CA2135611A1

CA2135611A1 - Topcoated adhesive diaper tape and method

Info

Publication number: CA2135611A1
Application number: CA002135611A
Authority: CA
Inventors: Thomas L. Mclaughlin; Carol A. Caldwell
Original assignee: Individual
Current assignee: Avery Dennison Corp
Priority date: 1992-05-12
Filing date: 1993-04-14
Publication date: 1993-11-25
Also published as: AU4104393A; JPH07506866A; TW273567B; US20020151865A1; US6365793B1; EP0665736A4; US6793757B2; EP0665736A1; US20020147437A1; US6663932B2; WO1993022996A1

Abstract

A pressure-sensitive tape substrate (30) is coated with an adhesive (34), and the adhesive is then printed with an ink or the like (36) that acts as an adhesive-inhibiting masking or barrier along one or more continuous zones or lines. Tapes (41, 42) are formed in whole or in part by slitting along the continuous line or lines so defined. The technique is used to make transfer tapes, diaper fastener tabs, and other products.

Description

` ~135611 PCTIUs93/0356 5 03 R~r ~ ~'T!~ .~ PR t994 TOPCOATED ADHESIVE

2 This invention relates to pressure-sensitive adhesive 3 tapes, adhesive tabs formed therefrom, and methods for 4 manufacturing the same. In one aspect, the invention relates to improvements in transfer tapes and like products, and in 6 the manufacture of the same. In another aspect, the invention 7 relates to improvements in laminate web constructions of 8 diaper fastener-tab stock of the kind adapted to be supplied g to a diaper manufacturer and to be separated by the manufacturer into individual diaper-fastening tabs and applied 11 to individual diapers, usually two tabs to a diaper for infant 12 diapers and six tabs to a diaper for adult diapers. In this 13 aspect, the invention particularly relates to means forming 14 part of the diaper tabs and providing novel conveniently manipulated fingerlifts for the'tabs.

16 Prlor Art 17 It has been previously proposed to make articles from 18 pressure-sensitive adhesive tapes in which the layer of 19 pressure-sensitiva adhesive is partially covered with a printed pattern of ink.
21 In U.S. Patent No. 3,159,930 to Allen et al., a pressure-22 sensitive tape has a layer 5 printed on the adhesive face.
23 This layer combines adhesive masking and indicia functions, ~4 the indicia being in the form of negative images in the mask.
The masking layer masks most of the adhesive at the centers 26 of the document-containing articles which are to be cut from 27 the tape, but leaves the adhesive exposed at the edges of the 28 articles. The tape is combined with a release liner.
29 In U.S. Patent`No. 3,874,893 to Cherrin, which is similar to Allen et al., one or more layers of ink or "overprint 31 lacquer" or "a coating which through solvent or other action 32 causes the adhesive to lose most of its adhesive properties"

DED SHEET
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P~TIUS93/03 56 5 2 1 3 5 ~ 1~ p ~ ~ . , " ~ ? . ~ 9 9 1 are applied to the adhesive side of a tape using a 2 flexographic press. When two printed layers ar~ used, the 3 first consists of printed indicia and the second of a 4 background layer which is patterned to leave the adhesive exposed at the ed~es of document-containing articles which are 6 to be cut from the tape. The background layer functions to 7 mask the adhesive so as to render it non-adhesive at the 8 printed areas. In one embodiment, additional spaced patterns 9 56 (Figs. 12 and 13) are printed on the adhesive to function as corner lift tabs when the tape is cut into individual 11 articles. However, the great majority of the cutting of the 12 tape is done directly through the adhesive at unprinted areas 13 thereof, thereby leaving unprinted adhesive directly exposed 14 at the side edges of the tape.
In U.S. Patent No. 4,068,028 to Samonides, indicia are 16 printed on the adhesive layer of transparent pressure-17 sensitive labels. These indicia are visi~le but "buried" and 18 protected when the labels are applied to a mounting surface.
19 In a variant, the labels are opaque, and indicia are printed both on the adhesive layer and on the face side of the label.
21 When the label is mounted on the inner side of a glass window 22 or the like, the indicia on the adhesive side are visible from 23 the exterior side of the window and the indicia on the face 24 side are visible from the interior side.
In U.S. Patent No. 4,107,811 to Imsande, a tacky floor 26 mat consists of a stack of adhesive-coated sheets peelably 27 joined to each other. To provide lift tabs for the sheets, 28 "a thin coating of non-adhesive material 18 is print-29 deposited" (col. 3, line 61) in a pattern on, the adhesive-coated web material from which the sheets are to be cut. The 31 adhesive-coated web material with the patterned coating 18 32 thereon is then laminated to itself to form a multilayer web 33 (presumably with the pattern of non-adhesive material 18 34 maintained in register, layer to layer). The laminated material is then cut to sheet size in such manner that the 36 patterned non-adhesive material 18 ends up at the corners of ~McNDED SI~EET

