to make a bubble gum having film forming characteristics. The elastomer gum base used a combination of essential ingredients including glyceryl triacetate and acetylated monoglyceride as plasticizers, a polyterpine resin as an anti-tack agent, polyethylene wax and various other conventional chewing gum additives.

0008A hydrophilic-type detackifier is disclosed to be used in amounts of 5 to 60%. This agent is alleged to sorb saliva and become slippery when the gum is chewed. These materials are used even though it is known that they are incompatible with the elastomer and elastomer solvent. An example of a detackifier is a vinyl polymer. such as polyvinyl acetate, polyvinyl butyl ester and copolymers of vinyl esters and vinyl ethers having a molecular weight from about 2,000 to about 10,000 as disclosed by Cherukuri et al.

0009U.S. Pat. No. 4,357,355 to Koch et al is directed to a non-stick bubble gum base composition that can contain non-SBR elastomers. In particular, this patented non- adhesive bubble gum base composition includes a high molecular weight vinyl polymer such as polyvinyl acetate or polyvinyl alcohol, together with an emulsifier, in combination with ingredients such as an elastomer, an oleaginous plasticizer, an elastomer solvent, mineral adjuvants, fatty acids, and others. The polyvinyl acetate employed by Koch et al. has an average molecular weight of about 38,000 to about 94,000 which material is preblended with the gum base elastomers prior to incorporation of the remaining base ingredients. Koch et al. specifically disclose the presence of 5 to 25% by weight of mineral adjuvants, such as calcium carbonate and talc.

0010U. S. Pat. No. 4,387,108 to Koch et al. is directed to a non-stick chewing gum composition which contains the following ingredients: <tables id="tabl0001" num="0001"><img file="EP0242325A2_D0001.tif" /></tables>The vinyl polymer of Koch et al. has a molecular weight of from 3,000 to about 94,000 and includes PVA compounds having molecular weights on the order of 10,000 to 40,000 as well as 50,000 to 75,000.

0011While the prior art compositions have been effective in making non-stick or tack free bubble gums these formulations have either 1) used low molecular weight PVA in combination with other elastomers and fillers to aid film forming ability or 2) have employed high molecular weight PVA with modifying - expansion agents, such as triacetin, likewise in combination with other elastomers and fillers. The first formulations have not been fully effective, have not been consistent film formers and have separated into phases on storage, that is elastomer and elastomer solvent in one phase and the PVA and sorbed waxes and fats in another phase. In contrast, the second type of high molecular weight PVA formulations contained expansion agents to aid in film formation, and in particular triacetin. This plasticizer resulted in a bitter taste when the gum was chewed and upon chewing resulted in a tight chew causing inadequate bubble formation.

0012In accordance with the present invention, a bubble gum base as well as a bubble gum composition have been discovered which have excellent initial and extended chew properties, forms an essentially continuous film, maintains the bubble shape after the bubble has been formed and resists ingredient separation. These aspects are accomplished without the use of a filler material. although fillers may be added if desired.

0013These textural properties have been unexpectedly produced from a unique combination of non-SBR elastomers, a combination of at least two different polyvinyl acetate polymeric materials and an acetylated monoglyceride which has a sponification value above about 400.

0014In a preferred embodiment, the bubble gum base composition, comprises by weight percent a) about 0.5% to about 30% non-SBR elastomer selected from the group consisting of synthetic gums, synthetic elastomers, natural gums, natural elastomers and mixtures thereof, b) a combination of two polyvinyl acetate polymeric materials selected from (1) up to 14% of a polyvinyl acetate having a low molecular weight of about 12.000 to about 16,000 and (2) up to 35% of a polyvinyl acetate having a medium molecular weight from about 35,000 to 55'000 and wherein the mole ratio of the low molecular weight polyvinyl acetate to the medium molecular weight polyvinyl acetate is from 1:2 to 1:45; c) about 5 % to about 12% acetylated monoglyceride having a sponification value above about 400; and d) remainder of a material selected from the group consisting of elastomer solvent, emulsifiers, plasticizers, waxes and mixtures thereof.

