MXPA99006538A - Mixes of sun agents - Google Patents

Abstract

The present invention relates to: Mixtures of blowing agents of 10-90% n- and / or i-pentane are provided with 90-10% of 142bo124, such as prepolyol mixtures and polyurethane foam compositions containing said mix

Description

MIXES OF BLOWING AGENTS BACKGROUND OF THE INVENTION This invention relates to mixtures of blowing agents of (a) n- and / or i-pentane with (b) 1-chloro-1,1-difluoroethane ("142b") or 2-chloro-1. , 1, 1, 2-tetrafluoroethane ("124"), more particularly to mixtures containing about 10-90% by weight of each of (a) and (b) already polyol pre-mixtures and addition compositions of polyurethane containing said mixtures. So far, the main polyurethane foam blowing agent has been 1,1-dichloro-1-fluoroethane ("141 b"), in order to meet the requirements of placing on the market for energy, fire performance and cost. At the same time, however, 141 b has a high ozone depletion potential ("PAO") of approximately 0.1. Therefore, many foam manufacturers so far are investigating cyclopentane as the primary alternative candidate to replace 141 b. Cyclopentane has PAO from scratch, but also has property drawbacks in terms of fire performance and aging k-factor performance (and therefore, thermal insulation properties). Therefore, it would be useful to provide the industry with a foam blowing agent that overcomes the deficiencies of 141 b and cyclopentane in terms of properties such as PAO, fire performance, aging of the K factor and the like.

While articles have been written about the mixed blowing agents present, such as the Description of Investigation 40137 (9/97) in mixtures of hydrochlorofluorocarbon hydrocarbon, the actual data presented is that the mixtures contain in normal in industry, 141b. BRIEF COMPENDIUM OF THE INVENTION Foam blowing agent compositions are provided, said compositions comprising (a) about 10-90% by weight (preferably 60-80%) of n-pentane, i-pentane or mixtures thereof and ( b) about 90-10% by weight (preferably 40-20%) of 142b or 124, as well as foam pre-mix compositions, said pre-mix compositions comprising a polyol and the above blowing agent mixture and compositions of polyurethane foam, said foam compositions comprise a side A containing a socianate and a side B containing a polyol and all or a portion of the above blowing agent mixture (a portion of the pentane component of the mixture being preferably incorporated on side A). DETAILED DESCRIPTION It has now been found that the above mixtures of n-pentane and / or i-pentane with 142b or 124 overcome the deficiencies associated with 141b or cyclopentane. Therefore, in relation to 141b, the blends of the invention have low PAO by virtue of the low PAO of their components, 0 for n-pentane e -pentane, 0.05 for 142b and 0.02 for 124. In relation to cyclopentane, the use of at least 10% halocarbon (142b or 124) improves fire performance properties, so that less fire retardant is needed and provides foams that not only match the initial K-factor of cyclopentane, but surprisingly they have a slower aging regime which results in improved thermal insulation properties. Mixtures also provide advantages in terms of better resistance to understanding than cyclopentane; the solubility better than the pure hydrocarbon; less VOC (volatile organic compound) than pure hydrocarbon; and better dimensional stability due to the combination of the high-boiling pentanes and the low-boiling halocarbons. In the pre-mix compositions, the blowing agent mixture is usually present in a concentration range of about 2-60% by weight (preferably 10-40% by weight), based on the weight of the polyol. In polyurethane foam compositions, effective concentrations of the blends are usually about 0.1-25% by weight (preferably 0.5-15% by weight) based on the weight of the total polyurethane foam formulation. In order to help solubilize the mixed blowing agent in the polyurethane foam composition, a portion of the pentane component (usually about 50-75%) of the mixture is preferably added to the A side. This also helps to ensure that side A and side B have similar viscosities. The other components of the pre-mix and foam formulations can be those that are conventionally used, said components and their proportions are well known to those skilled in the art. For example, catalysts, retarders and surfactants are normal components of the B side. Some examples of normal components and mixing procedures are shown in the Investigation Description referenced above. The practice of the invention is illustrated in greater detail in the following non-limiting examples of the blowing foams of n-pentane / 142b and n-pentane / 124 compared to a cyclopentane blowing foam. The fomulations used (all having an Iso index of 300) are shown in Table I, all the materials listed being commercially available. In Table I, normal M-489 is polymeric diphenyl methane di-isocyanate, available from Bayer Corporation; T-2541 is a polyester polyol having a hydroxyl number of 240, available from Hoechst Celanese; PC-5 and PC-46 are, respectively, pentamethyldiethylenetriamine and potassium acetate in ethylene glycol, catalysts available from Air Products; K-15 is potassium octoate in dipropylene glycol, a catalyst available from Air Products; B-8462 is a polysiloxane-polyether copolymer, a surfactant available from Goldschmidt Chemical Corporation; and AB-80 is tris (1- chloro-2-propyl) phosphate, a fire retardant available from Albright & Wilson Americas, Inc; all parts are by weight. The components of the A-side pre-mix, containing isocyanate and 75% pentane, were mixed and cooled to 10 ° C. The components of the B-side pre-mix, containing polyol, surfactants, fire retardant, 25% pentane and 100% of any halocarbide, were also mixed and cooled to 10 ° C. Table I To form the foam, the pre-mixtures of sides A and B were mixed for 10 seconds, followed by injection of the catalyst mixture. Mixing was continued for 15 seconds, after which the mixture was poured into a box. The ASTM procedures were followed to measure the K factors (initial and old (ASTM C518) and compression strength (ASTM D 1621) of the resulting foams, all of which had a density of 28,818 g / It. The results are shown in Tables II and III: Table II - K factors (at 0.078 Kcalxcm / hrxcm2x ° C Table l l l - Resistance to Understanding (0.0703 kg / cm)

