Application of Robert G. Woolery

405 F.2d 896, 56 C.C.P.A. 842

• Court: Court of Customs and Patent Appeals
• Decided: January 16, 1969
• Docket: Patent Appeal 8020
• Status: Published

Opinion

RICH, Judge.

This appeal is from the decision of the Patent Office Board of Appeals affirming the rejection of claims 1-18 of application serial No. 432,382, filed February 12, 1965, entitled “Cellulosic Paper Containing Asbestos.” No claim has been allowed.

The invention relates to the manufacture of paper comprising primarily cellulosic fiber and using in addition a material which appellant refers to as “high purity” asbestos and defines as “chrysotile asbestos characterized by a specific surface area greater than 60 m2/gm., a magnetite content less than 0.5 per cent, a reflectance greater than 72 per cent and a pulpability such that less than 1.0 %- of the asbestos is retained on a 65 mesh Tyler screen.” As discussed in more detail below, use of this “high purity” asbestos in the manufacture of cellulosic paper, as compared to the use of “prior art” asbestos or no asbestos at all, is said to result in a number of improvements in the quality of the paper and in the manufacturing process.

Claim 1 is representative of the claims on appeal:

1. A paper furnish composition suitable for the preparation of non-woven paper sheets comprising:

(a) an aqueous dispersion of cellulosic paper-making fibers, and

(b) from about 0.5 to 30 per cent by weight, based on the weight of the cellulosic fibers, of high purity chrysotile asbestos characterized by a specific surface area greater than 60 m2/gm., a magnetite content less than 0.5 per cent, a reflectance greater than 72 per cent, and a pulpability such that less than 1.0 per cent of the asbestos is retained on a 65 mesh Tyler screen.

Claims 6 and 14 are also independent claims drawn, respectively, to a process of manufacturing paper using the composition of claim 1 and a paper sheet obtained by this process. Claims 2-5, 7-10, and 15-18 are ultimately dependent on claims 1, 6, and 14, respectively, and recite “sizing,” a “rubbery latex binder,” or a “non-fibrous inorganic filler” as additional paper-making ingredients. Claims 11 and 12 are independent claims drawn to two preferred embodiments of the process wherein a pre-mixed, “high-purity” asbestos composition containing a dye (claim 11) or containing a non-fibrous inorganic filler (claim 12) is added to an otherwise conventional paper furnish composition prior to depositing the furnish on a paper-making screen. Claim 13 is dependent on claim 12 and recites a specific filler, titanium dioxide.

The only issue we find it necessary to consider is whether or not the claimed invention is obvious within the meaning of 35 U.S.C. § 103 in view of prior art and therefore unpatentable. Four United States patents were relied on by the examiner:

Greenman et al. 2,698,788 Jan. 4, 1955

Schur et al. 2,733,720 Feb. 7, 1956

Poelman et al. 3,034,981 May 15, 1962

Novak 3,062,701 Nov. 6, 1962

The examiner rejected all claims on Novak alone, certain claims were alternatively rejected on Schur alone, and several claims were further rejected on Novak in view of Poelman or Greenman. We need not discuss Schur because Novak is clearly the more relevant of the two primary references. Since Poelman and Greenman were cited solely to show the use of latex with asbestos fiber compositions, and since appellant, in his application and in his brief, admits that this use of latex was known in the art, it is also unnecessary for us to diseüss these two references or the rejections based on their combination with Novak.

The only remaining reference, Novak, discloses a method of opening the tight fiber bundles of milled chrysotile asbestos into unit fibers and discloses the use of these fibers as an additive in cellulosic paper. The milled asbestos is opened by agitation in water containing a controlled amount of a surface active agent. There is obtained a dispersion of unit fibers which, upon standing, reverts to a “minimal clotted” state. Novak states that “Such minimal clotted asbestos fiber body may then be readily diluted to any desired degree in the paper-making process and added at a point in the beater where the paper-making adjuvants, such as alum, sizing, and the like are introduced.” Novak asserts that this method of obtaining unit asbestos fibers is preferred to grinding and beating milled asbestos to very small bits, lengthwise and in diameter, because it provides longer fibers of more uniform diameter.

The examiner observed that Novak shows the combination of cellulosic fibers and unit asbestos fibers and took the position that it would be obvious to one skilled in the art to substitute other unit asbestos fibers for those used by Novak. The board affirmed the decision of the examiner stating, inter alia:

Since * * * Novak * * * disclose [s] the use of asbestos fibers in papermaking, it would have been obvious to a person of ordinary skill in this art to employ a subsequently discovered or developed improved form of asbestos fibers for the same purpose with the expectation of obtaining improved results.

With reference to a Rule 132 affidavit filed by appellant, the board said:

* * * it appears that the advantages urged are those which would be expected to flow from the substitution of a “high purity” asbestos for any of those previously employed.

