Polyols from phthalic compounds

Polyols containing polyether and polyester moieties, based on phthalic acid are described. A phthalic acid derivative is reacted with a polyether polyol to give the novel polyols which are useful not only in polyisocyanurate foams, but also polyurethane foams as well. The phthalic acid derivative may be phthalic acid, phthalic anhydride and an ester of phthalic acid, for example. The polyester polyol is made from an initiator selected from the group consisting of alkanolamines, alkyleneamines, arylamines, sucrose, glycerin, sorbitol, .alpha.-methylglucoside, .beta.-methylglucoside, and mixtures thereof. The polyester polyol may be made by alkoxylating the initiators.

FIELD OF THE INVENTION 
The invention relates to methods for preparing polyols and more 
particularly relates to methods for preparing polyols useful in preparing 
polyurethane and polyisocyanurate foams, where the polyols are derived 
from phthalic acid derivatives. 
Background of the Invention 
It is known to prepare polyurethane foam by the reaction of a 
polyisocyanate, a polyol and a blowing agent, such as a halogenated 
hydrocarbon, water or both, in the presence of a catalyst. One particular 
area of polyurethane technology is based on rigid polyurethane foams. 
U.S. Pat. No. 4,469,824 to Grigsby, et al., issued Sept. 4, 1984, describes 
polyols produced by reacting scrap polyethylene terephthalate (PET) with 
diethylene glycol and one or more oxyalkylene glycols and stripping out 
some of the ethylene glycol present. The mole ratio of glycols to scrap 
PET is greater than 1.2:1. These polyols are reacted with a polyisocyanate 
to produce polyurethane foams. 
Rigid foams generally have good insulative properties and are thus 
desirable for use in building insulation. As with all building materials, 
it is desirable to provide rigid foams that are as fire resistant as 
possible. One approach to this goal is to modify the polyol. 
Polyisocyanurate foams are a type which are considered to be fire resistant 
and show low smoke evolution on burning. However, polyisocyanurate foams 
tend to be brittle or friable. Various types of polyols have been devised 
to lower the foam friability, but what frequently happens is that the fire 
and smoke properties of the polyisocyanurate foam deteriorate. Thus, a 
fine balance exists between the amount and type of polyol one adds to a 
polyisocyanurate foam formulation in order to maintain maximum flame and 
smoke resistance while at the same time reach a improvement in foam 
friability. U.S. Pat. Nos. 4,039,487 and 4,092,276 describe attempts at 
this fine balance, although each has its disadvantages. 
Scrap polyalkylene terephthlate, such as scrap PET, is known to be 
incorporated into polyurethanes. For example, U.S. Pat. No. 4,048,104 
teaches that polyisocyanate prepolymers for use in polyurethane products 
may be prepared by combining an organic polyisocyanate with polyols which 
are the hydroxyl-terminated digestion products of waste polyalkylene 
terephthalate polymers and organic polyols. A polyol ingredient which is 
the digestion product of polyalkylene terephthalate residues or scraps 
digested with organic polyols is also described in U.S. Pat. No. 
4,223,068. Another example where terephthalic acid residues are employed 
is outlined in U.S. Pat. No. 4,246,365 where polyurethanes are made from 
polyesters containing at least two hydroxyl groups and terephthalic acid 
residues. 
In U.S. Pat. No. 4,237,238 a polyol mixture is prepared by the 
transesterification of a residue from the manufacture of dimethyl 
terephthlate with a glycol, which is then used to produce polyisocyanurate 
foams having a combination of a high degree of fire resistance with low 
smoke evolution, low foam friability and high compressive strength. The 
preparation of such a polyol mixture, such as from ethylene glycol and 
dimethyl terephthalate esterified oxidate residues, is described in U.S. 
Pat. No. 3,647,759. J. M. Hughes and John Clinton, in the Proceedings of 
the S.P.I. 25th Annual Urethane Division Technical Conference, Scottsdale, 
Ariz. October, 1979, describe other foams prepared from the polyols of 
U.S. Pat. No. 3,647,759. 
