Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2000-03-29
2003-01-07
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S054000, C524S270000, C524S274000, C524S457000, C524S764000, C524S773000, C524S798000, C526S090000, C526S216000, C526S238300, C526S307000, C526S319000, C526S320000, C106S311000
Reexamination Certificate
active
06503971
ABSTRACT:
FIELD OF INVENTION
This invention relates to novel rosin-fatty acid vinylic polymer compositions that exhibit characteristics which make them useful as grind resins for preparing grind vehicles for ink and coating formulations. In particular, this invention relates to rosin-fatty acid vinylic grind resin compositions produced from the addition polymerization reaction of a mixture of rosin and fatty acid and a mixture of (meth)acrylic and vinylic monomers.
BACKGROUND OF THE INVENTION
Impelled by environmental concerns and increasing governmental regulations on the volatile organic content of coatings, the applications of water-based inks are increasing in the ink industry. A typical water-based ink system is formulated by the addition of a pigment to a grind resin. These grind vehicles are prepared by using grinding resins to disperse pigments. Typically, such grind resins are cut into aqueous ammonia at a pH of about 8.5 and the resulting solutions are employed to grind the pigments. Pigments are crystalline solids composed of agglomerates, aggregates, and primary particles which vary in size from 0.02 to 0.50 microns. During the grinding process, agglomerates and aggregates are broken down into primary particles which possess strong tendencies to reassociate in an ink. The finer the particle size of the pigment, the greater the color strength, but the more difficult the pigment becomes to disperse. Grinding resins help prevent the particles from reassociating by increasing both the electrostatic and steric repulsion between pigment particles.
The traditional process for producing polymer resins is well known (see generally U.S. Pat. Nos. 4,839,413 and 5,216,064, which are hereby incorporated by reference). Commonly a solution polymerization reaction is employed wherein styrenic monomer and acrylic acid is mixed with a hydrocarbon solvent, a polymerization initiator, and a chain transfer agent. Upon completion of the reaction, the solution is stripped of the solvent to yield the acrylic polymer (which may subsequently be employed as a grind resin).
However, major problems exist with the traditional methods of producing such grind resins. For example, these methods require the use of environmentally adverse hydrocarbon solvents. Moreover, as these solvents are not usable or desirable in water-based ink formulations, the solvents must be stripped from the resulting acrylic polymers (thereby causing a yield loss). This stripping step also adds expense to the process due to both the loss of yield and the energy consumed in performing the stripping. Also, these methods must utilize chain transfer agents to regulate the molecular weight of the resulting grind resins.
Therefore, an object of this invention is to solve these major problems by disclosing rosin-fatty acid vinylic polymer grind resins.
Another object of this invention is to disclose a method of producing rosin-fatty acid vinylic polymer compositions which exhibit properties that make them useful as grind resins for formulating grind vehicles for inks and other coatings.