Claims (20)

1. REVIVAL NAME IS 1. A foam blowing agent composition comprising (a) about 10 to 90% by weight of the pentane selected from the group consisting of one or more of n-pentane and i-pentane and (b) about 90 to 10% by weight of a halocarbon selected from the group consisting of 142b and 124.
2. 2. A foam blowing agent composition comprising (a) about 10 to 90% by weight of a pentane selected from the group consisting of one or more of pentane and i-pentane and (b) approximately 90 to 10% by weight of 142b.
3. 3. A foam blowing agent composition comprising (a) from about 10 to 90% by weight of a pentane selected from the group consisting of one or more of n-pentane and i-pentane and (b) about 90 to 10% by weight of 124.
4. 4. A foam blowing agent composition comprising (a) about 10 to 90% by weight of n-pentane and (b) about 90 to 10% by weight of a halocarbon selected from group consisting of 142b and 124.
5. 5. A foam blowing agent composition comprising (a) about 10 to 90% by weight of β-pentane and (b) about 90 to 10% by weight of a halocarbon selected from the group consisting of 142b and 124.
6. 6. A foam pre-mix composition comprising a polyol and the foam blowing agent composition of the claim 1 .
7. 7. A foam pre-mix composition comprising a polyol and the foam blowing agent composition of claim 2.
8. 8. A foam pre-mix composition comprising a polyol and the foam blowing agent composition of claim 3.
9. 9. A foam pre-mix composition comprising a polyol and the foam blowing agent composition of claim 4.
10. 10. A foam pre-mix composition comprising a polyol and the composition of foam blowing agent of claim 5.
11. 11. A polyurethane foam composition comprising an A side containing an isocyanate and a B side containing a polyol and the foam blowing agent composition of claim 1.
12. 12 The polyurethane foam composition of claim 11, wherein a portion of the pentane is contained on the A side.
13. 13. A polyurethane foam composition comprising an A side containing a polyurethane foam composition. socianato and a side B containing a polyol and the foam blowing agent composition of claim 2.
14. 14. The polyurethane foam composition of claim 13, wherein a portion of the pentane is contained on the A side.
15. 15. A polyurethane foam composition comprising an A side containing an isocyanate and a B side containing a polyol and the foam blowing agent composition of claim 3.
16. 16. The polyurethane foam composition of claim 15, wherein a portion of the pentane is contained on the A side.
17. 17. A polyurethane foam composition comprising a side A containing an isocyanate and a B side containing a polyol and the foam blowing agent composition of claim 4.
18. 18. The polyurethane foam composition of claim 17, wherein a portion of the pentane is contained in side A.
19. 19. A polyurethane foam composition comprising an A side containing an isocyanate and a B side containing a polyol and the foam blowing agent composition d e claim 5.
20. 20. The polyurethane foam composition of claim 19, wherein a portion of the pentane is contained on the A side.