Another type of polyisocyanurate foam employs a polyol blend using both 
amide diols and primary hydroxyl polyols to give a foam having a high 
reaction exotherm, making it particularly suited to the preparation of 
polyisocyanurate foam laminates, according to U.S. Pat. No. 4,246,364. 
However, another major factor with the use of the polyester polyols 
described above in producing foams is that they have a limited solubility 
in the widely used halogenated hydrocarbon blowing agents, such as 
fluorocarbon 11, which is used to expand the foam and provide its 
insulating characteristics. It would be beneficial if a procedure could be 
found by which these polyester polyols could be made more soluble in 
halogenated hydrocarbon blowing agents. 
Other methods are known for increasing the solubility of these polyester 
polyols in halogenated hydrocarbon blowing agents. For example, U.S. Pat. 
No. 4,642,319 describes modifying recycled polyethylene terephthalate 
polyols with aromatic amino polyols, sucrose polyols, ethoxylated 
alpha-methyl glucosides, alkoxylated glycerine or alkoxylated sorbitol. 
Additionally, U.S. Pat. No. 4,644,019 teaches modifying a recycled 
polyethylene terephthalate polyol with polyethoxylated nonlyphenol to 
increase halogenated hydrocarbon solubility. However, a disadvantage with 
using the ethoxylates of nonylphenol is that the ethoxylate is 
monofunctional, that is, a monofunctional polyester is created. This 
polyester would act as a chain stopper during a polymerization reaction, 
which is not desired. Further, U.S. Pat. No. 4,529,744 shows that 
compatibility agents and polyol blend compositions may be provided 
containing nonionic block ethoxylate propoxylate compounds, amine and 
amine diol compounds, and aromatic ester polyols, especially phthalate 
polyester polyols, which blends are miscible with fluorocarbon blowing 
agents. 
Polyol blend compositions containing nonionic ethoxylate propoxylate 
compounds and aromatic ester polyols, especially phthalate polyester 
polyols, which blends are miscible with fluorocarbon blowing agents are 
taught in U.S. Pat. No. 4,595,711. U.S. Pat. No. 4,644,027 describes 
phthalate polyester polyols containing reaction products of a phthalic 
acid compound, a low molecular weight diol compound and a hydrophobic 
compound are provided which are compatibilized with fluorocarbon blowing 
agents and which possess a variety of other desirable characteristics. 
Other patents which teach self-compatibilizing phthlate-based polyester 
polyols include U.S. Pat. Nos. 4,644,047 and 4,644,048. 
Many other types of polyols useful in the production of polyurethane or 
polyisocyanurate are known. For example, U.S. Pat. No. 4,526,908 describes 
homogeneous liquid polyol blend compositions containing (a) certain 
aliphatic polyols, (b) phthalate diester polyols of these aliphatic 
polyols, and (c) trimellitate polyols of the same aliphatic polyols. The 
resulting polyol blend compositions are useful in making homogeneous 
liquid resin prepolymer blends compositions containing, in addition to 
such a polyol blend, a fluorocarbon blowing agent, a cell stabilizing 
surfactant, and a urethane and/or isocyanurate catalyst. Finally, a unique 
polyol blend of four components is outlined in U.S. Pat. No. 4,544,679 
having (a) 30 to 90 wt.% of a polyester diol having an OH number of from 
about 50 to about 500, (b) 2 to 40 wt.% of an organic compound containing 
from 3 to 8 hydroxyl groups, (c) 5 to 30 wt.% of a condensation product 
formed from 1 mole of a phenol and from 4 to 15 moles of ethylene oxide, 
and (d) 0 to 40 wt.% of another diol. 
Phthalic acid esters made with diethylene glycol are widely used in 
isocyanurate foams, such as in panel line applications. However, the low 
functionality of this type of product limits it use in polyurethane foams. 
It would be advantageous if a polyester polyol could be developed which 
would provide good properties for both polyisocyanurate and polyurethane 
foams. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a new 
class of polyols useful in the preparation of both polyurethane and 
polyisocyanurate foams. 
It is another object of the present invention to provide a new class of 
polyols which will provide polyurethane foams with good dimensional 
stability and K-factors. 
It is yet another object of the invention to provide a new class of polyols 
which will provide polyisocyanurate foams with good performance in small 
scale burn tests. 