PCT/US~ 3/03 56- 5 ~ ~; t ~
2135611 ~3?~Q,.,~ n~Tlr-~ 1 8 ~nn 1994 1 the stacked sheets. The non-adhesive material may be of a 2 different color than the sheets. -~
3 In U.S. Patents Nos. 4,671,003 and 4,787,158 to Vitol, 4 removable pressure-sensitive sign stock is backed with release -- - 5 liner which has been perforated at regular intervais, the ~ 6 perforations being in the form of round openings where the ¦~ .7 adhesive is exposed. Talc or other adhesive masking material 1 8 is applied to the adhesive at the areas of these openings, and ~ 9 the stock is then slit in both directions to form individual 1 10 signs of rectangular or other shape each having one or more ¦ 11 starting tabs at one, two or four corners. Circular labels 12 are also disclosed having wedge-shaped non-adhesive areas, but l 13 how the corresponding perforations in the liner relate to the ¦ 14 circular label shape, and how the circular labels are formed from the label stock is not apparent.
16 Various fingerlift arrangements specific to diaper tabs . 17 are also known in the prior art. One si~ple arrangement is 18 to provide an adhesive--free zone at the fingerlift edge, as 19 in U.S. Patent No. 3,833,456 to Reed et al. This fingerlift edge can be difficult to grasp; there is no clear indication 21 of the presence of a fingerlift, and the unsupported edges of 22 rolls from which such tabs are cut can be easily damaged.
23 Another fingerlift arrangement for a diaper tab is a 24 fold-over arrangement, as in U.S. Patent No. 3,893,460 to Xarami. If such folding-over is done during manufacture of 26 the diaper fastener stock, differences in thickness are 27 created across the width of the stock, causing distortions !28 when the stock is rolled up for storage and shipment. On the 29 other hand, if the folding-over is delayed only to be ¦30 attempted on the diaper line, the difficulty of performing ~31 that step as part of the fastener dispensing and application !32 proce~ure on the diaper line presents a risk of line stops and 33 delays in diaper production.
34 Another known fingerlift arrangement for a diaper tab is .35 a strip lamination, as in U.S. Patent No. 4,726,971 to Pape 36 et al. The laminated strip extends outwardly of the width of r 213~ 611 ?CT/US ~ ~ / 0 3 5 6- -5 T ~r . ~ t~

1 the diaper fastener stock, so that when the same is rolled and 2 transported, the laminated strip can be easily dama~ed. Also, 3 the strip creates local thickness variations in the roll.
4 Still another arrangement is a pull string, as in U.S.
Patent No. 4,005,71~ to Mesek. This too may cause thickness 6 variations~ and may be complicated to fabricate and 7 manipulate, particularly at high diaper line speeds.

8 Summarv of the invention 9 Like the first six prior-art references listed above, the present invention also involves the making of articles from 11 pressure-sensitive adhesive tapes in which the layer of 12 pressure-sensitive adhesive is partially covered with a 13 printed pattern of an adhesive barrier or ink. However, in 14 the present invention as it relates to transfer tapes, the printing is along a continuous zone or line, and the tape is 16 formed in whole or in part by slitting along that continuous 17 line through the tape substra';e, an adhesive coating, and the 18 printed barrier. In the present invention as it relates to 19 diaper tabs, an adhesive barrier or ink is used to form end fingerlifts for the tabs.
21 In one aspect, the present invention involves the concept 22 of utilizing such means to eliminate or minimize 23 complications, constraints and disadvantages involved in 24 pattern-coating substrates with pressure-sensitive adhesive in the manufacture of transfer tapes and other articles. In 26 particular, the invention minimizes or eliminates 27 complications, constraints and disadvantages involved in the 28 need to pattern-coat the adhesive as it is applied in order 29 to allow slitting at one or more intermediate locations across the width of the line to define a specific tape width or 31 widths, and in order to provide adhesive-free and therefore 32 "pick"-free roll edge 33 The invention overcomes the present inability to slit 34 rolls of premanufactured transfer tape stock to various widths .
t .~ti~.~ci\~D~ L~

