U.S. patent application number 09/789061 was filed with the patent office on 2001-10-25 for blowing agent blends.
This patent application is currently assigned to Atofina Chemicals, Inc.. Invention is credited to Dillon, Douglas R., Wu, Jinhuang.
Application Number | 20010034378 09/789061 |
Document ID | / |
Family ID | 24094819 |
Filed Date | 2001-10-25 |
United States Patent
Application |
20010034378 |
Kind Code |
A1 |
Wu, Jinhuang ; et
al. |
October 25, 2001 |
Blowing agent blends
Abstract
Foam blowing agents blends of 5-50 mole % HCFC-22 and 95-50 mole
% of n-pentane, i-pentane and/or cyclopentane are provided, as are
polyol premixes and polyurethane foam compositi ons containing such
blends.
Inventors: |
Wu, Jinhuang; (King of
Prussia, PA) ; Dillon, Douglas R.; (Norristown,
PA) |
Correspondence
Address: |
Atofina Chemicals, Inc.
Patent Department, 26th Floor
2000 Market Street
Philadelphia
PA
19103-3222
US
|
Assignee: |
Atofina Chemicals, Inc.
|
Family ID: |
24094819 |
Appl. No.: |
09/789061 |
Filed: |
February 16, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09789061 |
Feb 16, 2001 |
|
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09525843 |
Mar 15, 2000 |
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Current U.S.
Class: |
521/131 ;
252/182.24; 252/67; 252/69; 510/408; 510/415 |
Current CPC
Class: |
C08J 2375/04 20130101;
C08J 9/149 20130101; C08J 2203/14 20130101; C08J 2203/142
20130101 |
Class at
Publication: |
521/131 ;
510/408; 510/415; 252/182.24; 252/67; 252/69 |
International
Class: |
C08J 009/06 |
Claims
1. A foam blowing agent composition comprising (a) about 5 to 50
mole % of chlorodifluoromethane and (b) about 95 to 50 mole % of a
pentane selected from the group consisting of one or more of
n-pentane, i-pentane and cyclopentane.
2. The composition of claim 1 wherein the pentane is a mixture of
i-pentane and cyclopentane.
3. A foam blowing agent composition comprising (a) about 5 to 50
mole % of chlorodifluoromethane and (b) about 95 to 50 mole % of a
pentane selected from the group consisting of one or more of
n-pentane and i-pentane.
4. A foam premix composition comprising a polyol and the foam
blowing agent composition of claim 1.
5. A foam premix composition comprising a polyol and the foam
blowing agent composition of claim 2.
6. A foam premix composition comprising a polyol and the foam
blowing agent composition of claim 3.
7. A polyurethane foam composition comprising an isocyanate, a
polyol and the foam blowing agent composition of claim 1, said foam
composition having (a) an A-side which contains the isocyanate and,
optionally, a portion of the foam blowing agent composition and (b)
a B-side which contains the polyol and the balance of the foam
blowing agent composition.
8. A polyurethane foam composition comprising an isocyanate, a
polyol and the foam blowing agent composition of claim 2, said foam
composition having (a) an A-side which contains the isocyanate and,
optionally, a portion of the foam blowing agent composition and (b)
a B-side which contains the polyol and the balance of the foam
blowing agent composition.
9. A polyurethane foam composition comprising an isocyanate, a
polyol and the foam blowing agent composition of claim 3, said foam
composition having (a) an A-side which contains the isocyanate and,
optionally, a portion of the foam blowing agent composition and (b)
a B-side which contains the polyol and the balance of the foam
blowing agent composition.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to foam blowing agent blends of (a)
chlorodifluoromethane ("HCFC-22" or "22") with (b) n-pentane
(n-C5), i-pentane (i-C5) and/or cyclopentane (c-C5) and to polyol
premixes and polyurethane foam compositions containing such
blends.