In carrying out these and other objects of the invention, there is 
provided, in one form, a method for preparing polyols useful in the 
preparation of polyurethane and polyisocyanurate foams. The method 
involves reacting a phthalic acid derivative with a polyether polyol, 
where the phthalic acid derivative is selected from the group consisting 
of phthalic acid, phthalic anhydride and an ester of phthalic acid and 
where the polyether polyol is made from an initiator selected from the 
group consisting of alkanolamines, alkyleneamines, arylamines, sucrose, 
glycerin, sorbitol, methylglucoside, resins of phenol, aniline and mixed 
phenol aniline, Mannich condensates, and mixtures thereof. 
DETAILED DESCRIPTION OF THE INVENTION 
It has been discovered that novel, useful polyols may be prepared by 
reacting phthalic acid derivatives with various polyether polyols. These 
new polyols are used in preparing both improved polyurethane foams and 
improved isocyanurate foams. The resulting foams exhibit good dimensional 
stability and good K-factors. The isocyanurate foams give good performance 
in small scale burn tests. These new polyols contain both polyether and 
polyester groups, and are based on phthalate acid derivatives. 
These polyols may be prepared by several different methods. 
Method 1. Phthalic anhydride may be reacted with a polyether to form an 
intermediate acid ester which is alkoxylated with an alkylene oxide or an 
alkylene carbonate, such as propylene oxide or propylene carbonate, for 
example. 
##STR1## 
In this method and subsequent methods, the compound HOROH will be taken to 
be a di- or higher hydroxyl compound. The R group symbolizes a variety of 
moieties, such as alkanolamine, alkyleneamine, aryl or aromatic amine, 
sucrose, glycerin, sorbitol, .alpha.-methylglucoside, 
.beta.-methylglucoside and mixtures thereof. Examples of a suitable 
alkanolamine would include, but are not limited to, diethanolamine, 
dipropanolamine, and the like. A suitable arylamine would be 
toluenediamine, for example. An aromatic amino polyol based on a Mannich 
condensate of nonylphenol, formaldehyde, and diethanolamine is also 
suitable. The HOROH polyether polyol should have at least two reactive -OH 
groups present and a polyether moiety, that is, more than one ether moiety 
in the molecule. For example, the HOROH polyether polyol could be 
alkoxylated sucrose, sorbitol, glycerin, methylglucoside, alkanolamines, 
alkoxylated aliphatic amines such as propoxylated 1,3-propanediamines, 
alkoxylated ethyleneamines and propylene amines such as diethylenetriamine 
and the like, alkoxylated arylamines such as 1,4-diaminobenzene and the 
like, alkoxylated resins of phenol, aniline, and mixed phenol aniline like 
methylenedianiline or bisphenol A, and alkoxylated Mannich condensates. 
Method 2. Phthalic anhydride may be reacted with two moles of the polyether 
polyol per mole of anhydride with the removal of water, as symbolically 
represented: 
##STR2## 
Method 3. Phthalic acid may be reacted with one mole of polyol with removal 
of water and then with an alkylene oxide or an alkylene carbonate, as 
illustrated: 
##STR3## 
Method 4. Phthalic acid may be reacted with two moles of polyol with the 
removal of water during the reaction: 
##STR4## 
Method 5. An ester of phthalic acid reacted with one or two moles of a 
polyol, with the removal of glycol or alcohol to produce the modified 
polyester polyol useful in the production of foams: 
##STR5## 
It will be appreciated that the reactions given herein are simplified. For 
example, one contemplated reaction may be diagrammed in simplified form 
as: 
##STR6## 
Whereas, in actuality, an equilibrium exists between the following 
compounds, where y=0, 1, 2 or 3: 
##STR7## 
The equilibrium product would become more complicated as the functionality 
of the polyol reactant increased. In addition, the molar ratio of the 
phthalic moiety to polyol does not have to be 1:1. For example, the moles 
of phthalic residue per mole of polyether polyol may be small or greater 
than one. 
On the other hand, the functionalities preferably should not be equal. That 
is, the reactive ester groups should not equal the reactive hydroxyl 
groups. This reactive group ratio of polyester:polyol may range from 
0.10:1.0 to 0.5:1.0. For example, it is within the scope of this invention 
to react one mole of a polyester of 3 to 4 functionality with a polyol of 
8 functionality. 
