Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Organic compound containing
Reexamination Certificate
2001-11-09
2004-07-06
Cooney, Jr., John M. (Department: 1711)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Organic compound containing
C521S129000, C521S137000, C521S163000, C521S170000, C521S174000, C528S049000, C528S053000
Reexamination Certificate
active
06759363
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to activators having reduced volatility that are liquid at room temperature, which activators make it possible to produce polyurethane foams having improved emission behavior.
In the production of cellular or compact polyurethanes, organometallic compounds and tertiary amines are primarily used as catalysts. A disadvantage of tertiary amines is their volatility. Various methods for reducing the volatility of tertiary amines have been proposed. When higher molecular weight compounds are used, the price paid for lower volatility is lower activity, which must be compensated for by the addition of an increased amount of catalyst.
EP-A 176 013 teaches use of aminoalkylureas as activators. These compounds already have reduced volatility and cause less contact discoloration of covering and lining materials adjacent to the polyurethane. However, their production requires long reaction times and their emission behavior does not yet meet the high demands of the automotive industry.
DE-OS 30 27 796 describes dialkylaminoalkylureas as activators for the production of polyurethane foams. These activators are prepared by reaction of secondary amines with diisocyanates in organic solvents and are obtained, after concentration, in the form of highly viscous to crystalline products. They must then be converted into a form suitable for use in the production of polyurethanes, since they cannot readily be processed in the form of the pure product. Such a conversion is complex and expensive.
SUMMARY OF THE INVENTION
It has now been found that particular urea derivatives and urethane derivatives, which can be obtained by reaction of specific amines with higher-functional polyisocyanates and isocyanate-reactive compounds, possess excellent solubility properties and exhibit low volatility and high activity in polyurethane foam-forming systems. Use of these activators results in extremely low emissions, even when subjected to heat, and does not damage other materials adjacent to the polyurethane. These advantages are important in connection with the problem of fogging (i.e., emissions in the interior of a motor vehicle), especially under the effect of heat, which can impair adjacent materials and can be detected in the air inside the motor vehicle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
The present invention relates to an activator useful for the production of polyurethane foams and to a process for the production of polyurethane foams in which this activator is employed. The activator of the present invention is a reaction product of
A) a secondary amine or primary alcohol having at least one tertiary amino group,
B) a polyisocyanate of the diphenylmethane series having a functionality of from 2.5 to 4.0, preferably from 2.5 to 3.5, and
C) an OH-functional reactive component capable of addition to isocyanate, preferably having a number-average molecular weight of from 62 to 750.
The reaction is preferably carried out with stoichiometric amounts of isocyanate B) and the secondary amine or primary alcohol having at least one tertiary amino group A). That is, one amino group or hydroxyl group of the secondary amine or primary alcohol having at least one tertiary amino group A) is present in the reaction mixture for each NCO group of the isocyanate B). The activator-forming reaction is preferably carried out in a manner such that the solvent component C) and component A) are placed in a vessel and the isocyanate B) is added at a temperature of from 20 to 50° C. When the addition of the isocyanate B) is complete, the reaction is carried out until no free NCO groups are present in the reaction mixture. This reaction is generally carried out at temperatures of from 20 to 100° C., preferably at from 40 to 60° C., most preferably at approximately 50° C., because at these temperatures, the solvent C) reacts with the isocyanate B) to only a minor extent.
The polyurethane foams of the present invention are generally produced by reacting
a) a polyisocyanate or polyisocyanate prepolymer,
b) at least one component that is reactive towards isocyanate groups and has a functionality of from 2 to 6 and a number-average molecular weight of from 1000 to 15,000,
c) optionally, a chain-lengthening agent having a molecular weight of from 62 to 999,
d) an activator according to the present invention,
e) water,
f) optionally, liquid CO
2
or an organic blowing agent,
g) optionally, a stabilizer, and
h) optionally, further additives.
In a preferred embodiment of the invention, the polyurethane is bonded to or manufactured with another material. For example, the polyurethane may be coated with a film or the polyurethane may be produced by applying foam-forming mixture to the back of a film or by spraying the back of a film with the polyurethane-forming mixture.
Other materials to which the polyurethane may be applied or with which the polyurethane may be manufactured preferably include PVC, ABS, mixtures of PVC, ABS, polyvinyl acetate, polyvinylbutyral, homo- or co-polymers based on vinyl chloride, styrene, butadiene, isoprene, chloroprene, dichlorobutadiene, ethylene, propene and acrylonitrile in the form of films, coatings and edgings of various colors, lacquers based on cellulose esters, polyester resins, epoxy resins, alkyd resins, as well as oil lacquers or lacquers of a combination of these components, and textiles based on cotton or leather. In a particularly preferred embodiment, polyolefins are used as the material with which the polyurethane is manufactured.
Suitable isocyanates useful for producing polyurethanes in accordance with the present invention include organic diisocyanates, polyisocyanates and polyisocyanate prepolymers. Suitable diisocyanates and polyisocyanates include aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, such as those described in Justus Liebigs
Annalen der Chemie
Volume 562, page 75 (1949). Examples of such isocyanates are those represented by the formula
Q(NCO)
n
in which
n represents an integer from 2 to 4, preferably 2, and
Q represents an aliphatic hydrocarbon radical having from 2 to 18 (preferably from 6 to 10) carbon atoms, a cycloaliphatic hydrocarbon radical having from 4 to 15 (preferably from 5 to 10) carbon atoms, an aromatic hydrocarbon radical having from 6 to 15 (preferably from 6 to 13) carbon atoms, or an araliphatic hydrocarbon radical having from 8 to 15 (preferably from 8 to 13) carbon atoms.
Polyisocyanates such as those described in DE-OS 28 32 253 are preferred. It is particularly preferred to use readily available polyisocyanates such as 2,4- and 2,6-toluene diisocyanate as well as any desired mixtures of those isomers (“TDI”), polyphenyl-polymethylene polyisocyanates, such as those prepared by aniline-formaldehyde condensation and subsequent phosgenation (“crude MDI”), and polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups (“modified polyisocyanates”), especially those modified polyisocyanates which are derived from 2,4- and/or 2,6-toluene diisocyanate or from 4,4′-and/or 2,4′-diphenylmethane diisocyanate. It is also possible to use prepolymers of these isocyanates and organic compounds having at least one hydroxyl group. Examples of suitable hydroxyl group-containing compound are polyols or polyesters having from one to four hydroxyl groups and number-average molecular weights of from 60 to 1400.
Polyisocyanates that are available under the name “polymeric diphenylmethane diisocyanate” and have a functionality greater than 2.0, mixtures thereof with diphenylmethane diisocyanate or ternary mixtures of polymeric diphenylmethane diisocyanate, diphenylmethane diisocyanate and toluene diisocyanate, as well as prepolymers prepared from the mentioned isocyanates are most preferred.
The isocyanate-reactive component contains at least one component that is reactive towards isocyanate groups and generally has a functionality of from 2 to 6 and a number-average m
Grammes Hartwig
Haas Peter
Wegener Dirk
Bayer Aktiengesellschaft
Cooney Jr. John M.
Gil Joseph C.
Whalen Lyndanne M.
LandOfFree
Activators for the production of polyurethane foams does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Activators for the production of polyurethane foams, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Activators for the production of polyurethane foams will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3204061