Polymeric materials
A method of producing a product, for example a stretch blow moulded container having a metallic or pearlescent appearance, comprises selecting a mass, for example a container preform, comprising a thermoplastic polymer which incorporates a carrier polymer and stretching the thermoplastic polymer during production of said product, for example from said mass. Said carrier polymer is suitably polydimethylsiloxane and the mass may be made in a process which comprises contacting a thermoplastic polymer with a liquid formulation comprising carrier polymer and colourant.
1. A method of producing a product, the method comprising:
a step (i)* which comprises contacting a carrier polymer with a thermoplastic polymer;
a step (i) which follows step (i)* and comprises selecting a mass comprising said thermoplastic polymer which incorporates said carrier polymer, wherein said carrier polymer includes oxygen atoms and silicon atoms in its backbone; and
a step (ii) which comprises stretching the thermoplastic polymer during production of said product from said mass.
2. A method according to claim 1 , wherein said carrier polymer is a polydialkylsiloxane.
3. A method according to claim 1 , wherein said carrier polymer includes a repeat unit of formula
wherein R 1 and R 2 both represent C 1-2 un-substituted alkyl moieties.
4. A method according to claim 1 , wherein said carrier polymer is polydimethylsiloxane.
5. A method according to claim 1 , wherein step (i)* of the method takes place in a melt-processing apparatus and said carrier polymer is dosed into said thermoplastic polymer when said thermoplastic polymer is in a molten state.
6. A method according to claim 5 , wherein said thermoplastic polymer is contacted with a formulation which comprises said carrier polymer, wherein said formulation comprises:
(i) said carrier polymer; and
(ii) a colourant;
wherein said formulation is a liquid.
7. A method according to claim 6 , wherein said formulation includes 0 wt % of laminar or plate-like pigments; includes 0 wt % of metallic colourant; and includes 0 wt % of pearlescent colourant.
8. A method according to claim 6 , wherein at least 95 wt % of the total amount of colourant(s) in said formulation have a maximum dimension which is less than 200 μm.
9. A method according to claim 6 , wherein said formulation comprises 80 to 99 wt % of polydimethylsiloxane and 1 to 20 wt % in total of one or more colourants.
10. A method according to claim 6 , wherein, in said formulation, the sum of the wt % of all carrier polymers which include a repeat unit of formula
wherein R 1 and R 2 both represent C 1-2 un-substituted alkyl moieties and all colourants is at least 95 wt %.
11. A method according to claim 6 , wherein, in said formulation, the sum of the wt % of polydimethylsiloxane and all colourants is at least 98 wt %.
12. A method according to claim 1 , wherein in step (i)* a mixture is formed comprising carrier polymer and thermoplastic polymer and the mass selected in step (i) includes said mixture, wherein said mass includes at least 0.5 wt % of carrier polymer and at least 95 wt % of thermoplastic polymer and said mass includes 0-2 wt % of colourant(s).
13. A method according to claim 1 , wherein, in said mass, the ratio of the wt % of carrier polymer divided by the wt % of thermoplastic polymers is in the range 0.05 to 0.005.
14. A method according to claim 13 , wherein said thermoplastic polymer is a polyester.
15. A method according to claim 1 , wherein a precursor of the product is made and isolated prior to step (ii) of the method, wherein said precursor is a preform for a bottle.
16. A method according to claim 1 , wherein step (ii) comprises stretching the thermoplastic polymer in at least two directions.
17. A method according to claim 1 , which comprises production of a bottle from a preform by contacting thermoplastic polymer with a carrier polymer; injection moulding a mixture comprising the thermoplastic polymer and carrier polymer to produce a preform; and subsequently stretch blow-moulding the preform to produce a product in the form of a bottle.
18. A method of producing a product, the method comprising:
(i) contacting a formulation with a polyester in a melt-processing apparatus to produce a mass comprising said polyester incorporating said formulation, wherein said formulation is dosed into said polyester in a molten state, wherein said formulation is a liquid and comprises a carrier polymer comprising polydimethylsiloxane and a colourant, wherein said formulation includes 0 wt % of laminar or plate-like pigments, includes 0 wt % of metallic colourant and includes 0 wt % of pearlescent colourant, wherein the sum of the wt % of all carrier polymers in said formulation which include a repeat unit of formula
in which R 1 and R 2 both represent C 1-2 un-substituted alkyl moieties and all colourants is at least 95 wt %, and wherein said formulation comprises 80 to 99 wt % of the polydimethylsiloxane and 1 to 20 wt % in total of one or more colourants;
(ii) producing said mass to include at least 0.5 wt % of carrier polymer and at least 95 wt % of thermoplastic polymer and 0-2 wt % of colourant(s) and wherein, in said mass, the ratio of the wt % of carrier polymer divided by the wt % of thermoplastic polymers is in the range 0.05 to 0.005; and
(iii) stretching the thermoplastic polymer in at least two directions during production of said product from said mass;
wherein a precursor of the product comprises a preform for a bottle which is made and isolated prior to step (iii).