MOLD RELEASE AGENT

Abstract

A mold release composition is provided contains a minimum of three reactive moieties per molecule to provide for both mold adhesion and crosslink density. The composition is soluble in a VOC-free organic solvent or water, alone or with resort to an emulsifier. The composition can be used as a semi-permanent mold release in some embodiments.

Claims

1. A process of molding comprising: applying mold release composition to a mold surface for forming a coating on the mold surface, the composition comprising a polysiloxane having the formula of formula 1: ##STR00003## where y3 and x is 0, where a reactive moiety for the purposes of the present invention include those moieties that react on the mold surface to form bonds to other polymers of Formula (I), the mold surface, or both, where reactive moieties comprise one or more of R.sup.4, R.sup.5, R.sup.6, or R.sup.7 , where R.sup.4, R.sup.5, R.sup.6, or R.sup.7 are the same or different and each is independently one or more of reactive moieties of glycydoxy, C.sub.1-C.sub.8 alkoxy, C.sub.1-C.sub.8 alkoxy having a substituent, a halogen of fluorine or chlorine, a C.sub.1-C.sub.8 halo alkyl, a C.sub.0-C.sub.8 hydroxyl alkyl, a primary or secondary amine having each group being C.sub.0-C.sub.8, an isocyanate, an ureido, a C.sub.2-C.sub.8 ethylenically unsaturated group, a C.sub.2-C.sub.8 ethylenically unsaturated group having a substituent, an acrylic, allyl alcohol, a halide, a hydroxyl group, methylacryloxy, acryloxy, mercapto, vinyl, styryl, chloropropyl, and sulfido, or independently one or more of unreactive moieties C.sub.1-C.sub.8 or longer alkyl, either branched or unbranched; and where R.sup.1 R.sup.2, R.sup.3, R.sup.8, R.sup.9, and R.sup.10 can be the same or different and each independently is a saturated C.sub.1-C.sub.8 or greater alkyl, either linear or branched; curing said composition to form a mold release coating; and placing of a material into contact with said mold release coating to form an article; and removing the article from contact with said mold release coating.

2. The process of claim 1 wherein the mold surface is a bladder surface.

3. A process of molding comprising: applying a composition to the inside of a green tire, said composition comprising a polysiloxane having the formula of formula 1: ##STR00004## where y3 and x is 0, where a reactive moiety for the purposes of the present invention include those moieties that react on the mold surface to form bonds to other polymers of Formula (I), the mold surface, or both, where reactive moieties comprise one or more of R.sup.4, R.sup.5, R.sup.6, or R.sup.7 , where R.sup.4, R.sup.5, R.sup.6, or R.sup.7 are the same or different and each is independently one or more of reactive moieties of glycydoxy, C.sub.1-C.sub.8 alkoxy, C.sub.1-C.sub.8 alkoxy having a substituent, a halogen of fluorine or chlorine, a C.sub.1-C.sub.8 halo alkyl, a C.sub.0-C.sub.8 hydroxyl alkyl, a primary or secondary amine having each group being C.sub.0-C.sub.8, an isocyanate, an ureido, a C.sub.2-C.sub.8 ethylenically unsaturated group, a C.sub.2-C.sub.8 ethylenically unsaturated group having a substituent, an acrylic, allyl alcohol, a halide, a hydroxyl group, methylacryloxy, acryloxy, mercapto, vinyl, styryl, chloropropyl, and sulfido, or independently one or more of unreactive moieties C.sub.1-C.sub.8 or longer alkyl, either branched or unbranched; and where R.sup.1 R.sup.2, R.sup.3, R.sup.8, R.sup.9, and R.sup.10 can be the same or different and each independently is a saturated C.sub.1-C.sub.8 or greater alkyl, either linear or branched; curing said composition to form a mold release coating; and placing of a material into contact with said mold release coating to form an article; and removing the article from contact with said mold release coating to the inside of the green tire; drying said composition to form a mold release coating; placing the green tire in a mold and over a bladder; inflating the bladder to mold the tire, with the dried composition partially or fully transferring from the green tire to the bladder; and performing more than one molding cycle without reapplying the composition to the green tires or the bladder.

4. The process of claim 3 further comprising repeat said injecting of said material and said removing the article.

5. The process of claim 3 wherein the mold surface is a bladder surface.

6. The process of claim 3 wherein said composition further comprises a solvent.

7. The process of claim 6 wherein said solvent is VOC free.

8. The process of claim 6 wherein said solvent is water.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The following detailed description is merely exemplary in nature and is in no way intended to limit the scope of the invention, its application, or uses, which may vary. The invention is described with relation to the non-limiting definitions and terminology included herein. These definitions and terminology are not designed to function as a limitation on the scope or practice of the invention, but are presented for illustrative and descriptive purposes only.