[0002] Until now, the leading polyurethane foam blowing agent has
been 1,1-dichloro-1-fluoroethane ("141b"), in order to meet the
market place requirements for energy, fire performance and cost. At
the same time, however, 141b has a high ozone depletion potential
("ODP") of about 0.1. Thus, many foam manufacturers are now
investigating the lower ODP pentanes as candidates to replace 141b,
as noted for example in an article on "Hydrocarbon Blown Rigid
Polyurethane Foam for the Boardstock Industry--A novel Approach" by
R. E. Berrier et al which appeared in Polyurethanes Expo 98, Sep.
17-20, 1998. They too, however, have property shortcomings for use
in foam, such as high cost and high k-factor performance in foam
(thus giving foams with poor thermal insulating properties).
[0003] HCFC-22 has also been disclosed, as in U.S. Pat. No.
4,636,529) for use as a foam blowing agent agent. When used alone,
it has certain disadvantages such as a high global warming
potential ("GWP") of about 1700 and an ODP of about 0.055.
[0004] It would therefore be useful to provide the industry with an
alternative foam blowing agent which overcomes the deficiencies of
22 or the pentanes alone in terms of properties such as ODP, GWP,
cost, and k-factor performance.
BRIEF SUMMARY OF THE INVENTION
[0005] Foam blowing agent compositions are provided, which
compositions comprise (a) about 5 to 50 mole % of
chlorodifluoromethane and (b) about 95 to 50 mole % of a pentane
selected from the group consisting of one or more of n-pentane,
i-pentane and cyclopentane, as well as foam premix compositions,
which premix compositions comprise a polyol and the foregoing
blowing agent blend, and polyurethane foam compositions, which foam
compositions comprise an A-side containing an isocyanate and a
B-side containing a polyol and all or a portion of the foregoing
blowing agent blend.
DETAILED DESCRIPTION
[0006] It has now been found that the foregoing blends of pentanes
with HCFC-22 overcomes deficiencies associated with the use of
either alone. Most important, as shown below, the addition of
relatively small amounts of 22 has been found to lower the k-factor
(and thus enhance the thermal insulating properties) of foams made
with such blends relative to the use of the pentanes alone, while
still taking advantage of the low ODP (zero) and GWP properties of
the pentanes (for example, cyclopentane has a GWP of 11 versus a
GWP of 1700 for 22 alone). Other advantages include lowering of the
cost of use of pentanes alone (especially cyclopentane), improved
solubility in raw materials such as polyester polyols (especially
for n-pentane and i-pentane) and less volatile organic compound
("VOC") content than pure hydrocarbon since HCFC-22 is not a
VOC.
[0007] The unexpected improvement shown in the following examples
in low temperature (0.degree. C.) k-factor performance is
particularly significant for many foam applications such as for
refrigerators, freezers and cold storage facilities.
[0008] The preferred amount of 22 in the blends varies with the
particular pentane or pentane mixture, as shown by the examples
below, but is generally in the 10-35 mole % range.
[0009] In the premix compositions, the blowing agent blend is
typically present in a concentration range of about 2-60 weight %
(preferably 5-40 weight %), based on the weight of the polyol.
[0010] In the polyurethane foam compositions, the effective
concentrations of the blends are typically about 0.1-25 weight %
(preferably 0.5-15%) based on the weight of the total polyurethane
foam formulation.
[0011] The pentane component and/or the 22 component of the blend
can be added to the A-side or the B-side or a portion thereof
distributed in each side. It is also possible to add the blowing
agent composition as a third stream to the foam machine, wholly
apart from the A- or B-side.
[0012] The other components of the premix and foam formulations may
be those which are conventionally used, which components and their
proportions are well known to those skilled in the art. For
example, catalysts, fire retardants and surfactants are typical
components of the B-side.