- r'CT/US ~ .~ / 0 3 5 6 S
.....
2 l 3 5 611~n~? P~ 1 8 4PR 199~

1 on demand, and eliminates the corresponding need to 2 manufacture and inventory various widths of transfer tape 3 pending demand for one or the other specific width or widths.
4 The invention enables the manufacture of tape stock and tapes - 5 of substantially uniform thickness from one edge to the other, 6 with attendant advantages to the manufacturer and converter.

7 In another aspect, the invention provides for the 8 manufacture of diaper fastener-tab stock, and diaper fastening g tabs formed from such stock, in a manner compatible with current diaper manufacturing practice, providing improved 11 diaper tabs, and improved tabbed diapers, at l:ittle or no 12 increase in costs over the practices of the prior art.
13 In this respect, the present invention provides diaper 14 tab fasteners having fingerlifts (i.e., end tabs for the tab fasteners themselves) which are 'Ibuilt-in~'' which are easy and 16 convenient to use, which overcome the problems of the prior-¦ 17 art diaper tab fingerlifts listed above, and which offer new 18 advantages including the ability to economically provide 19 improved distinguishability of the fingerlifts from the remainder of the tabs, the ability to provide for the 21 absorption of finger oils or othPr contaminants, and the 22 ability to add fragrances to the tabs.
23 In respect of the manufacture of diaper fastener-tab 24 stock with "built-in" end tabs, the invention provides a variant or alternative to the design o~ diaper fastener-tab 26 with built-in end tab taught in U.S Patent Application Serial 27 No. 07/710,692, filed June 5, 1991, of common assignee.

28 Brief Description of the ~rawings 29 The features and advantages of the invention will be more fully understood from the following description of specific 31 examples, together with the drawings, in which:
32 FIG. 1 is a schematic isometric view illustrating certain 33 prior art coating and slitting practices.
34 FIGS. 2 and 3 are similar views illustrating coating and ~ .ENDED SHEET
i .

2135611 P~T/US93/0356 5 R~ 8 ~PR 1994 1 slitting practices according to the present invention.
2 FIG. 4 is a broken cross-sectional view taken along plane 3 4-4 in FIG. 2, and inverted 180 degrees.
4 FIG. 5 is a cross-sectional view of an individual tape slit from the stock of FIG. 4.
6 FI~. 6 is a view similar to FIG. 5, but showing two 7 adjacent layers of the tape of FIG. 5, with one layer 8 superposed on the other, and thus illustrating two layers of 9 the tape as they would appear in a cross-sectional view of a roll of the tape.
11 FIG. 7 is a cross-sectional view similar to FIG 5 and 12 showing tape stock for the manufacture of diaper tabs 13 according to the invention.
14 FIG. 8 is a view similar to FIG. 7 and showing additional tape stock used with the stock of FIG. 7.
16 FIG. 9 is a cross-sectional view of the tape stocks of 17 FIGS. 7 and 8 combined with each other. FIG. 9 may also be 18 interpreted as a side elevation view of an individual diaper 19 tab cut from the combined stock.
FIG. 10 shows an individual tab corresponding to the 21 construction of FIG. 9 applied around the edge of a diaper.
22 FIG. 11 shows the same tab deployed for fastening to 23 another part of the diaper.
24 FIG. 12 is a view similar to FIG. 9 and showing a different form of diaper tab embodying the invention.
26 FIG. 13 is a cross-sectional view s`imilar to FIG. 7 27 showing tape stock for the manufacture of another form of 28 diaper tabs according to the invention`.
29 FIG. 14 is a view similar to FIG. 1,3 and showing additional tape stock used with the stock of FIG. 13.
31 FIG. 15 is a cross-sectional view of the tape stocks of 32 FIGS. 13 and 14 combined with each other. FIG. 15 may also 33 be interpreted as a side elevation view of an individual 34 diaper tab cut from the combined stock.
FIG. 16 shows an individual tab corresponding to the 36 construction of FIG. 15 applied around the edge of a diaper.