The polyether polyol component has already been described. Generally, it is 
derived from an initiator such as alkanolamine, alkylamine, aryl or 
aromatic amine, sucrose, glycerin, sorbitol, .alpha.-methylglucoside, 
.beta.-methylglucoside or other methylglucoside, resins of phenol, aniline 
and mixed phenol aniline, like methylenedianiline or bisphenol A, Mannich 
condensates, and mixtures thereof. Examples of a suitable initiator would 
include, but are not limited to, diethanolamine, dipropanolamine, 
toluenediamine, and the like. The polyether polyol component can be made 
by alkoxylating the initiator with a desired number of moles of an 
alkylene oxide. Preferably, the alkylene oxide has two to four carbon 
atoms, and is thus, ethylene oxide, propylene oxide, butylene oxide or 
mixtures of the oxides. 
The phthalic acid derivative component may be phthalic acid, phthalic 
anhydride, or an ester of phthalic acid, and may be represented as: 
##STR8## 
where in the ester compound, R is an alkylene moiety of from two to four 
carbon atoms, and x ranges from 1 to 4, or R is an alkyl moiety, 
preferably an alkyl moiety of 1 to 4 carbon atoms. 
The reaction of the phthalic acid derivatives with the polyether polyols 
may be conducted in the absence of a catalyst at a temperature ranging 
from about 130.degree. to 220.degree. C., preferably from about 
160.degree. to 210.degree. C. The reaction may be performed at a pressure 
ranging from about atmospheric to about 5 mm Hg, preferably from 
atmospheric to about 10 mm Hg. It will be appreciated that one skilled in 
the art could conduct the inventive reaction at many different pressures, 
and that the reaction pressure is not crucial to the invention. 
The invention will be illustrated further with respect to the following 
examples, which are not intended to limit the scope of the invention.

EXAMPLE 1 
Procedure based on phthalic anhydride: Quantities of 360 grams (2.2 moles) 
of a 1.1 mole propylene oxide adduct of diethanolamine and 296 grams of 
phthalic anhydride were charged to a flask equipped with temperature 
control, a cooling unit, and the stirrer. The contents of the flask were 
heated in the ranged from 130.degree. C. to 160.degree. C. for 1.5 hours. 
At 105.degree. C. to 120.degree. C., 232 grams of propylene oxide and 1 g. 
of dimethylcylohexylamine were charged. The reactants were digested and 
excess propylene oxide was stripped to yield a polyol (Polyol A) with the 
following analyses: 
OH number 428 mg KOH/g. polyol 
Acid number: 0.6 mg KOH/g. polyol 
H.sub.2 O: 0.085% 
Amine: 273 meq/g 
Viscosity: 63,800 cs at 25.degree. C. 
EXAMPLE 2 
Procedure based on a phthalic ester: A polyester prepared from one mole of 
phthalic anhydride and 2 moles of diethylene glycol was used to prepare 
the modified polyester. Quantities of 465 g. of the polyester and 285 
grams of an alkanolamine, prepared from diethanolamine and propylene oxide 
(2 moles), and 0.5 g zinc acetate were charged to a flask equipped with a 
heating mantle, a temperature controller, a distillation head, and vacuum 
capability. The contents of the flask were heated to 190.degree. C. and 76 
grams of diethylene glycol were removed using a vacuum. Fifteen grams of 
ethylene carbonate was charged to the flask, and the contents were cooled 
to 120.degree. C. The flask was evacuated to remove any excess ethylene 
carbonate. The resulting polyol, designated Polyol B, had the following 
analyses: 
OH number: 397 mg KOH/g. polyol 
Acid number: 0.52 mg KOH/g. polyol 
Amine: 1.83 meq/g 
Viscosity: 2,568 cs at 25.degree. C. 
EXAMPLE 3 
A polyol was prepared as in Example 2, except that 306 g. of the polyester 
of Example 2 and 494 g. of a polyether polyol based on a mixture of 
sucrose and glycerin, having an OH number of 520 were used as the 
reactants. The product, designated Polyol C had the following properties. 
