Compositions: coating or plastic – Coating or plastic compositions – Molds and mold coating compositions
Reexamination Certificate
2000-12-29
2002-09-17
Gorr, Rachel (Department: 1711)
Compositions: coating or plastic
Coating or plastic compositions
Molds and mold coating compositions
C528S049000, C252S182200, C560S025000, C516S203000, C556S414000
Reexamination Certificate
active
06451101
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a parting agent for use with isocyanate wood binder resins and the processes of producing the parting agent. The parting agent can be used with isocyanate wood binder resins that can optionally include synergists such as C1 to C4 N-alkyl pyrrolidones or gamma-butyrolactone.
BACKGROUND OF THE INVENTION
A common disadvantage of the use of isocyanate binder resins is their poor mold or press release properties, which can lead to problems during manufacture of the lignocellulosic articles when the mold parts or press parts stick to the articles.
To overcome the sticking, it is desirable to use a parting agent either internally as a component of the binder resin, or externally by applying it to the mold or press parts between runs. External parting or release agents are less preferred because their use involves the extra step of applying the agents to the mold or press parts. Also it can be difficult to ensure complete coverage of the mold or press parts by the parting agent.
It is therefore, an object of the present invention to provide a parting agent for an isocyanate binder resin, which will not only display the desired parting properties but will also be compatible with the isocyanate binder resin.
SUMMARY OF THE INVENTION
There is provided according to a first embodiment of the present invention a parting agent, comprising the reaction product of an isocyanate compound and an isocyanate-reactive compound of the general structure
R-(ao)
n
-Y
wherein: R is a hydrophobic group containing alkyl, alkaryl, polyaryl, or siloxane moieties, wherein the alkyl moieties comprise straight chain or branched hydrocarbons with 6 or more carbon atoms, the alkaryl moieties comprise monoalkyl, dialkyl, or trialkyl substituted aromatic hydrocarbons with 9 or more carbon atoms, the polyaryl moieties comprise a polyphenyl structure that is either alkyl substituted or unsubstituted, and the siloxane moieties comprise a trisiloxane or higher polysiloxane; (ao) is an alkylene oxide or mixture of alkylene oxides selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide, and mixtures thereof; n is from 2 to 25; and Y represents a monofunctional isocyanate-reactive group.
In a second embodiment, a process for producing a parting agent comprises the step of providing an isocyanate compound and an isocyanate-reactive compound of the general structure R-(ao)
n
-Y wherein: R is a hydrophobic group containing alkyl, alkaryl, polyaryl, or siloxane moieties and wherein the alkyl moieties comprise straight chain or branched hydrocarbons with 6 or more carbon atoms, the alkaryl moieties comprise monoalkyl, dialkyl, or trialkyl substituted aromatic hydrocarbons with 9 or more carbon atoms, the polyaryl moieties comprise a polyphenyl structure that is either alkyl substituted or unsubstituted, and the siloxane moieties comprise a trisiloxane or higher polysiloxan; (ao) is an alkylene oxide or mixture of alkylene oxides selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide, and mixtures thereof; n is from about 1 to about 25; and Y represents a monofunctional isocyanate-reactive group. A second step comprises reacting the isocyanate compound and the isocyanate reactive compound for a time sufficient to react out substantially all of the isocyanate groups.
In a third embodiment a process for producing a parting agent comprises the step of providing an isocyanate compound and an isocyanate-reactive compound of the general structure R(ao)
n
Y in stoichiometrically equivalent amounts, wherein: R is a hydrophobic group containing alkyl, alkaryl, polyaryl, or siloxane moieties and wherein the alkyl moieties comprise straight chain or branched hydrocarbons with 6 or more carbon atoms, the alkaryl moieties comprise monoalkyl, dialkyl, or trialkyl substituted aromatic hydrocarbons with 9 or more carbon atoms, the polyaryl moieties comprise a polyphenyl structure that is either alkyl substituted or unsubstituted, and the siloxane moieties comprise a trisiloxane or higher polysiloxane; (ao) is an alkylene oxide or mixture of alkylene oxides selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide, and mixtures thereof; n is from about 1 to about 25; and Y represents a monofulnctional isocyanate-reactive group. The subsequent steps comprise reacting the isocyanate compound and the isocyanate reactive-compound at a first temperature until the isocyanate number is at an intermediate level; thereafter, adding a second charge of an isocyanate compound; and reacting the second charge of isocyanate compound and the isocyanate reactive-compound at a second temperature higher than the first temperature for a time sufficient to react substantially all of the isocyanate groups,.
In a fourth embodiment a process for producing a parting agent comprises the step of providing an isocyanate compound and an isocyanate-reactive compound of general structure R(ao)
n
-Y wherein: R is a hydrophobic group containing alkyl, alkaryl, polyaryl, or siloxane moieties and wherein the alkyl moieties comprise straight chain or branched hydrocarbons with 6 or more carbon atoms, the alkaryl moieties comprise monoalkyl, dialkyl, or trialkyl substituted aromatic hydrocarbons with 9 or more carbon atoms, the polyaryl moieties comprise a polyphenyl structure that is either alkyl substituted or unsubstituted, and the siloxane moieties comprise a trisiloxane or higher polysiloxane; (ao) is an alkylene oxide or mixture of alkylene oxides selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide, and mixtures thereof; n is from about 1 to about 25; and Y represents a monofunctional isocyanate-reactive group in amounts such that the molar ratio of the isocyanate compound to R(ao)
n
-Y is greater than 1:1. Subsequent steps comprise reacting the two compounds at a first temperature until substantially all of the R(ao)
n
-Y has reacted; thereafter, reacting at a second temperature higher than the first temperature until substantially all of the excess isocyanate groups have reacted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
The present invention teaches a parting agent, which comprises the reaction production of an isocyanate compound and an isocyanate-reactive compound.
The isocyanate compounds useful in the present invention comprise the organic di- and polyisocyanates, modified isocyanates, isocyanate-terminated prepolymers, and mixtures of these isocyanates, all described below.
The isocyanate compound which may be used includes aliphatic, alicyclic and aromatic polyisocyanates characterized by containing two or more isocyanate groups. Such polyisocyanates include the diisocyanates and higher fimctionality isocyanates, particularly the aromatic polyisocyanates. Mixtures of polyisocyanates may also be used and include, crude mixtures of di- and higher functionality polyisocyanates produced by phosgenation of aniline-formaldehyde condensates or as prepared by the thermal decomposition of the corresponding carbamates dissolved in a suitable solvent, as described in U.S. Pat. No. 3,962,302 and U.S. Pat. No. 3,919,279, the disclosures of which are incorporated herein by reference, both known as crude diphenylmethane diisocyanate (MDI) or polymeric MDI.
The organic polyisocyanate may be an isocyanate-terminated prepolymer prepared by reacting, an excess of a polyisocyanate with a polyol which, on a polyisocyanate to polyol basis, may range from about 20:1 to 2:1. The polyols include, for example, polyethylene glycol, polypropylene glycol, diethylene glycol monobutyl ether, ethylene glycol monoethyl ether, triethylene glycol, etc., as well as glycols or polyglycols partially esterified with carboxylic acids including all polyester polyols, and all polyether polyalkylene polyols. Such polyols are well known in the art and will not be further described.
The isocyanate compound may also be modified isocyanates, such as, carbodiimides, allophanates, isocyanurates, and biurets.
Als
Lu Li-Mei
Mente Donald C.
Peters David D.
Schaefer Anthony G.
Wilson Joe C.
BASF Corporation
Borrego Fernando A.
Gorr Rachel
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