US PATENT CLASS 528
Class Notes


Current as of: June, 1999
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528 /   HD   SYNTHETIC RESINS OR NATURAL RUBBERS -- PART OF THE CLASS 520 SERIES



DEFINITION

Classification: 528/

Class 528 provides for all processes of preparing polymers from reactants wherein at least one reactant is devoid of ethylenic unsaturation. In addition, Class 528 provides for processes of removing contaminates or undesirable materials from a polymer, for processes of physically treating polymer-material, or for processes of chemically modifying a polymer without the addition of any extraneous material.

LINES WITH OTHER CLASSES

Listed below are rules to be followed in (1) placing patents into Class 528 and in (2) determining the appropriate subclasses to be searched in Class 528.

A. Classification in Class 528, subclasses 1-425 is on the basis of the reactants utilized. Some general rules to be followed in determining such reactants are as follows:

Process claim recites preparing an intermediate which is then reacted in a further step in preparing an additional intermediate

A + BC (Intermediate)

C (Intermediate) + D solid final product.

In this case, the reactants are A, B, and D. If reactant D is first appearing in the schedule array, there is no necessary cross-referencing to A, B, or to the intermediate C; however, if A or B is first appearing then a cross-reference should be placed in the subclass providing for C. B. Process claim starts with intermediate C (i.e., no positive preparation step claimed for intermediate C). Reaction calls for C (Intermediate) + D solid final product. In this case, reactants are C and D and classification is on the basis of the first reactant appearing in the schedule array. See (M) for classification of an intermediate condensation product.

C. Patentee claims polymer C. Examiner or searcher must look to the disclosure to see reactants utilized.

D. A liquid polymer which is exposed to an after treatment step is classified as a reactant.

E. When the claims and disclosures are silent as to whether the polymer treated is a liquid or solid, the polymeric material is to be regarded as a liquid and therefore as a reactant.

F. When the claims are silent as to whether the polymer prepared is a solid or liquid and the disclosure is alternative, disclosing both solid and liquid materials, original classification is on the basis of general rules of schedule hierarchy and the alternative species is mandatorily cross-referenced.

G. When the claims are drawn to alternative claimed subject matter involving solid and liquid polymers, original classification is appropriate on the basis of general rules of schedule hierarchy and the alternative species is mandatorily cross-referenced.

H. Where there are generic claims presented (i.e., alternative)as well as species claims such species claims will generally control for classification purposes over the generic presented claims.

I. Markush claims of A or B are regarded as individual species and classification is appropriate on the basis of general rules of schedule hierarchy.

J. Claims which are drawn to an intermediate condensation product as a reactant wherein applicant alleges indefinite structure for the condensation product, are classified on the basis of the reactants utilized in preparing the intermediate condensation product.

Urea-formaldehyde, phenol-formaldehyde, and methylol melamine are considered as being indefinite materials and are classified as urea + formaldehyde, phenol + formaldehyde, and melamine + formaldehyde.

The reaction of a urea-formaldehyde condensation material + melamine product to yield product is C is classified on the basis of either urea, formaldehyde, or melamine, depending upon which is the first-appearing reactant provided in the schedule array. If, however, the intermediate condensation product is of such definiteness as to be definable by applicant as a chemical compound, e.g., ester, polyester, polyether, polyamide, etc., such intermediate will be viewed as a compound and classified accordingly. An example of the aforementioned concept is as follows: Applicant starts with a (C) polyester prepared by reacting A + B. (C)polyester + isocyanate (D)---polymer (E). Reactants are C and D and claim is cross-referenced to A and B if desired. If applicant identifies the final reactant product only in terms of the reactants necessary to produce such reactant product (e.g., urea-formaldehyde, etc.) classification is to be made on the basis of the reactants recited.

K. In all cases where doubt exists as to whether a material that is present during a reaction is a reactant or a nonreactant (i.e., specified material) such doubt has been resolved by looking at the material as if it were a reactant.

