CHEWING GUM COMPOSITION

1 . A chewing gum base comprising

i. 1 to 99% by weight of a polymeric material which has a straight or branched chain carbon-carbon backbone and a multiplicity of side chains, and is substantially insoluble in water;

ii. from 0-6% by weight wax;

iii. up to 99% by weight of an elastomeric material different to the polymeric material; and

iv. 0 to 20% by weight of an elastometer;

in which the total amount of polymeric material and elastomeric material is at least 10% by weight of the chewing gum base.

2 . A chewing gum base according to claim 1 , wherein the polymeric material comprises 2-90% by weight of the chewing gum base.

3 . A chewing gum base according to claim 1 , comprising substantially no wax.

4 . A chewing gum base according to claim 1 , wherein the elastomeric material is synthetic or natural rubber.

5 . A chewing gum base according to claim 4 , wherein the elastomeric material is selected from butadiene-styrene copolymers, polyisobutylene and isobutylene-isoprene copolymers.

6 . A chewing gum base according to claim 1 , in which the ratio of elastomeric material plus polymeric material to elastomer plasticiser is at least 5:1.

7 . A chewing gum base according to claim 1 , comprising substantially no elastomer plasticiser.

8 . A chewing gum base according to claim 1 , wherein the elastomer plasticiser comprises methyl, glyceryl or pentaerythrityl esters of rosins or modified rosins, or terpene resins, or mixtures thereof.

9 . A chewing gum base according to claim 1 , additionally comprising a non-toxic vinyl polymer, a filler, a softener and/or an emulsifier.

10 . A chewing gum base according to claim 1 , wherein the backbone of the polymeric material is derived from a homopolymer of an ethylenically unsaturated hydrocarbon monomer or from a copolymer of two or more ethylenically-unsaturated polymerisable hydrocarbon monomers.

11 . A chewing gum base according to claim 10 , wherein the carbon-carbon polymer backbone is derived from a homopolymer of an ethylenically-unsaturated polymerisable hydrocarbon monomer containing 4 or 5 carbon atoms.

12 . A chewing gum base according to claim 11 , wherein the carbon-carbon polymer backbone is derived from a homopolymer of isobutylene.

13 . A chewing gum base according to claim 11 , wherein the carbon-carbon polymer backbone is derived from a homopolymer of butadiene or isoprene.

14 . A chewing gum base according to claim 10 , wherein the carbon-carbon polymer backbone is derived from a copolymer of isobutylene and isoprene.

15 . A chewing gum base according to claim 10 , wherein the carbon-carbon polymer backbone is derived from a butadiene-styrene block copolymer.

16 . A chewing gum base according to claim 1 , wherein the side chains of the polymeric material are derived from poly(ethylene oxide), poly(propylene oxide), polyglycine, poly(vinyl alcohol), poly(styrene sulphonate) or poly(acrylic acid).

17 . A chewing gum base according to claim 16 , wherein the side chains are derived from poly(ethylene oxide) and the backbone is derived from a homopolymer of isoprene.

18 . A chewing gum base according to claim 1 , wherein the side chains are derived from a siloxane, a (poly)silane, a polyalkylsilane, an alkylsilyl polyoxyalkylene or a fluoroalkane.

19 . A chewing gum base according to claim 1 , comprising two or more polymeric materials.

20 . A chewing gum base according to claim 1 , wherein the side chains of the polymeric material have the formula

or have the formula

wherein R 1 is H, —C(O)OR 4 or —C(O)Q and R 2 is —C(O)OR 4 or —C(O)Q

provided that at least one of R 1 and R 2 is the group —C(O)Q;

R 3 is H or —CH 3 ;

R 4 is H or an alkyl group having from 1 to 6 carbon atoms;

Q is a group having the formula —O—(YO) b —(ZO) c —R 5 , wherein each of Y and Z is, independently, an alkylene group having from 2 to 4 carbon atoms and R 5 is H or an alkyl group having from 1 to 4 carbon atoms;

a is 3 or 4, and each of b and c is, independently, 0 or an integer of from 1 to 125 provided that the sum b+c has a value in the range of from 10 to 250.

21 . A chewing gum base according to claim 20 , wherein the side chains in the polymeric material have the formula

wherein Q is as defined in claim 20 .

22 . A chewing gum base according to claim 20 , wherein the side chains in the polymeric material have the formula

wherein Q is as defined in claim 20 .

23 . A chewing gum base according to claim 20 , wherein the side chains in the polymeric material have the formula

wherein one of R 1 and R 2 is —C(O)Q and the other is —C(O)OR 4 , in which Q and R 4 are as defined in claim 20 .

24 . A chewing gum base according to claim 20 , wherein in Q the alkylene groups Y and Z are both —CH 2 CH 2 —.

25 . A chewing gum base according to claim 20 , wherein in Q the group R 5 is H.

26 . A chewing gum base according to claim 20 , wherein in Q the group R 5 is —CH 3 .

27 . A chewing gum base according to claim 20 , wherein in Q the sum b+c has a value in the range of from 40 to 50.

28 . A chewing gum base according to claim 1 , wherein the filler is silica.

29 . A chewing gum composition comprising a chewing gum base according to claim 1 , and one or more sweetening or flavouring agents.

30 . A chewing gum composition according to claim 29 , comprising additional polymeric material, in addition to the chewing gum base, sweetening agent and flavouring agent.

31 . A chewing gum composition according to claim 30 , wherein the additional polymeric material comprises 3-15% by weight of the chewing gum composition.

32 . A chewing gum composition according to claim 29 , comprising 10-50% by weight chewing gum base.

33 . A method for forming a chewing gum base, in which a base is formed comprising:

i. 1 to 99% by weight of the chewing gum base of a polymeric material which has a straight or branched chain carbon-carbon backbone and a multiplicity of side chains, and is substantially insoluble in water;

ii. from 0-6% by weight wax;

iii. up to 99% by weight an elastomeric material excluding the polymeric material; and

iv. up to 20% by weight of an elastomer plasticiser; and

v. optionally a filler;

wherein the total of the amount of polymeric material and elastomeric material is at least 10% by weight of the chewing gum base and wherein the method comprises mixing melted polymeric material, wax (if present), elastomeric material, elastomer plasticiser and filler (if present) to form a gum base.

34 . A method according to claim 33 , comprising a subsequent step in which the gum base is blended with one or more sweetening or flavouring agents to form a chewing gum composition.

35 . A method according to claim 34 , wherein the gum base is blended with one or more sweetening or flavouring agents in molten form to form a blend and the blend is cooled to form a chewing gum composition.

36 . A method according to claim 34 , wherein the gum base is blended with sweetening and flavouring agents and compressed to form a chewing gum composition.

37 . A method according to claim 34 , wherein the chewing gum base comprises 10-50% by weight of the chewing gum composition.

38 . A method for forming a chewing gum base, in which a base is formed comprising:

i. 1 to 99% by weight of the chewing gum base of a polymeric material which has a straight or branched chain carbon-carbon backbone and a multiplicity of side chains, and is substantially insoluble in water;

ii. from 0-6% by weight wax;

iii. up to 99% by weight an elastomeric material excluding the polymeric material; and

iv. up to 20% by weight of an elastomer plasticiser; and

v. optionally a filler;

wherein the total of the amount of polymeric material and elastomeric material is at least 10% by weight of the chewing gum base and wherein the method comprises mixing melted polymeric material, wax (if present), elastomeric material, elastomer plasticiser and filler (if present) to form a gum base, wherein the chewing gum base has the features of claim 2 .