Al\lENDED SHEE~
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- ; ` ` 2135611 ~T/US ~ ;3 / 0 3 S g ~ --7- Q~ r,~ 1 8 AP~ 1994 1 FIG. 17 shows the same tab deployed for fastening to 2 another part of the diaper.
.:
3 Detailed Description of the Drawin~s 4 The coating and slitting shown highly schematically in FIG. 1 illustrates prior practices in the manufacture of 6 transfer tape. A roll 10 may comprise a web of release liner 7 substrate 12 which is coated on both sides with rele~se 8 coatings (not shown) either in prior coating operations before 9 the forming of roll 10 or as initial coating and drying steps (not shown) following off-feed from roll 10.
11 At an adhesive-applyin~ station A, a patterned adhesive 12 coating 14 is applied to the substrate 12. The patterning 13 results in a well-known manner from the use of die deckeling 14 or the use of pattern bars (not shown) to prevent or minimize the application of adhesive along lines or zones 16 which are 16 free or relatively free of adhesive.
17 The stock with its patterned adhesive coating is then 18 slit by the slitters i8 into individual transfer tapes, and 19 self-wound to form rolls of specific widths, such as the three individual rolls 21-23 in the illustration. The slitting 21 occurs along the absolutely or relatively adhesive-free lines 22 or zones 16. Slitting may also be performed at the adhesive-23 free side edges if edge trimming is required, but slitting at 24 only the central locations is shown to simplify the illustration.
26 In accordance with well-known practice, the release 27 coating (not shown) on the adhesive-carrying side of the 28 substrate 12 is chosen to give a higher or harder release than ¦ 2g the release coating (not shown) on the opposite or exposed side of the substrate. When each tape is self-wound into roll 31 form, the adhesive associated with one turn of substrate 32 contacts the exposed side of the preceding turn of substrate 33 which bears the release coating which allows relative low or 34 easy release. ~he result is that when the roll is ~ ,.

` PCT/US9 3/03 56 5 2l35 6 l l-8o3 ~nr~J ~ 8 APR 19~4 1 subsequently unwound, the adhesive layer remains associated 2 with the same length of substrate on which it was ~oated even 3 though there is a release coating (the one of relatively 4 higher or harder release) between the adhesive and that same 5 length of su~strate.
6 The adhesive face of the tape then can be applied to 7 label facestock or to another object intended to be adhesively 8 mounted in its end use, and the adhesive 14 permanently 9 adheres thereto. The substrate 12 then functions as a release 10 liner protecting the adhesive 14 until the liner is removed 11 and the label or other object is adhered to its final - 12 mounting. This final removal of the liner utilizes the 13 relatively higher or more difficult release action of the 14 release coating on the adhesive-bearing side of the substrate 15 1~.