[0020] In at least one embodiment, the composition has the formula of formula 1:

##STR00002##

[0021] where y3 and x is 0. A reactive moiety for the purposes of the present invention include those moieties that react on the mold surface or bladder surface to form bonds to other polymers of Formula (I), the mold surface, or both. Reactive moieties R.sup.4, R.sup.5, R.sup.6, & R.sup.7 operative herein can be the same or different, and each is independently, but not limited to, a glycydoxy, C.sub.1-C.sub.8 alkoxy, C.sub.1-C.sub.8 alkoxy having a substituent, a halogen of fluorine or chlorine, a C.sub.1-C.sub.8 haloalkyl, a primary or secondary amine where each group is C.sub.0-C.sub.8, an isocyanate, a ureido, a C.sub.2-C.sub.8 or greater linear hydrocarbon comprising at least one ethylenic unsaturation and having a substituent, an acrylic, an allyl alcohol, hydroxyl group, methylacryloxy, acryloxy, mercapto, vinyl, styryl, chlropropyl, and/or sulfido. A substituent for R.sup.4, R.sup.5, R.sup.6, or R.sup.7 may include fluorine in place of hydrogen, perfluorinated forms thereof, a sulfonyl, or other suitable substituents. In contrast, non-reactive moieties in a molecule of formula (I) illustratively include where R.sup.1 R.sup.2, R.sup.3, R.sup.8, R.sup.9, and R.sup.10 can be the same or different and each independently is a saturated C.sub.1-C.sub.8 or greater alkyl, either linear or branched. It is appreciated that R.sup.4, R.sup.5, R.sup.6, and R.sup.7 can also each independently be a saturated C.sub.1-C.sub.8 or greater alkyl, either linear or branched with the proviso that at least three reactive moieties are present in Formula (I) for R.sup.4, R.sup.5, R.sup.6, and R.sup.7 and further that any hydrogen present in the R groups is non-labile so as to preclude the outgassing of hydrogen.

[0022] Additionally, although an inventive mold release polymer can be made from two different co-monomers are shown, it is appreciated that there can be any number of co-monomers that can be used to make the polymer.

[0023] In at least one embodiment, a release agent is provided. The release agent includes at least one reactive, modified polysiloxane. In at least one embodiment, the release agent further includes at least one modified reactive siloxane, a modified non reactive siloxane, or a combination thereof. It is appreciated that an inventive mold release in some applications functions a semi-permanent mold release. Semi-permanent in the context of the present invention is intended to define coatings applied to a mold surface which provides for more than one release per application.

[0024] In at least one embodiment of the present invention, a water-based release agent includes an emulsifier or blend of emulsifiers. In at least one embodiment of the present invention, a water-based release agent additionally includes one or more of: a catalyst, a thickening agent, a wetting (or re-wetting agent), a filler, a pigmenting agent, an antimicrobial agent, or combinations thereof.

[0025] It is to be understood that in instances where a range of values are provided that the range is intended to encompass not only the end point values of the range but also intermediate values of the range as explicitly being included within the range and varying by the last significant figure of the range. By way of example, a recited range of from 1 to 4 is intended to include 1-2, 1-3, 2-4, 3-4, and 1-4.

[0026] As used herein, a C.sub.0 moiety denotes the moiety absent a carbon chain; by way of example, a hydroxyl C.sub.0 alkyl denotes a hydroxyl directly bonded to the remainder of the molecule.

[0027] The materials that are used in multiple molding cycle release agents are myriad in number and are apparent to those of ordinary skill in the art. With no intent of limitation and as stated previously, materials which can be utilized to produce release agents described herein include, oils, fatty acids, metal salts of fatty acids, waxes, silicon based polymers, silanes, fluoropolymeric polymers, glycols and a myriad of combinations of the above. It is appreciated that these conventional materials are readily used in conjunction with an inventive mold release agent as sequential or layers on a substrate or as a formulation therewith.

[0028] An inventive mold release must provide for both adherence of the release agent to the mold (via one or more adhesion mechanisms), and provide for non-adherence of the molding article to the mold release interface in order to function as a semi-permanent mold release agent.

[0029] Formulation requirements are varied and in general are based upon the mold composition, the aggressive nature of the molding medium (to solvate and/or abrade the mold release interface), the requirement (or lack thereof) for release ease and/or mechanical slip, which is often dictated by the geometry of the molded article.

[0030] In at least one embodiment, the inventive release agent contains one or more reactive, polymers which serve as both adhesion mechanisms to the mold substrate as well as a release mechanism for the molding medium according to Formula (I).

[0031] In at least one embodiment of the present invention, the reactive polymer does not contain reactive moieties at the terminal ends of the polymer. In at least one embodiment of the present invention, the reactive polymer contains at least three reactive moieties per molecule. In still another embodiment of the present invention, the reactive polymer does not contain reactive moieties at the terminal ends of the polymer and contains at least three reactive moieties per molecule. In some embodiments of the present invention, the polymer of formula (I) has 4, 5, 6, and up to 20 or more reactive moieties with the appreciation that a molecular weight per reactive moieties value is readily varied with a lower molecular weight per reactive moiety typically associated with a harder coating having better mold surface bonding properties, as compared to a higher molecular weight per reactive moiety. In some embodiments of the present invention, the polymer of formula (I) has pendant reactive moieties. In still other inventive embodiments, the polymer of formula (I) has all of said reactive moieties being like moieties; which for example are all glycidyl moieties. Without intending to be bound to a particular theory of operation, it is believed that pendant reactive moieties bond to the surface of the mold or bladder and within the semi-permanent mold release layer.

[0032] In at least one embodiment, the compositions or agents of this invention can also contain one or more release mechanisms, catalysts, fillers, pigments, wetting agents, re-wetting agents, other additives (with no intention of placing any limitation) such as gas scavengers, fluorescing agents. Water-based systems may contain any and all of the above and may also include emulsifiers and anti-microbial agents.

[0033] Formation of such novel reactive polymers can be performed utilizing a variety of polymerizing processes.

[0034] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the described embodiments in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments.