A POLYURETHANE FOAM COMPOSITION AND A METHOD FOR SYNTHESIS THEREOF

Abstract

A method for synthesising polyurethane foam compositions convenient for use in areas wherein rigidity and lightness are required together in automotive sector and including the steps of: conduct of polyol dosage adjustment, adding inflating reaction catalyser onto polyol of convenient amount and mixing at mechanical mixture, adding glycerine while mixing is continued, adding surfactive while mixing is continued, adding gelling reaction catalyser while mixing is continued, adding cell opening agent while mixing is continued, adding cell opening agent while mixing is continued, adding at least an inflating agent selected from a group consisting of n-pentane, cyclo-pentane, C.sub.3H.sub.8O.sub.2 gas and C.sub.2H.sub.4O.sub.2 gas while mixing is continued, conduct of temperature adjustment of polyol base mixture, conduct of isocyanide dosage adjustment in a separate place, injecting polyol base mixture into reaction container from one side and isocyanides from other side, conduct of temperature control during reaction and opening mold and removing final product.

Claims

1. A method for polyurethane foam compositions convenient for use in automotive sector where rigidity and lightness are required, comprising process steps of: i. conduct of polyol dosage adjustment, ii. adding inflating reaction catalyser onto polyol of convenient amount and mixing at mechanical mixture, iii. adding glycerine while mixing is continued, iv. adding surfactive while mixing is continued, v. adding gelling reaction catalyser while mixing is continued, vi. adding cell opening agent while mixing is continued, vii. adding monoethylene glycol while mixing is continued, viii. adding at least an inflating agent selected from a group consisting of n-pentane, cyclo-pentane, C.sub.3H.sub.8O.sub.2 gas and C.sub.2H.sub.4O.sub.2 gas while mixing is continued, ix. conduct of temperature adjustment of polyol base mixture, x. conduct of isocyanide dosage adjustment in a separate place, xi. injecting polyol base mixture into reaction container from one side and isocyanides from other side, and xii. conduct of temperature control during reaction and opening mold at the end of reaction and removing final product.

2. The method according to claim 1, wherein the inflating reaction catalyser in process step (ii) is selected from tertiary amines.

3. The method according to claim 1, wherein the surfactive in process step (iv) is silicone.

4. (canceled)

5. The method according to claim 1, wherein the inflating agent in process step (viii) is n-pentane.

6. The method according to claim 1, wherein said adding process in process step (viii) is achieved by help of a pump in a close system.

7. The method according to claim 1, wherein said mixing proves in process step (viii) is made for 15-30 minutes at 400-600 rpm.

8. The method according to claim 1, wherein said temperature adjustment in process step (ix) is made by keeping temperature at 22-28° C. by help of a thermocouple.

9. The method according to claim 1, wherein the mixing polyol base mixture into said reaction in process step (xi) is injected at 140-180 Pa pressure while isocyanide is injected at 130-170 Pa pressure.

10. The method according to claim 1, wherein a temperature of reaction mold in process step (xi) is at range of 42-48° C.

11. A polyurethane foam synthesized by a method according to claim 1, characterized by comprising by weight: 32-34% MDI isocyanides, 50-52% polyether triol, 1-3% cell opening agent, 0.2-0.8% glycerine, 5-7% monoethylene glycol, 0.3-1% gelling reaction catalyser, 0.1-0.4% inflating reaction catalyser, 0.4-0.8% silicon surfactive, and 5-8% n-pentane.

12. The polyurethane foam according to claim 11, wherein said inflating reaction catalyser is an amine catalyser comprising 30% dipropilenglycol by weight.

13. The polyurethane foam according to claim 11, wherein said gelling reaction catalyser is a catalyser comprising 33% triethylene in dipropilenglycol.

14. The polyurethane foam according to claim 11, wherein said cell opening is selected among polyols at KOH numbers 30-35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0036] In this detailed description, a polyurethane foam composition and a method for synthesis thereof being subject of this invention and the preferred applications have been disclosed for the purpose of better understanding of the subject and described in a manner not causing any restrictive effect.

[0037] Invention is a method for polyurethane foam compositions convenient for use in automotive sector where rigidity and lightness are required and comprises process steps of [0038] i. conduct of polyol dosage adjustment, [0039] ii. adding inflating reaction catalyser onto polyol of convenient amount and mixing at mechanical mixture, [0040] iii. adding glycerine while mixing is continued, [0041] iv. adding surfactive while mixing is continued, [0042] v. adding gelling reaction catalyser while mixing is continued, [0043] vi. adding cell opening agent while mixing is continued, [0044] vii. adding mono-ethylene glycol while mixing is continued, [0045] viii. adding at least an inflating agent selected from a group consisting of n-pentane, cyclo-pentane, c.sub.3h.sub.8o.sub.2 gas and c.sub.2h.sub.4o.sub.2 gas while mixing is continued, [0046] ix. conduct of temperature adjustment of polyol base mixture, [0047] x. conduct of isocyanide dosage adjustment in a separate place, [0048] xi. injecting polyol base mixture into reaction container from one side and isocyanides from other side, [0049] xii. conduct of temperature control during reaction and opening mold at the end of reaction and removing final product.

[0050] In a preferred application of the invention, inflating reaction catalyser mentioned in process step numbered (ii) is selected among tertiary amines. According to the most preferred application, amine catalysers comprising 30% dipropilenglycol by weight is preferred as inflating reaction catalyser. In an application, said catalyser is a third amine with commercial title Teogamine BDE.

[0051] Glycerine added into mixture at step (iii) functions as cross-bonding and helps providing dimensional stability of final product. In addition, it has an essential role in adjustment of end product rigidity and elasticity.

[0052] In a preferred application of the invention, surfactive in process step (iv) is silicone. More preferably, silicone surfactive of 1.075±0.01 cm.sup.3 density at room temperature, viscosity 700±150 mPas, 7.4±1.2 pH is preferred. Homogenous and small cell structure is formed to provide final product with high shrinking resistance. In this application, commercial name of said surfactive is TEGOSTAB B 8905.

[0053] In a preferred application of the invention, gelling reaction catalyser mentioned in process step numbered (v) is selected among tertiary amines. According to a preferred application, catalysers comprising 33% dipropylene glycol by weight is preferred as gelling reaction catalyser. In an application, said catalyser is a third amine with commercial title Teogamine 33.

[0054] Cell opening agent added to mixture in process step (vi) enables open cell structure required for sound insulation of end product. In a preferred application of the invention, as cell opening agent polyols with KOH number (mg KOH/g polyol) between 30-35 is used. In an application polyether polyol of commercial title Coranol CP 1421 is used.

[0055] Mono-ethylene glycol added into mixture at step (vii) functions as cross-bonding and helps providing dimensional stability of final product.

[0056] Inflating agents in process step (viii) not only enables inflating reaction but also provides skin formation in end product. In a preferred application of the invention, as inflating agent in process step (viii) n-penthane is used. In said step said adding process is made by help of a pump in close system in order to prevent evaporation of gas. Mixing rate is also essential for keeping gas in the system. In the said step said mixing process continues preferably 15-30 minutes at 400-600 rpm. According to the most preferred application, mixing process continues 20 minutes at 500 rpm.

[0057] In a preferred application of the invention, after process step (ix), temperature of polyol base mixture obtained after adding inflating agent lastly is kept at 22-28° C. by help of thermocouple. This value is preferably 25° C.

[0058] In a preferred application of the invention, in process step (xi) polyol base mixture is injected at 140-180 Pa pressure and isocyanides are injected at 130-170 Pa pressure. The values are preferably 160 Pa for polyol base mixture while 150 Pa for isocyanides. Here another important point is the temperature of reaction container. Temperature of reaction container of the invention is preferably 42-48° C. and the most preferred one is 45° C.

[0059] Temperature of reaction mold in process step (xii) is at range of 42-48° C. Here temperature value is critical in respect to reaching skin thickness of end product. For completion of reaction, it waits for 3 to 7 minutes and at the end of reaction it takes shape of mold, and polyurethane foam is removed from mold.

[0060] Execution of the steps applied in the method of the invention in this order and with such parameters is critical. Particularly, by help of synergy developed by parameters such as selection of inflating agent, speed of mixing it with polyol base mixture, mixing temperature and reaction mold temperature, end product has desired rigidity, lightness and dimensional stability while also long use life of product is achieved, and also a skin with high mechanical strength is achieved.

[0061] The invention is also a polyurethane foam synthesized with said method. In an application of the invention, said polyurethane foam comprises by weight; [0062] 32-34% MDI isocyanides, [0063] 50-52% polyether triol, [0064] 1-3% cell opening agent, [0065] 0.2-0.8% glycerine, [0066] 5-7% monoethylene glycol, [0067] 0.3-1% gelling reaction catalyser, [0068] 0.1-0.4% inflating reaction catalyser, [0069] 0.4-0.8% silicon surfactive, [0070] 5-8% n-pentane.

[0071] In an application of the invention, said polyurethane foam comprises by weight; [0072] 33.8% MDI isocyanides, [0073] 50.6% polyether triol, [0074] 2.2% cell opening agent, [0075] 0.7% glycerine, [0076] 5.4% monoethylene glycol, [0077] 0.4% gelling reaction catalyser, [0078] 0.2% inflating reaction catalyser, [0079] 0.7% silicone surfactive, [0080] 6% n-pentane.

[0081] In above applications of the invention said gelling reaction catalyser and inflating reaction catalyser is in tertiary amine structure. According to the most preferred application, an amine catalyser comprising 30% dipropilenglycol by weight is preferred as inflating reaction catalyser. According to a preferred application, a catalyser comprising 33% dipropylene glycol by weight is preferred as gelling reaction catalyser.

[0082] In a preferred application of the invention, as said cell opening agent polyols with KOH number (mg KOH/g polyol) between 30-35 is selected.

[0083] Polyurethane foam of the invention is achieved as an end product of open cell structure displaying 130-300 gr/dm3 density, skin thickness of 1-2.5 mm, maximum 5% water absorption. Open cell structure and thick skin structure provides high acoustic performance.

[0084] Another importance of the invention is that method of the invention and polyurethane foam synthesized by the method has minimized ecological damage in comparison to its alternatives at present. By help of method of the invention it is possible to produce a polyurethane foam at low cost, not comprising halogen and conforming to global heating regulations.