Appellant acknowledges “that asbestos has long been used as an additive to cellulosic paper * * *.” 1 However, he says that attempts to use “prior art asbestos” 2 in the better grades of paper, such as white writing paper, have presented a number of problems such as lumping, coarseness, black specks, and gray coloration. The lumping and coarseness, appellant says, are caused by “flakes and bundles of unrefined or unopened asbestos fibers” which “not only give the paper an unsightly appearance, but * * * [give] it a rough uneven surface which causes uneven dye and ink receptivity.” This lumping and coarseness is said to prevent the use of prior art asbestos even in brown wrapping paper. With respect to the problems of black specks and gray coloration, resulting from the use of “prior art asbestos,” appellant’s specification states:

Prior art asbestos has not been used successfully in the manufacture of white paper, for several reasons, among them being its low (below 70%) reflectance level. * * *

* * * It is to a great extent the presence of magnetite particles that renders prior art asbestos grey rather than white, which is the color of highly purified asbestos. Magnetite occurs in most chrysotile asbestos deposits as a hard black crystalline material. Its presence is highly detrimental in a paper furnish, since it causes black specks to appear in the paper, lowers its reflectance, and due to its abrasiveness causes excessive wear on paper-making screens and printing plates. 3

Appellant has discovered that all these problems can be avoided by utilizing an asbestos having a higher reflectance, lower magnetite content, higher specific surface area, and lower pulpability than the “prior art” asbestos; the magnitude of the differences between “high purity” asbestos and “[two] types of the closest commercially available * * * chrysotile asbestos” (emphasis added) is shown in Table I, infra, from appellant’s specification.

Table I

COMPARATIVE PHYSICAL PROPERTIES OF ASBESTOS FIBERS

Type of Asbestos Per Cent Reflectance Per Cent Magnetite Specific Surface Area, m2/gm. Pulpability % +65 mesh

Canadian Chrysotile 55-70 3.5-4.8 19-31 10-20

Conventional Coalinga Chrysotile 60-64 1.0-3.0 55-59 10-67

High Purity Coalinga Chrysotile 72-78 0.04-0.5 60-80 0.25-1.0

The higher purity (higher reflectance and lower magnetite content 4 ) of “high purity” asbestos eliminates the problems of grayness and black specks; the small er particle size (higher specific surface area) eliminates coarseness; and the low incidence of unopened fiber bundles (low pulpability) eliminates lumping. Also, examples in appellant’s specification demonstrate that, compared to the use of no asbestos in the manufacture of paper, “high purity” asbestos improves retention of cellulosic fibers, fillers, and latex as water is eliminated from the paper furnish composition; the asbestos is said to “act like a filter” which catches the other ingredients and is also said to attract inorganic fillers such as titanium dioxide.

Appellant acknowledges that patent-ability of all of the appealed claims rests only on one ground, the use of “high purity” asbestos. The issue of non-obviousness may therefore be reduced to the following: would one of ordinary skill in the art, at the time appellant’s invention was made, have considered it obvious to use an asbestos having the characteristics of “high purity” asbestos in the manufacture of cellulosic paper with the expectation of obtaining improved results which appellant has shown to be possible. In view of the specific teachings of Novak referred to below, we are convinced that he would.

Regarding the desirability of using an asbestos which has a high surface area and is free of unopened fiber bundles, Novak says:

Surface area determinations have indicated that the area of a given weight of my unit asbestos fibers is at least five times that of milled asbestos fiber. Since the increase in the number of fibers is at least five times the increase in surface area as a bundle of fibers is opened to its unit fibers, there must be at least 25 times as many fibers in a given weight of my fibers as in milled fiber. This is responsible for the much greater smoothness, softness, and uniformity of asbestos papers made from these opened fibers. This also accounts for the much greater efficiency of these fibers in separating cellulose fibers from each other when used with cellulose fibers in cellulose paper making.

The softness and inertness of asbestos fiber has been desired as a modifier of the relatively harsher cellulose fibers, but combinations have been unsatisfactory because of the same coarseness and ununiform fiber character that exists in commercial asbestos paper. Bits of unopened asbestos fiber that might be tolerated in the latter, would be fatal to the expected uniformity of cellulose papers. * * * my opened fiber in slurry form is as smooth and uniform as a well-made cellulose paper making slurry, and can therefore be used therewith in any desired proportion to provide its characteristic properties to the composite of fibers. [Emphasis added.]

Regarding “cleanliness and fineness,” Novak also teaches that “undesirable oversize or foreign particle material content” should be removed from the unit asbestos fibers by “screening, straining, centrifuging, etc.,” the colloidal suspension. Novak further discloses that unit asbestos fibers aid in the retention of “powdered materials such as pigments, fillers, resins or other modifying agents” because of entanglement of the latter in the former, and further discloses that titanium dioxide particles are strongly attracted to unit asbestos fibers when the two materials are in a dispersion.