0015In another preferred embodiment, a process for preparing a bubble gum base composition has been developed which comprises <ul id="ul0001" list-style="none"><li>A. providing the following ingredients in amounts expressed in percent by weight; <ul id="ul0002" list-style="none"><li>a. about 0.5% to about 30% non-SBR elastomer selected from the group consisting of synthetic gums. synthetic elastomers, natural gums, natural elastomers and mixtures thereof,</li><li>b. a combination of two polyvinyl acetate polymeric materials selected from <ul id="ul0003" list-style="none"><li>(1) up to 14% of a polyvinyl acetate having a low molecular weight of about 12,000 to about 16,000 and</li><li>(2) up to 35% of a polyvinyl acetate having a medium molecular weight about 45,000 to 55,000, and</li></ul></li><li>c) about 5% to about 12% acetylated monoglyceride having a sponification value above about 400, and</li><li>d) remainder of a material selected from the group consisting of elastomer solvent, emulsifiers, plasticizers, waxes and mixtures thereof,</li></ul></li><li>B. Agitating said elastomer by mixing.</li><li>C. Adding the elastomer solvent to the elastomer of step B to form a first mixture,</li><li>D. Adding to said first mixture the combination of polyvinyl acetate polymer materials to form a second mixture, and</li><li>E. Adding to said mixture the remainder of said ingredients wherein all of the ingredients are mixed under agitation to prepare a bubble gum base composition.</li></ul>

0016The elastomers useful in the present gum base composition include those non styrene butadiene rubber (non-SBR) elastomers normally included in gum bases. Illustrative elastomers include synthetic gums or elastomers such as polyisobutylene and isobutylene-isoprene copolymers; natural gums or elastomers such as chicle, natural rubber, jelutong, balata, guttapercha, lechi caspi, sorva or mixtures thereof. Among these, polyisobutylene, isobutylene-isoprene copolymer or mixtures thereof are preferred.

0017A preferred elastomer is a polyisobutylene which has an average molecular weight of 45,000 to 68,000 (determined by the Flory method). Hard elastomers, that is those having a molecular weight around 1 million are not useable in this invention. The low molecular weight polyisobutylene component may be used as a single polyisobutylene material or combination of different polyisobutylene material or combination of different polyisobutylene compounds provided each has a molecular weight within the range defined. The use of a combination of elastomers has been found beneficial to achieve a bubble gum composition having the desired elasticity and texture.

0018The elastomer content employed is in an amount of about 0.5 to about 30%, and preferably about 5 to about 20% by weight of the gum base. When the total amount of elastomer is below 0.5% the base composition lacks elasticity, chewing texture, and cohesiveness whereas at amounts above 30% the formulation is hard and rubbery.

0019Polyvinyl acetate (PVA) is an essential ingredient in the bubble gum base compositions of this invention. The polyvinyl acetate used must comprise a combination of two different types of PVA. The first component is a low molecular weight material having about 12,000 to about 16,000 mean average molecular weight. Such material will have a preferred viscosity of 14 to 16 seconds (ASTM D1200-82 using a Ford cup viscosity procedure). This low molecular weight component is used in amounts up to 14% by weight of the gum base, and preferably from about 5% to about 12% by weight. The second PVA component is a medium molecular weight variety having a mean average molecular weight of about 35,000 to about 55,000. Such material will have a preferred viscosity of 35 to 55 seconds (ASTM designation D1200-82 using a Ford cup viscometer procedure.) This medium molecular weight component is used in amounts up to 35% by weight of the gum base and preferably from about 25% to about 35% by weight. It has been found that the use of a blend of these two PVA components is essential to prepare a bubble gum base that results in a gum composition that has good film forming properties and maintenance of a thick bubble shape. In addition to the required presence of these components, the components must also be present in a particular ratio. In particular the mole ratio of the low molecular weight PVA to the medium molecular weight PVA should be from 1:2 to 1:45. Lower amounts of low molecular weight component result in thicker films that are tight and unable to form effective bubbles. Higher amounts of low molecular weight component form thin bubble films that lack elasticity.

0020As an optional embodiment of this invention, it is possible to employ small amounts of high molecular weight PVA in combination with the low and medium molecular weight components. The useable high molecular weight PVA may be used in amounts of 0 to 5% by weight of the base and has a mean average molecular weight of 65,000 to 95,000. Amounts above 5% result in a tight gum chew character and are unable to form adequate bubble-films in these formulations.

