Process for the production of expandable vinyl aromatic polymer granulate having decreased thermal conductivity

• US 10,639,829 B2
• Filed: 01/14/2016
• Issued: 05/05/2020
• Est. Priority Date: 01/14/2015
• Status: Active Grant

• Current Assignee: Synthos S.A.
• Original Assignee: Synthos S.A.
• Inventors: Kondratowicz, Filip Lukasz, Rojek, Piotr, Mikoszek-Operchalska, Marzena, Utrata, Kamil
• Primary Examiner(s): Boyle, Kara B
• Application Number:
  US15/543,319
• Publication Number:
  US 20180021991A1
• Time in Patent Office: 1,573 Days
• CPC Class Codes: B29B 7/005 for mixing in batches
• CPC Class Codes: B29B 7/244 of several materials
• CPC Class Codes: B29B 7/7485 with consecutive mixers, e.g. with premixing some of the components
• CPC Class Codes: B29B 7/88 Adding charges , i.e. additives
• CPC Class Codes: B29B 7/90 Fillers or reinforcements , e.g. fibres
• CPC Class Codes: B29B 9/065 under-water, e.g. underwater pelletizers
• CPC Class Codes: B29B 9/12 characterised by structure or composition
• CPC Class Codes: B29C 44/3415 Heating or cooling
• CPC Class Codes: B29C 44/3442 Mixing, kneading or conveying the foamable material mixing plastics B29B7/00; mixing in general B01F
• CPC Class Codes: B29C 44/3461 Making or treating expandable particles
• CPC Class Codes: B29C 44/50 using pressure difference, e.g. by extrusion or by spraying B29C44/468 takes precedence
• CPC Class Codes: B29K 2025/00 Use of polymers of vinyl-aromatic compounds or derivatives thereof as moulding material
• CPC Class Codes: B29K 2025/04 Polymers of styrene
• CPC Class Codes: B29K 2025/06 PS, i.e. polystyrene
• CPC Class Codes: B29K 2105/0026 Flame proofing or flame retarding agents
• CPC Class Codes: B29K 2995/0015 Insulating
• CPC Class Codes: B29K 2995/0063 Density
• CPC Class Codes: C08J 2201/022 premixing or pre-blending a part of the components of a foamable composition, e.g. premixing the polyol with the blowing agent, surfactant and catalyst and only adding the isocyanate at the time of foaming
• CPC Class Codes: C08J 2201/03 Extrusion of the foamable blend
• CPC Class Codes: C08J 2325/06 Polystyrene
• CPC Class Codes: C08J 2425/08 : Copolymers of styrene C08J2429/08, C08J2435/06, C08J2455/02 take precedence
• CPC Class Codes: C08J 2471/10 : from phenols
• CPC Class Codes: C08J 9/0014 : Use of organic additives
• CPC Class Codes: C08J 9/0061 : characterized by the use of several polymeric components
• CPC Class Codes: C08J 9/0066 : Use of inorganic compounding ingredients
• CPC Class Codes: C08J 9/18 : by impregnating polymer particles with the blowing agent
• CPC Class Codes: C08J 9/232 : by sintering expandable particles
• CPC Class Codes: Y02P 40/10 : Production of cement, e.g. improving or optimising the production methods; Cement grinding

Abstract

The invention relates to an extrusion process for the production of expandable vinyl aromatic polymer granulate comprising mixing first and second additives with first and second polymer components, respectively, in dedicated mixers.

Claims

1. Extrusion process for the production of expandable vinyl aromatic polymer granulate comprising the steps:

i) feeding a first polymer component comprising vinyl aromatic polymer into a first mixer;

ii) feeding a first additive component a) into the first mixer, to produce a first mixture from the first polymer component and the first additive component;

iii) feeding a second polymer component b) comprising vinyl aromatic polymer into a second mixer;

iv) feeding a second additive component b) into the second mixer, to produce a second mixture from the second polymer component and the second additive component, wherein the processing conditions in the second mixer are more severe than the processing conditions in the first mixer, by providing higher shear force;

v) combining the first and second mixtures, to produce a third mixture;

vi) injecting blowing agent c) into the third mixture, to produce a fourth mixture;

vii) mixing the fourth mixture; and

viii) pelletizing the fourth mixture, to obtain the granulate,

wherein

the process comprises an extrusion;

the first additive component a) comprises one or more of

a1) nucleating agent,

a2) flame retardant,

a3) synergist,

a4) thermal oxidative stabiliser,

a5) flame retardant thermal stabiliser, and

a6) dispersion aid;

the second additive component b) comprises

b1) a mineral constituent comprising geopolymer and/or geopolymer composite and

the second mixer is an extruder or a static mixer.

2. The process of claim 1, wherein the combining v) is a feeding of the second mixture into the first mixer, to produce the third mixture.

3. The process of claim 1, wherein the first mixer is an extruder or a static mixer.

4. The process of claim 1, wherein the temperature in the first mixer is in the range of 100 to 250°

C.

5. The process of claim 1, wherein the second mixer is a co-rotating twin screw extruder.

6. The process of claim 1, wherein vi) the injection is into the third mixture, the third mixture being a melt.

7. The process of claim 1, wherein the second additive component b) comprises one or more powders.

8. The process of claim 1, wherein the second additive component b) consists of both b1) a mineral constituent and b2) a carbonaceous constituent, wherein the carbonaceous constituent b2) is one or more of b2a) carbon black, b2b) graphite, and b2c) coke.

9. The process of claim 1, wherein the mineral constituent b1) further comprises one or more of

b1a) silica,

b1b) calcium phosphate, and

b1c) mineral having perovskite structure.