Comparing the differences between appellant’s “high purity” asbestos and the “prior art” asbestos (other than Novak’s, note 2 supra) we thus find the desirability of each difference taught in Novak, namely, low foreign material particle content (high reflectance and low magnetite content), high surface area, and relative absence of unopened fiber bundles (low pulpability). We also find teachings that unit asbestos fibers aid in the retention of other paper making ingredients by way of entanglement and even find a teaching that unit asbestos fibers attract titanium dioxide particles.

Appellant maintains that Novak does not render obvious the use of “high purity” asbestos because suspensions of unit asbestos fibers produced by the Novak process contain a surface active agent and because the final product of the Novak process is in a minimal clotted state. These arguments, however, are not well taken since both of the differences referred to relate only to the Novak process and product and do not in any way detract from the teachings of the importance of using, in cellulose paper making, an asbestos in the unit fiber state, free of unopened fiber bundles, and free of foreign particles. In short, we think that one skilled in the art having used a “prior art” asbestos in the manufacture of, for example, white writing paper and having obtained a coarse, lumpy, black-speck-containing, gray product, would be led by the Novak teachings to use a cleaner, finer asbestos free of oversize particles and black-speek-causing materials. To us it appears that appellant has at best found that an asbestos of optimum cleanliness, fineness, and uniformity will give the expected results. We appreciate that production of such an asbestos on a commercial scale might be very difficult indeed; but that fact does not render non-obvious the use of that asbestos in paper making. 5

Appellant’s Rule 132 affidavit at first glance appears to show that use of appellant’s “high purity” asbestos in the manufacture of paper gives results superior to those obtained using asbestos prepared according to the Novak process; 6 upon closer scrutiny, however, we find a number of serious defects which render this affidavit totally unpersuasive. The most serious of these defects, and the only one we need discuss, is that the asbestos compared with appellant’s “high purity” asbestos was prepared in a manner contrary to Novak’s teachings. Whereas Novak makes it abundantly clear that the amount of surface active agent used in his process should be just sufficient to result in the formation of an unstable colloidal dispersion of asbestos fibers which will revert to a “minimal clotted” state, appellant’s affidavit expressly refers to the use of an amount of surface active agent sufficient “to obtain a stable dispersion.” (Emphasis added.) 7 Furthermore, although Novak teaches that

Bits of unopened asbestos fiber that might be tolerated in * * * [asbestos paper], would be fatal to the expected uniformity of cellulose papers * * *

and that

During the evanescent colloidal periods it was possible to clean the fibers by screening, straining, centrifuging, etc., to remove undesirable oversize or foreign particle material content, and then allow the slurry to break [revert to the “minimal clotted” state] on further standing or mixing * * * [emphasis added]

appellant omitted this cleaning step. It is therefore no wonder to us that the paper produced from the Novak asbestos (as prepared by appellant) was coarse and ununiform and contained dark specks and asbestos fiber agglomerates.

The decision of the board is affirmed.

Affirmed.

WORLEY, C. J., took no part in the decision of this ease. SMITH, J., participated in the hearing of this case but died before a decision was reached.

1 . The following definition appears in appellant’s application:

The term “paper” is used throughout the specification and claims of this disclosure in its generic sense to include any non-woven, felted fibrous sheet, including but not restricted to bond, wrapping, tissue, printing, -wall and backing paper, as well as cardboard, wallboard, millboard, and the like.

2 . This expression, as used by appellant and as used herein, refers to “commercially available” asbestos such as that compared with appellant’s “high purity” asbestos in Table I, infra, and does not include asbestos obtained by the Novak process.

3 . It is pertinent to point out that appellant does not assert that the art failed to recognize these causes of lumping, coarseness, black specks, and grayness.

4 . Appellant’s brief states :

Perhaps the Board was misled by the term “high purity” asbestos and assumed from this convenient lable [sic] that appellant’s asbestos product was simply more pure than “prior art” asbestos. Reference to the specific, critical and unique characteristics or limitations will show that only one of the four limitations is related to purity, namely magnatite [sic] content. The other three limitations, surface area, reflectance, and pulpability have no direct relationship to purity. [Einphasis quoted.]

Appellant's specification, however, belies these assertions, viz. :

The significantly greater purity of the asbestos essential in this invention is demonstrated by its improved reflectance and magnetite content. [Emphasis added.]

5 . Appellant has not contended that one skilled in the art -would have difficulty producing such an asbestos at least on a laboratory scale.

6 . Superior results, of course, are not necessarily unexpected.

7 . Novak discloses that, if a suspension of “minimal clotted” asbestos fibers is diluted with water, there results a “smooth slurry- of small, fluffy clots of fiber,” whereas, if a colloidal dispersion of asbestos fibers is diluted with water, the fibers form “strings or clots of jellylike character.” Such dilution occurs when the suspension or dispersion of asbestos fibers is added to aqueous suspensions of other paper-making ingredients.