16 The prior-art procedures described above and illustrated 17 in FIG. 1 in highly schematic form require that the adhesive 18 coating be patterned as it is applied in accordance with the 19 specific tape width or widths desired. This means that 20 adhesive-coated transfer tape stock cannot be premanufactured i 21 and inventoried, to be slit to various widths on demand.
¦ ~ 22 Instead, all widths expected to be eventually sold must be 23 patterned at the time the adhesive is applied, and widths of 24 various sizes then held in inventory pending eventual sale.
25 Such inventory consists of tape stock that has at least been 26 patterned to width. Slitting to width may be performed in the 27 same pass as patterning, or may be delayed up until time of I 28 sale. Some widths may sell more slowly than expected, and ~ 29 others faster, presenting the necessity of maintaining 1 30 whatever inventory is "thrust on" the manufacturer by reason 31 of bad guesses as to demand for various widths. For example, 32 in the example illustrated in FIG. 1, the operation 33 illustrated may be carried out as a result of an order for 34 tape of the width of roll 21, an intermediate width.
~ 35 Relatively narrow tape roll 22 and relatively wide tape 4 36 roll 23 (or the patternings for such rolls when slitting is ., 2135611 ~T/US93/035~5 n~ r~ n~T /r~ 8 f~ ~Q 1994 1 performed at a later pass) result as byproducts, so to speak, 2 of the manufacture of tape roll 21 and are a product of the 3 manufacturer's best guess as to the market for tapes of 4 various sizes, and must be inventoried until tapes of those specific sizes are in fact ordered.
- 6 Another disadvantage of prior art practice is the fact 7 that it is rather complicated to reset a coating operation as 8 required by changes in tape widths to be cut. Each change 9 requires redeckeling a die or resetting a pattern bar.
The relatively or absolutely adhesive-free lines or zones 11 16 present another problem in that the thickness of the stock 12 is considerably less at these zones than on the portions of 13 the stock bearing the adhesive layer 12. Thus, the stock at 14 the edges of the rolls 21-23 is substantially thinner than at 1~ 15 the central portions of the rolls, so that the stock is firmly ; 16 wound on itself, layer-to-layer, only at the central portions 17 and not at the edges. The stock at the edge portions is 18 therefore subject to being readily deformed and damaged by 19 accidental contact with any solid object.
In one aspect of the invention, these complications, 21 constraints and disadvantages of prior-art practice may be 22 largely or wholly eliminated. Thus, in the manufacture of 23 transfer tape as illustrated in FIG. 2, a roll 30 may again 24 be provided comprising a web of release liner substrate 32 which again is coated on both sides with release coatings (not 26 shown in this view) either in prior coating operations before -- 27 the forming of roll 30 or as initial coating and drying steps 28 (not shown) following off-feed from roll 30.
29 However, at the adhesive-applying station A, a layer of adhesive 34 is applied to the substrate 32 continually across 31 the width of the substrate 32. The adhesive-coating step may 32 be performed in the absence of any patterning, as shown, or - 33 less preferably there ~ay be patterning at the side edges.
34 Following applica ion of the adhesive layer 34, adhesive-inhibiting masking 36 is applied at a printing station P. The 36 masking may be an ink applied with a flexographic printing /IENDEC SHEET
, ~135611 10 ?~TlUS33/0356 5 1 press or laser printer (not shown), whose positions across the 2 width of the adhesive coating 34 may be readily adjusted as 3 desired to thereby determine tape width. Preferably, the 4 masking is applied at the side edges, as shown, as well as at an int~rme~iate portion o~ portions of the web.
6 Following drying of the ink or masking, employing drying 7 means if required (not shown), the adhesive-coated stock is 8 then slit by the slitter 38. Slitting may also be performed 9 at the side edges if edge trimming is required, but slitting at only the central location is shown to simplify the 11 illustration. The slit stock is then self-wound to form the 12 individual transfer tape roll 41, and the reserve roll 44 of 13 adhesive-coated stock. The stock in the reserve roll 44 is 14 not "committed" to specific roll widths, such as the relatively narrow width of the roll 22 or to the relatively 16 wide width of the roll 23 as in the prior-art example of FIG.
17 1.
18 If, at a later time, an order is received for one of the 19 latter widths, or any other width less than that of the reserve roll 44, the reserve roll can be processed as 1 21 illustrated in FIG. 3. Thus, the adhesive-coated reserve roll ¦ ~ 22 44 is unwound and passed through a printing station P to 23 receive the adhesive-inhibiting masking 36a. The lateral 24 location of the print cylinders or jets (not shown) is readily adjusted to produce the masking at the desired location across 26 the width of the reserve roll 44, as opposed to the laborious ~ 2~ process of redeckeling a die or readjusting a pattern bar, jJ 28 Qither of which involves resetting the coating operation.
~ 29 Following drying of the masking, employi~g drying means 3~ 30 if required (not shown), the stock is then slit by the slitter 31 38a. Thus a roll 42 of narrow width is produced pursuant to 32 a specific order, and also a roll 43 which, if not sold, may 33 be inventoried for possible later sale at that width, or at 34 narrower widths after further slitting.
FIGS. 4 to 6 illustrate the novel tape stock an~ tape of 36 the invention in greater detail. FIG. 4 is a cross-sectional ~ i .
A!AENûED SH~ET

- - ~ ~ . .