OH number: 432 mg KOH/g. polyol 
Acid number: 2.13 mg KOH/g. polyol 
Viscosity: 8,819 cs at 25.degree. C. 
EXAMPLE 4 
Example 2 was repeated, except that 356 g. of the polyester and 429 g. of 
an aromatic aminopolyol based on Mannich condensate of nonylphenol, 
formaldehyde, and diethanolamine were used. A quantity of 51 ml of 
diethylene glycol was removed during the reaction. The resulting polyol, 
Polyol D, had the following analyses: 
OH number: 324 mg KOH/g. polyol 
Acid number: 0.8 mg KOH/g. polyol 
Amine: 1.69 meq/g 
Viscosity: 14,854 cs at 25.degree. C. 
EXAMPLE 5 
This example illustrates the preparation of a polyol of this invention 
using a polyester containing 2 moles of an alkanolamine per mole of 
phthalic ester. Example 2 was repeated, except that 554 g. of the 
polyester and 436 g. of an alkanolamine prepared by the reaction of 
diethanolamine and 2 moles of propylene oxide. During the reaction, 200 
g. of diethylene glycol were stripped. The resulting Polyol E had the 
following properties: 
OH number: 392 mg KOH/g. polyol 
Acid number: 5.53 mg KOH/g. polyol 
Amine: 2.79 meq/g 
Viscosity: 7742 cs at 25.degree. C. 
EXAMPLE 6 
The procedure of Example 2 was repeated, except that 378 g. of the 
polyester and 442 g. of a polyether polyol prepared by the reaction of 
.alpha.-methylglucoside (1 mole) with propylene oxide (2 moles) and 
ethylene oxide (2 moles) were used. During the reaction, 56.23 g. of 
diethylene glycol was removed to give Polyol F with the following 
properties: 
OH number: 441 mg KOH/g. polyol 
Acid number: 1.6 mg KOH/g. polyol 
Viscosity: 4499 cs at 25.degree. C. 
EXAMPLE 7 
Once again, the procedure of Example 2 was repeated, except that 306 g. of 
the polyester and 494 g. of a polyether polyol prepared by reacting 
toluene diamine blocks of ethylene oxide and propylene oxide were 
employed. The polyether polyol had an OH no. of 390. Diethylene glycol 
(45.5 g.) was removed from the reaction to yield Polyol G: 
OH number: 324 mg KOH/g. polyol 
Acid number: 0.3 mg KOH/g. polyol 
Viscosity: 1512 cs at 25.degree. C. 
Foams were prepared by a hand-mix technique, and these foams were poured 
into a box and allowed to cure. Data is given for both polyurethane foams 
and polyisocyanurate foams. The preparation of these types of foams is 
well-known in the art. Generally, the polyols of this invention are 
reacted with a polyisocyanate in the presence of a catalyst, either a 
polyurethane or polyisocyanurate catalyst, depending on the type of foam 
desired. Other components, such as blowing agents or surfactants, may be 
employed to enhance the properties of the foams, as desired. It is 
anticipated that one skilled in the art may optimize the foam formulations 
in which the polyols of the invention may be used. 
TABLE I 
______________________________________ 
Polyurethane Foams 
1 2 3 4 5 
______________________________________ 
Formulations, pbw 
Polyol H* 8.8 9.0 8.7 13.6 9.0 
Polyol A 26.3 -- -- -- -- 
Polyol B -- 27.05 -- -- -- 
Polyol C -- -- 26.28 
-- -- 
Polyol D -- -- -- 25.18 
-- 
Polyol E -- -- -- -- 27.1 
DC-193 0.4 0.4 0.4 0.4 0.4 
Water 0.3 0.3 0.3 0.3 0.3 
THANCAT .RTM. TD-20 
0.1 0.1 0.1 0.1 0.1 
Fluorocarbon 11 11.6 11.6 11.6 11.6 11.6 
Rubinate .RTM. M 52.5 51.55 52.42 
48.62 
51.5 
Reaction Profile 
Cream time (sec) 16 9 11 6 7 
Gel time (sec) 46 25 32 15 24 
Tack free time (sec) 
60 33 45 17 30 
Rise time (sec) 93 56 69 34 51 
Foam Properties 
Density, pcf 1.67 1.62 1.79 1.81 1.76 
K factor 
(BTU-in.)/(hr.-ft.sup.2 -.degree.F.) 