L. Applicants' statements as to functions of materials (e.g., catalyst, reactant, solvent, etc.) are to be taken literally and to be followed. An exception to the preceding rule is in those subclasses where specified rules are enumerated. If the Examiner has any doubts as to statements of functions, such doubts can be resolved by adequate cross- referencing. A specific exception to the rule enumerated above regarding applicants' statements is the question as to whether a material is a solid resin for the particular chemical modification subclasses which are provided in the schedule. In those cases where the claims are silent, the Examiner may resolve the question by looking at the total disclosure of the patent.

M. Classification into subclasses 1-425 is primarily on the basis of reactant utilized. It is possible, however, that polymeric products which may be identical in structure may be prepared from different reactants, and that these reactant may not be claimed or disclosed in the patent being classified. In those instances where a product is claimed which the Examiner believes may be formed from reactants which are not disclosed in the patent at hand, an optional cross-reference into the nonclaimed or disclosed reactant area may be highly desirable and appropriate.

The following rules apply in classifying a claim into Class 528 in those subclasses of the schedule which provide for processes (i.e., in specified material areas).

A. Patents that claim a product and process, wherein both the product and the process are specifically provided for in the schedule, are classified in the process area and cross-referenced to the product area.

B. Patents that claim both a provided for product and a process of polymerizing, and wherein the product is claimed in process terms, are classified on the basis of the process and cross-referenced to the first-appearing reactant in the schedule utilized in preparing the polymer.

C. Patents that claim a product solely in process terms are classified on the basis of the process, when said process is provided in the schedule and cross-referenced to the first-appearing reactant in the schedule utilized in preparing the polymer.

D. Patents that claim a product in process terms, and wherein the process is not provided, are classified on the basis of the first-appearing reactant in the schedule utilized in preparing the polymer.

E. Patents that claim a polymerizable composition or the preparation of a polymerizable composition are classified on the basis of the first-appearing reactant in the schedule that is part of the polymerizable composition.

F. Patents that claim a polymer only are classified on the basis of the first-appearing reactant in the schedule that has been used in preparing the polymer. G. Patents that claim merely vulcanizing, curing, or cross-linking or a polymer proper for this area, without the presence of a specified vulcanizing, curing, or cross-linking agent, or the amount of the chemical agent or the vulcanized, cured, or cross-linked product of such a reaction are classified on the basis of the first-appearing reactant in the schedule that has been polymerized in the preparing the polymer.

H. Patents that claim a polymer which is the result of a degradation of a polymer proper for this area, and wherein the degradation has been effected in the absence of any chemical agent, are classified on the basis of the initial first-appearing reactant in the schedule that has been polymerized in preparing the previously formed polymer that is degraded.

I. This class provides for a composition of a polymer proper for this class admixed with a broadly claimed nonreactant not identifiable by a chemical atom or amount; or for a process of preparing a composition wherein the nonreactant material is not identified by a chemical atom or amount and wherein

the process of forming the composition recites no process condition other than mere polymerizing. (See Class 523, section I of the Class Definition, for a discussion of nonreactant materials and designated nonreactant materials.)

REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS

525, Synthetic Resins or Natural Rubbers,

242+, for products resulting from, or involving a polymer proper for this class reacted with an ethylenically unsaturated reactant.

GLOSSARY:

REACTANT

A reactant for purposes of this Class is a material which occurs in a polymer as a repeating unit and is present in at least three units. As used herein, reactant is meant to exclude catalyst residues, chain transfer agents, etc.

WITH For purposes of this class, the term "with" under a specific reactant subclass requires the presence of the specific reactant with a different reactant which meets the parameters set forth by the "with" definition.

CONTAINS

For purposes of this class, the term "contains" under a specific reactant subclass includes the term "with" and merely requires the presence of the "contains" material. The required moiety, element, etc., may be in the specific reactant or in an additional reactant.