`-`` 2135611 ~CT/US9 3 / 0 3 5 6 5 O? ~r~ nf'~'r'~ l 8 Lt~ 99 1 view, partly broken, taken on plane 4-4 of FIG. 2 and inverted 2 180 degrees. The easier or lower release coati~ng 33 and 3 higher or harder release coating 35 are shown. FIG. 5 is a 4 cross section of the slit individual tape which is self-wound into the roll 41. FIG. 6 shows two adjacent wraps or turns 6 of ths roll 41. While these figures are not to scale, they 7 do give a rough idea of the insignificant effect of the 8 printed adhesive-inhibiting masking 36 on the overall 9 thickness of the tape. As suggested in FIGS. 4-6, the tapes are substantially uniform in thickness from edge to edge.
11 Preferably, the thickness of the masking means is less than 12 1% of the combined thickness of the associated substrate and 13 substrate adhesive. Actual typical thicknesses which have been 14 used are, for example, (microns): substrate 120, adhesive layer 30, release coats ~each) 1, ink or masking 0.4.
16 As particularly suggested by FIG. 6, the edge portions 17 of the tape rolls are substantlally as tightly wound as the 18 center portions, with firm layer-to-layer support between the 19 various turns of the roll out to the very edges of the roll.
In sum, the thickness of the masking means is a small 21 percentage of the combined thickness of the associated 22 substrate and substrate adhesive, preferably less than 1%, the 23 tape or diaper fastener stock has a substantially uniform 24 edge-to-edge thickness, the stock may be tightly rolled, and the layer edges at both sides of rolls of the stock are 26 solidly supported by adjacent layer edges.
27 Converters of tapes and other products using the printed 28 adhesive masking of the present invention can handle the 29 adhesive tapes or stocks efficiently. The, rolls can be tightly wouna. There is little or no cutting differential 31 between masked and unmasked adhesive areas. The rolls unwind 32 in a uniform manner. The risk of edge damage (nicking) of the 33 rolls is reduced.
34 As described above, in the foregoing examples of the invention, the printing of the adhesive barrier is along a 36 continuous zone or line, and the tape is formed in whole or E~

21~`~G11 l2 PCT/US93/0356 ~
0~ E;J 1 8 APR 1994 1 in part by slitting along that continuous line through the ~ tape substrate, an adhesive coating, and the prin~ed barrier.
3 Various adhesives have been used in transfer coating in 4 the past as illustrated in FIG. 1, and in general any such adhesive san be ~dapted to the invention. For ex~mple, t~e 6 adhesive may be a thermally cross-linked acrylic adhesive, the 7 cross-linking mechanism comprising a metal chelate such as 8 aluminum acetylacetonate ~in a small weight percentage, say 9 0.15%)-A suitable masking for such adhesive may be formed by I 11 printing, using as the ink "FLEXO WRITE ON WHITE" CLA 40457F
¦ 12 ink supplied by Sun Chemical Corp. The ink may be thinned 13 with a press solvent to a running viscosity of 20-22 seconds 14 as measured using a No. 2 Zahn Cup. The solvent may be a 1 15 mixture of 75% normal propyl alcohol, 25% ethyl acetate and 1 16 5% "EKTOSOLVE" (Chemcentral, ethylene glycol monoethyl ethyl i~ 17 ether).
18 The following has been used for the lower or easier .9 release coati~g 33, in weight percentages:
2096.10% DOW SLYOFF 7044 (100% solid, rhodium precatalyzed 21 organofunctional siloxane easy release polymer) 223.90% DOW Q2-7048 (100% solid, reactive , 23 polymethylhydrogen siloxane, crosslinker polymer) 1 24 This coating was applied at l.S grams per square ! 25 meter.
I 26 The following has been used for the higher or harder 27 release coating 35:
2851.00% DOW SYLOFF 7044 (100% solid, rhodium precatalysed 29 organofunctional siloxane easy release polymer) 3044.50% DOW Q2-7069 (100% solid, rhodium precatalyæed 31 organofunctional siloxane high release polymer) 324.50% DOW Q2-7048 (100% solid, reactive polymethylhydrogen 33 siloxane, crosslinker polymer).
34 This coating was applied at 1.4 grams per square meter.
A suitable choice for liner in the practice of the 36 invention as above described is 80# "SUPER TOUGH" paper (Otis 37 Paper).