0.106 0.113 0.103 
0.106 
0.108 
Compressive Strength, psi 
45.3 41 41.5 43.3 44.0 
Closed cells, % 94.7 94.2 94.4 93.3 94.5 
Dimensional stability 
% change .DELTA.V 
.DELTA.V 
.DELTA.V 
.DELTA.V 
.DELTA.V 
158 .degree. F., 1 week 
2.5 2.7 2.9 4.4 3.7 
95% R.H., 4 weeks 
3.9 4.7 5.3 9.3 5.8 
______________________________________ 
*A polyol based on ethylene diamine, propylene oxide, and ethylene oxide 
with an hydroxyl number of 780. 
TABLE II 
______________________________________ 
Polyisocyanurate Foams 
6 7 8 9 
______________________________________ 
Formulations, pbw 
Polyol A 21.93 -- -- -- 
Polyol C -- 21.84 -- -- 
Polyol D -- -- 28.6 -- 
Polyol E -- -- -- 23.2 
Surfonic .RTM. N-95 
3.87 3.86 -- 4.1 
DC-193 0.6 0.6 0.6 0.6 
Water 0.5 0.5 0.5 0.5 
Hexchem .RTM. 977 
0.1 0.1 0.1 0.1 
Fluorocarbon 11 13.5 13.5 13.5 13.5 
Dimethylcyclohexylamine 
0.1 0.2 0.1 0.1 
Rubinate .RTM. M 
59.5 59.6 56.7 58.0 
Index 2.5 2.5 2.5 2.5 
Foam Properties 
Density, pcf 1.5 1.75 1.95 1.58 
K factor 
(BTU-in.)/(hr.-ft.sup.2 -.degree.F.) 
0.107 0.126 -- 0.113 
Compressive Strength, psi 
30 25.8 37.4 26.6 
Friability, % 8.3 13.6 12.3 9.7 
Closed cells, % 93.6 89.4 94.2 91.8 
Dimensional stability 
% change, 4 weeks 
.DELTA.V 
.DELTA.V 
.DELTA.V 
.DELTA.V 
158.degree. F., 95% R.H. 
7.7 8.1 11.1 10.1 
95% R.H. 
Butler Chimney Test 
% wt. retained 69.9 79.9 82.9 74.9 
______________________________________ 
______________________________________ 
GLOSSARY 
______________________________________ 
Freon R-11A Fluorocarbon 11, made by 
E. I. du Pont de Nemours, Co. 
Hexchem .RTM. 977 
Potassium octoate in glycol; available 
from Mooney Chemical Co. 
R.H. Relative humidity 
Rubinate .RTM. M 
A 2.7 functional aromatic isocyanate made 
by Rubicon Chemical Co. 
Silicone DC-193 .RTM. 
A silicone surfactant made by Dow- 
Corning Corp. 
Surfonic .RTM. N-95 
The 9.5 molar ethoxylate of nonylphenol, 
sold by Texaco Chemical Co. 
THANCAT .RTM. TD-20 
80 wt. % dimethylamine, 20 wt. % 
triethylenediamine, made by Texaco 
Chemical Co. 
______________________________________ 
The polyols of this invention have increased functionality over other 
polyester polyols, for example, phthalic acid esters made from diethylene 
glycol, that are widely used in isocyanurate foams for panel applications, 
but cannot be used effectively in polyurethane foams. As shown in Tables I 
and II, the foams made from the novel polyester polyols of this invention 
exhibit good dimensional stability and K-factors in both polyurethane and 
polyisocyanurate foams. The isocyanurate foams give good performance in 
small scale burn tests (Butler Chimney Tests). 
Many modifications may be made in the polyester polyols of this invention 
and their method of production without departing from the spirit and scope 
of the invention, which is defined only in the appended claims. For 
example, one skilled in the art could adjust the temperature, pressure, 
reactants, proportions and modes of additions to provide polyester polyols 
that give foams with optimal properties.