[0013] The practice of the invention is illustrated in more detail
in the following non-limiting examples. The formulations used (all
having an Iso Index of 300) each contained 170.51 parts M-489, a
polymeric methane diphenyl diisocyanate available from Bayer
Corporation; 100 parts T-2541, a polyester polyol having a hydroxyl
number of 240 available from Kosa; 0.19 part PC-5 and 0.33 part
PC-46, which are, respectively, pentamethyldiethylenetriamine and
potassium acetate in ethylene glycol, catalysts available from Air
Products; 2.98 parts K-15, potassium octoate in dipropylene glycol,
a catalyst available from Air Products; 2 parts B-8462, a
polysiloxane-polyether copolymer surfactant available from
Goldschmidt Chemical Corporation; 10 parts AB-80, a
tris(1-chloro-2-propyl)phosphate fire retardant available from
Albright & Wilson Americas, Inc; and about 24-25 parts blowing
agents, the exact amounts of which are more particularly set forth
below; all parts are by weight.
[0014] A-side premix components, containing isocyanate and 75% of
the blowing agent, were mixed and cooled to 10.degree. C. B-side
premix components, containing polyol, surfactant, fire retardant,
and 25% of the blowing agent, were also mixed and cooled to
10.degree. C.
1TABLE I Parts of Blowing Agent in Comparative Examples with only
Pentane Blowing Agent i-C5: 24.91 9.96 -- -- c-C5: -- 14.53 24.23
-- n-C5: -- -- -- 24.91
[0015]
2TABLE II Parts of Blowing Agent in Invention Examples with 10 Mole
%* 22 in Blowing Agent Blend i-C5: 22.43 8.97 -- -- c-C5: -- 13.08
21.80 -- n-C5: -- -- -- 22.43 HCFC-22: 2.99 2.99 2.99 2.99 *For
examples with 5, 15 and 20 mole % of HCFC-22, the proportional
amount of 22 relative to the pentane content was varied
[0016] In making the foam, the A and B side premixes were mixed for
20 seconds, followed by injection of the catalyst mixture. Mixing
was continued for 15 seconds (except for the i-C5/22 blend, for
which the mixing continued for only 10 seconds in order to reduce
frothing), after which the mixture was poured into a box.
[0017] ASTM procedures were then followed to measure (initial)
k-factors (ASTM C518) of the resultant foams at ambient temperature
(24.degree. C.) and at 0.degree. C. The results are shown in Tables
III and IV:
3TABLE III K-factors (in BTU.in/ft.sup.2.hr..degree- . F.) at
24.degree. C. (% s in blends are in mole %) For 100% n-C5: 0.173
For 5%/95% blend 0.171 of 22/n-C5: For 10%/90% blend 0.167 of
22/n-C5: For 100% i-C5: 0.167 For 5%/95% blend 0.164 of 22/i-C5:
For 10%/90% blend 0.164 of 22/i-C5: For 15%/85% blend 0.163 of
22/i-C5: For 100% c-C5: 0.161 For 10%/90% blend 0.161 of 22/i-C5:
For 20%/80% blend 0.154 of 22/i-C5: For 100% of a 0.160 60/40
c-C5/i-C5 blend: For 5%/95% blend 0.160 of 22 with the 60/40
c-C5/i-C5 blend: For 10%/90% blend 0.156 of 22 with the 60/40
c-C5/i-C5 blend: For 20%/80% blend 0.151 of 22 with the 60/40
c-C5/i-C5 blend:
[0018]
4TABLE IV K-factors (in BTU.in/ft.sup.2.hr..degree. F.) at
0.degree. C. (% s in blends are in mole %) For 100% n-C5: 0.192 For
5%/95% blend 0.183 of 22/n-C5: For 10%/90% blend 0.176 of 22/n-C5:
For 100% i-C5: 0.177 For 5%/95% blend 0.165 of 22/i-C5: For 10%/90%
blend 0.160 of 22/i-C5: For 15%/85% blend 0.157 of 22/i-C5: For
100% c-C5: 0.159 For 10%/90% blend 0.156 of 22/i-C5: For 20%/80%
blend 0.147 of 22/i-C5: For 100% of a 0.167 60/40 c-C5/i-C5 blend:
For 5%/95% blend 0.166 of 22 with the 60/40 c-C5/i-C5 blend: For
10%/90% blend 0.157 of 22 with the 60/40 c-C5/i-C5 blend: 0.148 For
20%/80% blend of 22 with the 60/40 c-C5/i-C5 blend:
* * * * *