0021In addition to the critical PVA constituents, it has been found essential to employ a particular mild plasticizer, namely an acetylated monoglyceride having a sponification value above about 400 and preferably between about 430 and about 470. Additionally the acetylated monoglyceride has a percent acetylation above 90%. a hydroxyl value below 10 and a Reichert Meissl value above 150 (Food Chemical Codex(FCC) III/P508 and the revision by AOCS). Acetylated monoglycerides having lower sponification values are not effective in the formulations of this invention. Examples of unsuitable compounds include acetylated monoglycerides having sponification values of 278 to 292. 316 to 331, and 370 to 380. The use of this particular acetylated monoglyceride results in a plasticized bubble gum base that may be formed without use of known bitter PVA plasticizers, namely triacetin. The acetylated monoglycerides of this invention are used in amounts of about 5% to about 12% and preferably about 7% to about 10%.

0022In addition to the foregoing essential ingredients, the bubble gum base compositions of this invention includes a variety of traditional ingredients, such as elastomer solvent, emulsifiers, plasticizers, waxes and mixtures thereof.

0023The bubble gum base composition elastomer solvents aid in softening the rubber-component. Such elastomer solvents may comprise methyl-,glycerol-or pentaerythritol- esters of rosins or modified rosins, such as hydrogenated, dimerized or polymerized rosins or mixtures thereof. Examples of elastomer solvents suitable for use herein include the pentaerythritol ester of partially hydrogenated wood rosin, pentaerythritol ester of wood rosin, glycerol ester of partially dimerized rosin, glycerol ester of polymerized rosin, glycerol ester of tall-oil rosin, glycerol ester of wood rosin and partially hydrogenated wood rosin and partially hydrogenated methyl ester of rosin; terpene resins including polyterpene and polymers of alpha-pinene or beta-pinene and mixtures thereof. The_elastomer solvent may be employed in an amount ranging from about 2% to about 18% and preferably about 7% to about 12% by weight of the gum base. Amounts below about 2% cause the unacceptable chew characteristics. Amounts above 18% cause a soft product to be formed which results in a product which sticks to the face.

0024Useful optional emulsifiers in the formulation of this invention include glyceryl monostearate, lecithin, fatty acid monoglycerides, diglycerides, propylene glycol monostearate and mixtures thereof. Glyceryl monostearate is most preferred. When emulsifiers are absent, the formulation has poor stability and lacks acceptance texture. It is believed that the emulsifier aids in bringing the normally immiscible constituents together in such a way that they form a single finely dispersed stable system. This emulsifier improves hydrophilic character. The emulsifier is employed in amounts of about 2% to about 10% and preferably about 4% to about 8% by weight of the base. It has been found that some emulsifiers conventionally used result in the formation of unacceptable base formulations. Exemplary non-useable emulsifiers include glyceryl triacetate.

0025The gum base formulation preferably employs a wax material. The waxes have been found to soften the rubber elastomer mixture and improve elasticity of the chew character. The waxes employed are preferably microcrystalline wax, natural wax, petroleum wax, paraffin wax and mixtures thereof. Useful amounts are from about 5% to about 18% by weight and preferably from about 7% to about 12% by weight of the gum base composition. The waxes employed herein preferably have a melting point above about 170°F in order to obtain a consistent chew property. Use of waxes having lower melting points increases tackiness.

0026A variety of traditional ingredients such as plasticizers or softeners may optionally be added. Such materials are optional and not essential in the present formulation. Such materials include hydrogenated vegetable oils, lanolin, stearic acid, sodium stearate, potassium stearate, glycerine and the like and mixtures thereof. Such materials when incorporated into the gum base obtain a variety of desirable textures and consistency properties. These individual materials are generally employed in amounts of about 6% to about 20% by weight and preferably in amounts of from about 9% to about 17% by weight of the gum base composition. Because of the low molecular weight of these compounds, they are able to penetrate the fundamental structure of the base making it plastic and less viscous.

