Chemical grafting onto a substrate and coating composition

Details Chemical grafting onto a substrate and coating composition Chemical grafting onto a substrate and coating composition

1999-12-07

2002-07-02

Berman, Susan W. (Department: 1711)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Compositions to be polymerized by wave energy wherein said...

C522S084000, C522S085000, C524S845000, C524S846000

Reexamination Certificate

active

06414048

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to coatings on a substrate, and, more specifically, to coatings that do not delaminate from the substrate and to coatings that are capable of receiving indicia.
2. Description of the Related Art
It is generally known in the art that the surface properties of shaped articles such as polymeric films and fibers can be modified by graft polymerization processes wherein the article is treated with a free radical generating agent such as an organic peroxide or high energy radiation and then contacted with an ethylenically unsaturated monomeric material under conditions wherein the monomer or graft polymer chain is caused to be covalently bonded to the substrate.
One particular process involves the treatment of natural or synthetic polymer substrates containing active hydrogen with an aqueous solution containing a silver salt (silver nitrate), a free radical polymerization catalyst and a free radically polymerizable monomer. The silver salt acts upon the substrate to remove active hydrogen thereby creating active sites or free radicals along the molecular chain and initiating and propagating polymerization of the monomer in conjunction with the free radical polymerization catalyst. The resulting product is a graft copolymer comprising a substrate having a plurality of polymeric side chains covalently bonded thereto. Examples of such processes are disclosed in U.S. Pat. Nos. 3,401,049 and 3,698,931, which are incorporated herein by reference in their entireties. This process is similar to grafting processes disclosed in U.S. Pat. Nos. 5,342,659; 5,439,969; 5,552,472; and 5,741,548, which are incorporated herein by reference in their entireties.
Organic solvent-based coating compositions are known in the art based on compositions curable by condensation reactions and containing polymeric material such as hydroxy terminated polyesters, diesters, acrylics and alkyds and an amino or polyisocyanate crosslinking agent. These formulations are adapted to be applied to a substrate such as metal, heated to drive off the solvent and further heated at temperatures above 80 degrees C. to activate the crosslinking mechanism.
It is known in the prior art that it is difficult to bond ink to certain substrates such as wood-based products and plastics, and even more specifically to polyolefin. The prior art discloses that the substrates may be precoated with a material to which the ink bonds. However, the prior art also discloses that the coatings may delaminate or be otherwise removed from the substrate. This is especially true for plastic substrates that are flexible or heat shrinkable, such as polyolefin tubing.
It is known in the prior art that a substrate may be treated to grow a polymer coating using a process known as chemical grafting. The resulting coating is covalently bonded to the substrate that is resistant to delamination. Chemical grafting involves the activation of the substrate. Once the substrate has been activated, chains of monomers linked by carbon-carbon bonds grow on the substrate as whiskers. These whiskers impart new and desirable properties to the substrate without damaging any of the existing positive characteristics of the substrate.
The chemical grafting processes relies on the fact that many materials; both naturally occurring and synthetic, possess hydrogens which are more active than the “bulk hydrogens.” Examples of relatively more active hydrogens include the tertiary hydrogen in polypropylene, the amide hydrogen in proteins, and the hydroxyl hydrogen in polysaccharide.
The chemical grafting process utilizes graft initiators (GI) that have the capacity of removing the active hydrogens and initiating the growth of polymer chains at the site of the removed hydrogen. In the case of polypropylene, the series of reactions is represented as follows:
A •represents a free radical, anion or cation, depending on whether the GI removes a hydrogen and one electron, no electrons, or two electrons. The below structure:
represents a unit of vinyl monomer where X governs the property or properties that are obtained with the resulting polymers attached and grown on the substrate. The graft polymer chains are formed from vinyl monomers or monomers containing appropriate functionability, e.g. groups such as hydroxyl, carboxyl, epoxy, amide, amine anhydride. In many instances a mixture of monomers is employed and often more than one property can be altered in one processing step. The polymers, whose length can be controlled, are permanently attached to the substrate. The linkage is between the grafted polymer and the substrate is covalent and cannot be leached or otherwise removed from the substrate absent mechanical means such as abrasion.
SUMMARY OF THE INVENTION
In an aspect of the invention, a composition provides a chemically grafted coating onto a substrate, wherein the composition comprises an acrylate and a grafting initiator. In further aspects of the invention, the acrylate is a waterborne urethane acrylate.
In further aspects of the invention, the composition comprises resistance agent, an adhesion agent, a UV curing photoinitator, a defoaming agent, and/or a deglossing agent. The resistance agent increases the chemical or mechanical resistance of the coating. In still further aspects of the invention, the resistance agent is an acryl-alkyd emulsion, a polyether, or a polyethylene glycol diacrylate. In other aspects of the invention, the adhesion agent is a polyethylene glycol diacrylate or an ethoxylated trimethylol propane triacrylate monomer. In additional aspects of the invention, the UV curing photoinitiator is 2-hydroxy-2-methyl-1phenyl-propane-1-one.
In an aspect of the invention, the composition comprises VIAKTIN VTE 6155W/50WA at 20-30 parts per weight; RESYDROL VAY 6278W/45WA at 4-5 parts per weight; RESYDROL AY 586 W/28 WA at 5-7 parts per weight; BYK 024 at 0.1-0.2 parts per weight,; FUJI 370 at 1.5-3.0 parts per weight; SR 344 at 0.12-0.20 parts per weight; de-ionized water at 4-50 parts per weight; ferrous ammonium sulfate (0.1% in de-ionized water) at 0.10-0.15 parts per weight; and DARACUR 1173 at 1.2-1.8 parts per weight.
In an aspect of the invention, the composition comprises VIAKTIN VTE 6155W/50WA at approximately 28.95 parts per weight; RESYDROL VAY 6278W/45WA at approximately 4.45 parts per weight; RESYDROL AY 586 W/28 WA at approximately 5.00 parts per weight; BYK 024 at approximately 0.10 parts per weight; FUJI 370 at approximately 1.8 parts per weight; SR 344 at approximately 0.16 parts per weight; de-ionized water at approximately 46.00 parts per weight; ferrous ammonium sulfate (0.1% in de-ionized water) at approximately 0.10 parts per weight; and DARACUR 1173 at approximately 1.55 parts per weight.
In an aspect of the invention, the composition comprises VIAKTIN VTE 6155W/50WA at approximately 28.95 parts per weight; RESYDROL VAY 6278W/45WA at approximately 4.45 parts per weight; RESYDROL AY 586 W/28 WA at approximately 5.00 parts per weight; BYK 024 at approximately 0.10 parts per weight; FUJI 370 at approximately 1.40 parts per weight; SR9035 at approximately 0.20 parts per weight; de-ionized water at approximately 46.00 parts per weight; ferrous ammonium sulfate (0.1% in de-ionized water) at approximately 0.10 parts per weight; and DARACUR 1173 at approximately 1.55 parts per weight.
In an aspect of the invention, the substrate is plastic or wood. In a still further aspect of the invention, the substrate is polyolefin.
In an aspect of the invention, a process for chemically grafting a coating onto a substrate comprising the step of providing a composition comprising an urethane acrylate and a grafting initiator along with the step of coating the substrate with the composition and curing the composition coated on the substrate. Further aspects of the invention include a product made by the process and that the substrate is plastic or wood, such as polyolefin for example.
In a further aspect of the invention, the curing step further comprises curing the composition

Affiliated with

Also associated with

Rating

Chemical grafting onto a substrate and coating composition does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Chemical grafting onto a substrate and coating composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chemical grafting onto a substrate and coating composition will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2847628