Production of polyisocyanurate foam panels

• US 9,987,775 B2
• Filed: 06/24/2016
• Issued: 06/05/2018
• Est. Priority Date: 05/25/2012
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Bertucelli, Luigi, Fantera, Giuseppe, Golini, Paolo
• Primary Examiner(s): YI, STELLA KIM
• Application Number:
  US15/191,675
• Publication Number:
  US 20160303778A1
• Time in Patent Office: 711 Days
• CPC Class Codes: B29C 44/1233 the preformed parts being supported during expanding
• CPC Class Codes: B29C 44/3403 Foaming under special conditions, e.g. in sub-atmospheric pressure, in or on a liquid
• CPC Class Codes: B29C 44/3415 Heating or cooling
• CPC Class Codes: B29C 44/42 using pressure difference, e.g. by injection or by vacuum
• CPC Class Codes: B29K 2075/00 Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/0026 Flame proofing or flame retarding agents
• CPC Class Codes: B29K 2105/04 cellular or porous
• CPC Class Codes: B29L 2009/00 Layered products
• CPC Class Codes: C08G 18/0838 Manufacture of polymers in the presence of non-reactive compounds preparation of compositions C08L75/00
• CPC Class Codes: C08G 18/092 oligomerisation to isocyanurate groups
• CPC Class Codes: C08G 18/14 Manufacture of cellular products
• CPC Class Codes: C08G 18/225 of alkali or alkaline earth metals
• CPC Class Codes: C08G 18/4018 Mixtures of compounds of group C08G18/42 with compounds of group C08G18/48
• CPC Class Codes: C08G 18/4027 Mixtures of compounds of group C08G18/54 with other macromolecular compounds
• CPC Class Codes: C08G 18/4252 derived from polyols containing polyether groups and polycarboxylic acids
• CPC Class Codes: C08G 18/4829 Polyethers containing at least three hydroxy groups C08G18/4833 - C08G18/5096 take precedence
• CPC Class Codes: C08G 18/4879 containing aromatic groups
• CPC Class Codes: C08G 18/4883 containing cyclic groups having at least one oxygen atom in the ring
• CPC Class Codes: C08G 18/546 Oxyalkylated polycondensates of aldehydes
• CPC Class Codes: C08G 18/7664 containing alkylene polyphenyl groups
• CPC Class Codes: C08G 2110/0025 : rigid
• CPC Class Codes: C08G 2110/0058 : ≥50 and <150kg/m3
• CPC Class Codes: C08G 2115/02 : to isocyanurate groups
• CPC Class Codes: C08J 2203/02 : CO2-releasing, e.g. NaHCO3 and citric acid
• CPC Class Codes: C08J 2203/10 : Water or water-releasing compounds
• CPC Class Codes: C08J 2203/12 : Organic compounds only containing carbon, hydrogen and oxygen atoms, e.g. ketone or alcohol
• CPC Class Codes: C08J 2203/14 : Saturated hydrocarbons, e.g. butane; Unspecified hydrocarbons
• CPC Class Codes: C08J 2203/204 : of chemical foaming agent and physical blowing agents
• CPC Class Codes: C08J 2375/06 : from polyesters
• CPC Class Codes: C08J 2375/08 : from polyethers
• CPC Class Codes: C08J 9/0004 : Use of compounding ingredients, the chemical constitution of which is unknown, broadly defined, or irrelevant
• CPC Class Codes: C08J 9/0019 : halogenated
• CPC Class Codes: C08J 9/0038 : containing phosphorus
• CPC Class Codes: C08J 9/08 : developing carbon dioxide
• CPC Class Codes: C08J 9/125 : Water, e.g. hydrated salts
• CPC Class Codes: C08J 9/141 : Hydrocarbons
• CPC Class Codes: Y10T 428/249953 : Composite having voids in a component [e.g., porous, cellular, etc.]

Abstract

The present invention discloses the production of panels by a discontinuous process. The panels are produced by injecting a polyisocyanurate foam forming composition into the mold cavity at reduced pressure. The combination of certain polyisocyanurate foam forming formulation and the reduced pressure in the mold cavity allows production of and resulting sandwich panels in a discontinuous process where the produced panels are characterized by improved fire resistance.

Claims

1. A method of making a polyisocyanurate (PIR) foam, comprising:

A) injecting into a closed mold cavity, wherein said mold cavity is under an absolute pressure of from 300 to 950 mbar, a reaction mixture comprising;

a) an organic polyisocyanate;

b) a polyol mixture, wherein the polyol mixture comprises an aromatic polyester polyol, wherein the aromatic polyester polyol is at least 35 weight percent of the total amount of polyol;

c) a trimerisation catalyst;

d) at least one flame retardant;

e) optionally auxiliary substances; and

f) a blowing agent component,

wherein said reaction mixture has an isocyanate index of greater than 250 and a gel time of at least 50 seconds; and

B) curing to form a polyisocyanurate foam.

2. The method according to claim 1, wherein said closed mold cavity is defined by two exterior shells and an annular frame.

3. The method according to claim 1, wherein the aromatic polyester polyol is at least 50 weight percent of the total amount of polyol.

4. The method according to claim 1, wherein the reaction mixture has an isocyanate index of greater than 350.

5. The method according to claim 1, wherein the mold cavity absolute pressure is from 800 to 950 mbar.

6. The method according to claim 1, wherein the blowing agent component comprises a physical and chemical blowing agent.

7. The method according to claim 6, wherein the chemical blowing agent is water, formic acid or a combination thereof.

8. The method according to claim 6, wherein the physical blowing agent is pentane.

9. The method according to claim 1, wherein the foam has an applied density of 30 to 75 kg/m3.

10. The method according to claim 1, wherein the reaction mixture additionally comprises a silicone surfactant.

11. The method according to claim 1, wherein the flame retardant is a halogen free flame retardant.

12. The method according to claim 1, wherein the aromatic polyester polyol is at least 50 weight percent and less than 80 weight percent of the total amount of polyol.

13. The method according to claim 12, wherein the aromatic polyester polyol is derived from phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, methyl esters of phthalic, isophthalic acid, terephthalic acid, dimethyl terephthalate, trimellitic anhydride, pyromellitic dianhydride, or mixtures thereof.

14. The method according to claim 1, wherein the aromatic polyester polyol is derived from phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, methyl esters of phthalic, isophthalic acid, terephthalic acid, dimethyl terephthalate, trimellitic anhydride, pyromellitic dianhydride, or mixtures thereof.

15. The method according to claim 1, wherein the polyol mixture further includes from 10 to 60 weight percent of a novolac initiated polyether polyol, of the total amount of polyol.