Polyisocyanurate Foams with Flame Retardant Properties and Process for Making the Same

1 . A flame-retardant polyisocyanurate (PIR) foam, the foam comprising the contact product of:

(a) a first reaction composition (A-side) comprising a polyisocyanate component having a viscosity (25° C., mPa·S) of from about 600 cP to about 850 cP and having [1] an isocyanate functionality of from about 2.5 to about 3.5, or [2] an NCO content (wt %) of from about 25 wt % to about 35 wt %; and

(b) a second reaction composition (B-side) comprising:

an aromatic polyester polyol comprising a phthalate-based aromatic content of at least about 30 wt %;

a blowing agent comprising a hydrofluoroolefin (HFO), a hydrochlorofluoroolefin (HCFO), or a combination thereof;

a polyisocyanurate producing catalyst;

a flame retardant; and

a surfactant;

wherein the first reaction composition (A-side) and the second reaction composition (B-side) are used in amounts to provide an A-side:B-side volume ratio (v:v) of from 1.2:1 to 2.2:1; and

wherein the first reaction composition and the second reaction composition are used in amounts to provide an Isocyanate Index of 150 to 375 (expressed as a percentage).

2 . A polyisocyanurate foam according to claim 1 , wherein the polyisocyanate component has an isocyanate functionality of from about 2.8 to about 3.3.

3 . A polyisocyanurate foam according to claim 1 , wherein the polyisocyanate component has an isocyanate functionality of from about 3.0 to about 3.1, an NCO content (wt %) of from about 29 wt % to about 33 wt %, and a viscosity (25° C., mPa·S) of from about 650 cP to about 750 cP.

4 . A polyisocyanurate foam according to claim 1 , wherein the aromatic polyester polyol is characterized by a Hydroxyl Number (mg KOH/g) of from about 150 to about 325.

5 . A polyisocyanurate foam according to claim 1 , wherein the aromatic polyester polyol comprises a phthalate-based aromatic content of from about 30 wt % to about 44 wt % or a phenyl-based aromatic content of from about 17 wt % to about 25 wt %.

6 . A polyisocyanurate foam according to claim 1 , wherein the aromatic polyester polyol comprises Isoexter® TL 250, TEROL® 250, TEROL® 256, TEROL® 305, TEROL® 350, TEROL® 352, TEROL® 563, CARPOL® PES-240, CARPOL® PES-265, CARPOL® PES-295, CARPOL® PES-305, or any combination thereof.

7 . A polyisocyanurate foam according to claim 1 , wherein the blowing agent comprises:

trans-1-chloro-3,3,3-trifluoropropene (HFO-1233zd(E));

trans-1,3,3,3-tetrafluoroprop-1-ene (R-1234ze(E));

cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz-Z);

2,3,3,3-tetrafluoropropene (HFO-1234yf);

2-chloro-3,3,3-trifluoropropene (HCFO-1233xf); or

any combination thereof.

8 . A polyisocyanurate foam according to claim 1 , wherein the blowing agent comprises a hydrofluoroolefin (HFO) blowing agent in combination with a hydrochlorofluoroolefin (HCFO).

9 . A polyisocyanurate foam according to claim 1 , wherein the polyisocyanurate producing catalyst comprises an amine compound, an organometallic catalyst, a metal carboxylate, a metal alkoxide, a metal aryloxide, a metal hydroxide, a tertiary phosphine, a quaternary ammonium salt, or a radical forming agent.

10 . A polyisocyanurate foam according to claim 1 , wherein the flame-retardant comprises a phosphate compound.

11 . A polyisocyanurate foam according to claim 1 , wherein the flame retardant is selected from tris-(2-chloro-1-methylethyl)phosphate (TMCP), low-odor tris-(2-chloro-1-methylethyl)-phosphate (TCPP-LO), tris-(chloroethyl)phosphate (TCEP), tris(chloroisopropyl)phosphate (TCPP), tri-cresyl phosphate (TCP), tris-(1,3-dichloro-2-propyl)phosphate (TDCP), low-viscosity tris-(1,3-dichloro-2-propyl)phosphate (TDCP-LV), TBPA Diol, or combinations thereof.

12 . A polyisocyanurate foam according to claim 1 , wherein the surfactant comprises a non-ionic surfactant, a silicone surfactant, or a combination thereof.

13 . A polyisocyanurate foam according to claim 1 , wherein the first reaction composition (A-side) consists essentially of the polyisocyanate.

14 . A polyisocyanurate foam according to claim 1 , wherein:

the first reaction composition (A-side) comprises the polyisocyanate in a concentration of greater than or equal to 95 wt % of the first reaction composition;

the second reaction composition comprises from about 45 wt % to about 65 wt % of the aromatic polyester polyol, from about 1 wt % to about 10 wt % of the surfactant, from about 8 wt % to about 20 wt % of the blowing agent, from about 1 wt % to about 10 wt % of the polyisocyanurate producing catalyst, and from about 10 wt % to about 30 wt % of the flame-retardant.

15 . A polyisocyanurate foam according to claim 1 , wherein the flame-retardant PIR foam has a density from about 1.5 lb/ft 3 to about 2.5 lb/ft 3 .

16 . A polyisocyanurate foam according to claim 1 , wherein the first reaction composition and the second reaction composition are used in amounts to provide an Isocyanate Index (as a percentage) of 200 to 350.

17 . A polyisocyanurate foam according to claim 1 , wherein the second reaction composition further comprises any one or more of a plasticizer, an emulsifier, a biocide, a bacteriostat, a filler, a dye or colorant, an anti-scorching agent, a cross-linker, an antioxidant, an antistatic agent, or a cell-opening agent.

18 . A polyisocyanurate foam according to claim 1 , wherein the PIR foam passes one or more thermal barrier tests selected from NFPA 286, UL 1715, or a combination thereof, in the presence or in the absence of a protective coating.

19 . A process for making a flame-retardant polyisocyanurate (PIR) foam, the process comprising contacting:

(a) a first reaction composition (A-side) comprising a polyisocyanate component having a viscosity (25° C., mPa·S) of from about 600 cP to about 850 cP and having [1] an isocyanate functionality of from about 2.5 to about 3.5, or [2] an NCO content (wt %) of from about 25 wt % to about 35 wt %; and

(b) a second reaction composition (B-side) comprising:

an aromatic polyester polyol comprising a phthalate-based aromatic content of at least about 30 wt %;

a blowing agent comprising a hydrofluoroolefin (HFO), a hydrochlorofluoroolefin (HCFO), or a combination thereof;

a polyisocyanurate producing catalyst;

a flame-retardant; and

a surfactant;

wherein the first reaction composition (A-side) and the second reaction composition (B-side) are used in amounts to provide an A-side:B-side volume ratio (v:v) of from 1.2:1 to 2.2:1; and

wherein the first reaction composition and the second reaction composition are used in amounts to provide an Isocyanate Index of 150 to 375.

20 . A process for making a polyisocyanurate foam according to claim 19 , wherein:

the polyisocyanate component has an isocyanate functionality of from about 3.0 to about 3.1, an NCO content (wt %) of from about 29 wt % to about 33 wt %, and a viscosity (25° C., mPa·S) of from about 650 cP to about 750 cP; and

the aromatic polyester polyol is characterized by a Hydroxyl Number (mg KOH/g) of from about 150 to about 325.