10. The process of claim 9, wherein

b1a) the silica is amorphous and has

a BET surface of 1 to 100 m²/g,

an average particle size within the range of from 3 nm to 1,000 nm, and

the silica, if used, is present in an amount of 0.01 to less than 2 wt. %, based on the weight of the vinyl aromatic polymer in the granulate (inclusive of solid and, if any, liquid additives, but exclusive of propellant),

b1b) the calcium phosphate has a particle size of 0.01 μ

m to 100 μ

m,

the calcium phosphate, if used, is present in an amount of 0.01 to 50 wt. %, based on the weight of the vinyl aromatic polymer in the granulate (inclusive of solid and, if any, liquid additives, but exclusive of propellant), and

b1c) the mineral having perovskite structure has

a BET surface in a range of from 0.01 to 100 m²/g, and

a particle size in the range of from 0.01 to 100 μ

m, and

the mineral having perovskite structure, if used, is present in an amount of 0.01 to 50 wt. %, based on the weight of the vinyl aromatic polymer in the granulate (inclusive of solid and, if any, liquid additives, but exclusive of propellant).

11. The process of claim 9, wherein the calcium phosphate is tricalcium phosphate.

12. The process of claim 8, wherein the carbonaceous constituent b2) consist of one or both of b2a) carbon black and b2b) graphite.

13. The process of claim 12, wherein

b2a) the carbon black has

a BET surface of more than 40 up to 250 m²/g, as measured according to ASTM 6556, and

a sulphur content in the range of from 50 to 20,000 ppm, as measured according to ASTM D 1619, and

the carbon black is present in an amount of 0.1 to 12 wt. %, based on the weight of the vinyl aromatic polymer in the granulate including solid and, if any, liquid additives, but exclusive of propellant.

14. The process of claim 1, wherein the second polymer component b) comprises a vinyl aromatic polymer that is made from styrene and a sterically hindered styrene comonomer.

15. The process according to claim 1, wherein the combining v), to produce the third mixture, is of

a melt of the first mixture with

a melt of the second mixture from the second mixer.

16. The process according to claim 1, wherein the combining v), to produce the third mixture, is of

a melt of the first mixture with

a masterbatch of the second mixture from the second extruder.

17. The process according to claim 16, wherein the second mixture is first cooled and then reheated, and then combined v) with the first mixture.

18. The process according to claim 1, wherein the severe processing conditions in the second mixer comprise a shear rate in a range of from ⅕

s<sup>−

1</sup> to 1/100 s<sup>−

1</sup>.

19. Expandable vinyl aromatic polymer granulate obtained by the process according to claim 1.

20. Expanded vinyl aromatic polymer foam obtained by expansion of the granulate according to claim 19, the foam having

a density of 8 to 30 kg/m³, and

a thermal conductivity, according to standard ISO 8301, of 25 to 35 mW/Km.

21. The process of claim 1, wherein the combining v) is in the first mixer.

22. The process of claim 1, wherein the first mixer is a co-rotating twin screw extruder.

23. The process of claim 1, wherein the temperature in the first mixer is in the range of 150 to 230°

C.

24. The process of claim 9, wherein

b1a) the silica is amorphous and has

a BET surface of 15 to 30 m²/g,

an average particle size within the range of from 40 to 400 nm, and

the silica, if used, is present in an amount of 0.5 to 1.5 wt. %, based on the weight of the vinyl aromatic polymer in the granulate (inclusive of solid and, if any, liquid additives, but exclusive of propellant),

b1b) the calcium phosphate has a particle size of 0.5 μ

m to 30 μ

m,

the calcium phosphate, if used, is present in an amount of 0.5 to 10 wt. %, based on the weight of the vinyl aromatic polymer in the granulate (inclusive of solid and, if any, liquid additives, but exclusive of propellant), and

b1c) the mineral having perovskite structure has

a BET surface in a range of from 0.1 to 15 m²/g, and

a particle size in the range of from 0.5 to 30 μ

m, and

the mineral having perovskite structure, if used, is present in an amount of 0.5 to 10 wt. %, based on the weight of the vinyl aromatic polymer in the granulate (inclusive of solid and, if any, liquid additives, but exclusive of propellant).

25. The process of claim 12, wherein

b2a) the carbon black has

a BET surface of more than 50 to 100 m²/g, as measured according to ASTM 6556, and

a sulphur content in the range of from 50 to 20,000 ppm, as measured according to ASTM D 1619, and

the carbon black is present in an amount of 3.0 to 6.0 wt. %, based on the weight of the vinyl aromatic polymer in the granulate including solid and, if any, liquid additives, but exclusive of propellant.

26. The process of claim 1, wherein the second polymer component b) comprises a vinyl aromatic polymer that is made from styrene and a sterically hindered styrene comonomer comprising p-tert-butyl styrene.

27. The process of claim 26, wherein the sterically hindered styrene comonomer comprises 1 to 99 wt. % of p-tert-butylstyrene comonomer, based on the total weight of monomer.

28. The process of claim 27, wherein the sterically hindered styrene comonomer comprises 2 to 30 wt. % of p-tert-butylstyrene comonomer, based on the total weight of monomer.

29. The process according to claim 1, wherein the combining v), to produce the third mixture, is of

a melt of the first mixture with

a melt of the second mixture from the second mixer, directly from the second mixer.

30. The process according to claim 1, wherein the combining v), to produce the third mixture, is of

a melt of the first mixture with

a masterbatch of the second mixture from the second extruder, wherein the second mixture is cooled when exiting the second mixer.

31. The process according to claim 1, wherein the severe processing conditions in the second mixer comprise a shear rate in a range of from 1/20 to 1/60 s⁻

1.

32. The process of claim 3, wherein the extruder is a co-rotating twin screw extruder.