0027A unique feature of the inventive formulations is their ability to form cohesive products without the use of filler-texturizing agents. Such agents have been described in the prior art as necessary to impart good lubricant and flavor release properties to non-stick gum base products. Because of applicants unique combination of ingredients the inventive formulations are prepared in the essential absence of filler-texturizing agents. The ability to prepare a PVA containing bubble gum without the essential presence of a filler is unexpected. Prior PVA formulations required the presence of the filler to lend cohesiveness to the base to avoid phase separation of the elastomer/elastomer solvent from the PVA and sorbed oils and waxes. In the absence of the filler this separation has been noted to occur almost immediately upon completion of preparing the normal base compositions.

0028Once the bubble gum base is prepared and is ready for blending into a bubble gum composition, the optional filler-texturizing agent may be added in an amount up to 40_% by weight.

0029The manner in which the base constituents are blended is not critical and is performed using standard techniques and equipment known to those skilled in the art. In a typical embodiment the elastomer composition is agitated with an elastomer solvent and/or plasticizers, and/or emulsifiers for a period of about 1 minute to about 30 minutes. Once initial mixing is complete the PVA components are blended into the first mixture. While it is not essential it is preferred to add the medium molecular weight PVA prior to addition of the low molecular weight component. In this manner uniform blending can be achieved without the creation of isolated pockets of PVA within the elastomer. The remaining base constituents may now be added in bulk, incrementally or stepwise while the resulting mixture is blended for a further equivalent period of time.

0030The present bubble gum base may be formulated into a variety of bubble gum products utilizing standard procedures and equipment. A bubble gum composition may be prepared by combining conventional ingredients such as sweeteners, flavors, colorants and the like.

0031The amount of gum base employed will vary depending on such factors as the type of base used, consistency desired and other components used to make the final product. In general, amounts from about 5% to 45% by weight of the final gum base composition are acceptable with preferred amounts of about 15% to about 25% by weight being useable.

0032The sweetening agent may be selected from a wide range of materials including water-soluble agents, water-soluble artificial sweeteners, and dipeptide based sweeteners, including mixtures thereof. Without being limited to particular sweeteners, representative illustrations encompass: <ul id="ul0004" list-style="none"><li>A. Water-soluble sweetening agents such as monosaccharides, disaccharides, and polysaccharides such as xylose, ribose, glucose, mannose, galactose, fructose, dextrose, sucrose, sugar, maltose, partially hydrolyzed starch, or corn syrup solids and sugar alcohols such as sorbitol, xylitol, mannitol and mixtures thereof.</li><li>B. Water-soluble artificial sweeteners such as the soluble saccharin salts, i.e., sodium or calcium saccharin salts, cyclamate salts, acesulfam-K and the like, and the free acid form of saccharin.</li><li>C. Dipeptide based sweeteners such as L-aspartyl-L-phenylalanine methyl ester and materials described in U.S. Pat. No. 3,492,131 and the like.</li></ul>

0033In general, the amount of sweetener will vary with the desired amount of sweeteners selected for a particular bubble gum. This amount will normally be 0.001% to about 90% by weight when using an easily extractable sweetener. The water-soluble sweeteners described in category A above, are preferably used in amounts of about 25% to about 75% by weight, and most preferably from about 50% to about 65% by weight of the final bubble gum composition. In contrast, the artificial sweetener described in categories B and C are used in amounts of about 0.005% to about 5.0% and most preferably about 0.05% to about 2.5% by weight of the final bubble gum composition. These amounts are ordinarily necessary to achieve a desired level of sweetness independent from the flavor level achieved from flavor oils.

0034Flavoring agents well known to the bubble gum art may be added to the chewing gum compositions of the instant invention. These flavoring agents may be chosen from synthetic flavoring liquids and/or oils derived from plants leaves, flowers, fruits and so forth, and combinations thereof. Representative flavoring liquids include: spearmint oil. cinnamon oil. oil of wintergreen (methylsalicylate) and peppermint oils. Also useful are artificial, natural or synthetic fruit flavors such as citrus oil including lemon, orange, grape, lime and grapefruit and fruit essences including apple, strawberry, cherry, pineapple and so forth.

0035The amount of flavoring agent employed is normally a matter of preference subject to such factors as flavor type, base type and strength desired. In general, amounts of about 0.05% to about 2.0% by weight of the final chewing gum composition are usable with amounts of about 0.8% to about 1.5% being preferred.