SUMMARY OF THE INVENTION
The objects of this invention are met by via a method that employs rosin and fatty acid to act as solvents in the polymerization reaction of the acrylic monomers, thereby producing rosin-fatty acid vinylic polymer compositions which exhibit properties that make them useful as grind resins in inks and other coating applications. As this method does not require the use of hydrocarbon solvents, the need for solvent stripping is eliminated. Also, the polymerization reaction can be conducted at higher temperatures (i.e., up to boiling point of fatty acid) than traditional solution polymer methods, thereby allowing the practitioner to utilize smaller amounts of free radical initiators. Furthermore, the practitioner is able to regulate molecular weight without the use of chain Bit transfer agents, thereby both reducing costs and avoiding the production of unpleasant odors associated with such agents. Moreover, the fatty acid and rosin can function as a reactive diluent to impart flexibility to the grind resins.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The rosin-fatty acid vinylic polymer grinding resin compositions comprise the addition polymerization reaction products of:
(A) about 20.0% to about 60.0% by total weight of the reactants of a fatty acid rosin mixture comprising:
(1) about 10.0% to about 90.0% by total weight of the fatty acid rosin mixture of fatty acid, and
(2) about 10.0% to about 90.0% by total weight of the fatty acid rosin mixture of rosin; and
(B) about 40.0% to about 80.0% by total weight of the reactants of a monomer mixture comprising:
(1) about 15.0% to about 45.0% by total weight of the monomer mixture of a member selected from the group consisting of acrylic acid, methacrylic acid, and combinations thereof,
(2) about 55.0% to about 85.0% by total weight of the monomer mixture of a member selected from the group consisting of vinylic monomers and combinations thereof,
(3) about 0.5% to about 5.0% by total weight of the monomer mixture of a polymerization initiator,
(4) up to about 4.0% by total weight of the monomer mixture of a chain transfer agent, and
(5) up to about 30.0% by total weight of the monomer mixture of a hydrocarbon solvent; at a temperature in the range of about 135° C. to about 175° C. to produce the rosin-fatty acid vinylic polymer grinding resin compositions having a weight average molecular weight in the range of about 4,000 to about 12,000.
Preferred rosin-fatty acid vinylic polymer grinding resin compositions comprise the addition polymerization reaction products of:
(A) about 20.0% to about 60.0% by total weight of the reactants of a fatty acid rosin mixture comprising:
(1) about 20.0% to about 50.0% by total weight of the fatty acid rosin mixture of fatty acid, and
(2) about 50.0% to about 80.0% by total weight of the fatty acid rosin mixture of rosin; and
(B) about 40.0% to about 80.0% by total weight of the reactants of a monomer mixture comprising:
(1) about 20.0% to about 25.0% by total weight of the monomer mixture of a member selected from the group consisting of acrylic acid, methacrylic acid, and combinations thereof,
(2) about 60.0% to about 70.0% by total weight of the monomer mixture of a member selected from the group consisting of vinylic monomers and combinations thereof,
(3) about 1.0% to about 3.0% by total weight of the monomer mixture of a polymerization initiator,
(4) about 0.5% to about 2.0% by total weight of the monomer mixture of a chain transfer agent, and
(5) about 1.0% to about 4.0% by total weight of the monomer mixture of a hydrocarbon solvent;
at a temperature in the range of about 135° C. to about 175° C. to produce the rosin-fatty acid vinylic polymer grinding resin compositions having a weight average molecular weight in the range of about 4,000 to about 12,000.
The addition polymerization reaction used to produce the rosin-fatty acid vinylic polymer grinding resin compositions is a melt polymerization reaction in which no water is employed. Reaction temperatures suitable for use in the present method are within the range of about 135° C. to about 175° C.; with the preferred temperatures being in the range of about 140° C. to about 170° C.
The rosin and fatty acid function as solvents in the polymerization reaction of the acrylic monomers. Additionally, while a portion of the fatty acid and the rosin component remains unreacted, some of the fatty acid and rosin becomes graft polymerized onto the acrylic. The resulting rosin-fatty acid vinylic polymer grinding resin compositions have a weight average molecular weight in the range of about 4,000 to about 12,000; with the preferred molecular weights being in the range of about 5,000 to about 11,000.
These rosin-fatty acid vinylic polymer compositions have characteristics which differ from the traditional melt blends of flake acrylic fatty acid rosin. For example, the low molecular weights of the rosin-fatty acid vinylic polymers enable the polymers to be neutralized at high solid levels while maintaining low v
Adams Stanley C.
Shah Rajnikant
Egwim K C
McDaniel Terry B.
Reece IV Daniel B.
Schmalz Richard L.
Westvaco Corporation
LandOfFree
Rosin-fatty acid vinylic polymers as grind resins and grind... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rosin-fatty acid vinylic polymers as grind resins and grind..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rosin-fatty acid vinylic polymers as grind resins and grind... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3021819