0036The bubble gum formulations are prepared by conventional methods. An illustrative process involves first melting the gum base at a temperature from about 70° to about 120°C and mixing the gum base in a kettle with a liquid softener and/or a emulsifier for 2 to 8 minutes. To this mixture 2/3 to 3/4 of the sugar ingredients and colors are added and mixing is continued for 1 to 4 minutes. To this mixture the remaining sugar ingredients are added and while mixing is continued, the flavoring agent is slowly added. Mixing is maintained for 1 to 4 minutes. To this mixture a humectant can be added and mixing is continued for 1 to 4 minutes. The gum is discharged from the kettle-and formed into its desired shape such as strips, slabs, chunks, ball ropes and/or center filled.

0037The following examples are given to illustrate the invention, but are not deemed to be limiting thereof. All percentages given throughout the specification are based upon weight unless otherwise indicated, percentages of base components are by weight of the base, whereas bubble gum composition components are by weight of the final chewing gum formulation.

EXAMPLE 1

Inventive Runs I, II and III Comparative Run A

0038This example demonstrates the formation of bubble gum bases according to the invention.

0039To a preheated kettle is added the elastomer which is mixed for 3 minutes under high shear until the mass reaches a temperature of 190°F. To this mass is added an elastomer solvent and mixing continued for 5 minutes. To this first mixture is added_in sequence while mixing is continued the medium molecular weight PVA, low molecular weight PVA. waxes, plasticizer. acetylated monoglyceride having a sponification value above 400. The final mass is blended for about 30 minutes. The final temperature should range from 160°F to 210°F. The molten mass is discharged from the kettle and put into coated pans. The base is allowed to cool and harden before depanning. The ingredients are recited in Table I. <tables id="tabl0002" num="0002"><img file="EP0242325A2_D0002.tif" /></tables>

EXAMPLE 2

INVENTIVE RUNS IV. V AND VI COMPARATIVE RUN B

0040This example demonstrates the formation of bubble gum compositions according to this invention using the base formulations of Example 1.

0041Bubble gum formulations are prepared with the ingredients recited in Table 1. The formulations were prepared by first melting the gum base at a temperature from 70°C to 100°C and mixing the gum base in a kettle with the emulsifier (lecithin) and corn syrup. Mixing is continued for approximately 2 minutes to obtain a homogenous mixture. To this mixture is added the remaining ingredients of Table II and mixing continued for approximately 7 minutes.

0042The gum is discharged from the kettle and formed into chunks and conditioned to room temperature.

0043In order to evaluate the chewing gum formulations, the formulations were subjected to test panel studies with multiple panelists. The results demonstrated that the bubble gum formulations of this invention exhibited better bubble formation,non-stick to face properties, enhanced chew character and flavor taste, that is lack of bitterness. <tables id="tabl0003" num="0003"><img file="EP0242325A2_D0003.tif" /></tables>

EXAMPLE 3

INVENTIVE RUNS VII AND VIII COMPARATIVE RUNS C AND D.

0044This example demonstrates the formation of bubble gum bases according to the procedure of Example 1 using different amounts of PVA. The formulations are set forth in Table III and were made into bubble gum formulations according to Inventive Run V.

0045Comparative Run C produced a product having a tight rubbery chew which exhibited bitterness upon chewing. Com parative Run D produced a thin film that was unable to form a good bubble. Inventive Runs VIII, and IX exhibited good bubble formation, no tightness and no bitterness when chewed. <tables id="tabl0004" num="0004"><img file="EP0242325A2_D0004.tif" /></tables>

EXAMPLE 4

COMPARATIVE RUNS E, F AND G.

0046This example demonstrates the formation of bubble gum bases according to the procedure of Example 1 using compositions of acetylated monoglyceride having different sponification values.

0047The formulations are set forth in Table IV and were made into bubble gum formulations according to Inventive Run V. All of the Comparative Runs formed products that were unacceptable. All had tight chew and were unable to form a bubble.

0048The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications are intended to be included within the scope of the following claims. <tables id="tabl0005" num="0005"><img file="EP0242325A2_D0005.tif" /></tables>