` ~ ~ .U~U '~EE~

. ~,, ., ,,, ,.. , .. .. ~ ~

~;i 213~611 Q3 ~ r ~r~ ~ 1 8 hPR 1994 1 Similar practices may be utilized in the manufacture of 2 improved diaper fastener-tab stock adapted to be supplied to 3 a diaper manufacturer and to be separated by the manufacturer 4 into individual diaper-fastening tabs and applied to - 5 individual d~apQrs, usually two tabs to a diaper for infant 6 and two to six for adults.
7 The individual fastener 50 seen in FIG. g is, in effect, 8 a cross-sectional view of the diaper fastener stock from which 9 the individual fastener has been formed by transverse cuts.
This stock, then, consists of initially flat but flexible 11 first and second substrates 52 and 54 suitable to be formed 12 in long passes along the machine direction (into the paper as 13 viewed in FIGS. 7-9) of a coating and lamina~ing line without 14 ~he necessity for folding operations and completely by web coating, slitting and web-to-web laminating operations, and 16 suitable for high-speed dispensing on automatic equipment.
~7 The substrates may be polypropylene film 4.6 mils in 18 thickr.ess, for example.
19 The first or anchoring substrate 52 bears first substrate adhesive 56 on its underside. The first substrate 52 and the 21 first substrate adhesive 56 extend, transversely to machine 22 direction, along first and second length portions 61 and 62 23 of the we~ construction, respectively.
24 The second or additional substrate 54 bears second substrate adhesive 58 on its underside and also extends along 26 the first and second length portions 61 and 62. Release means 27 for the adhesive 58 of the second substrate 54 is carried on 28 the first substrate 52 and may be a release coat 64. This 29 release means extends along the second length,portion 62 but not significantly along the first length portion.
31 The first and second substrate adhesives may have the 32 following formu1ation:

AMtl~ D Sl!~T

` 2~356~ TIUS93/0356 5 03 ~ P`~ 1 8 ~P~ 199 1 KRATON 1107 (Shell Chemical, polystyrene- 31.7%
2 isoprene-polystyrene linear block copolymer) 3 ESCOREZ 1310LC (Exxon Chemical, solid C5 `46.3%
4 tackifying resin) WINGTACK 10 (Goodyear Chemical, solid C5 19.8%
6 tackifying resin) ~ ETHANOX 330 (Ethyl Corp~, phenolic anti- 1.0%
8 oxident) 9 PLASTONOX LTDP (American Cyanamid, thioester 1.2%
anti-oxident)--.
11A suitable masking or barrier may be formed by printing, 12using as the ink "SUNTEX 182 PINK" CLA 40457F ink supplied by 13 Sun Chemical Corp. The ink may be thinned with the same press 14 solvent given previously, to the same running vi-cosity.
The second substrate construction as seen in FIG. 7 is 16 formed in a manner similar to the formation of the tape seen 17 in FIG. 5. The substrate 54 is formed from a substrate twice 18 as wide by slitting after being coated with the adhesive 58 19 and after adhesive barrier means 57 is printed on the adhesive along a continuous zone or line at the midline of the original 21 or unslit substrate.
22 Preferably, the barrier means 57 is an ink or other 23 barrier of a color which contrasts with the color of the 24 adhesive. (If desired, the substrate 54 may be provided at its correspondin~ edge with corresponding coloring, not shown, 26 which contrasts with the remainder of the substrate. This can 27 be done by known printing or coextrusion techniques. Slitting 28 produces two tapes, mirror images of each other, one of which 29 is the tape seen in FIG. 7, which includes the adhesive masking portion 57.
31 The first substrate portion as seen in FIG. 8 is formed 32 by conventional coating techniques and may al~so represent a 33 half-width of original substrate stock slit down the middle.
34 The tapes as seen in FIGS. 7 and 8 can be cut from original or unslit substrates which are combined prior to slitting, or 36 can be combined follo- ~g slitting of the original or unslit 37 substrates. In any e .~t, when the constructions of FIGS. 7 38 and 8 are laminated together to form the diaper fastener stock 39 illustrated in FIG. 9, the masking portion 57 is contained ` A~tEi~DEDSHE~

P~T/~ls 9 3 / 0 3 5 6 ;5 21 3 5 6 1 1 -15- 0~ R' ~ p,!~ 199 1 snugly within the associated end of the lamination to provide 2 built-in end tab means.
3 Suitable release means may be provided to allow the 4 construction as so far described to be self-wound for storage 5- and shipment. Such release means may be a release co~t G6 on 6 the second substrate 54. When the diaper fasten~r stock is 7 wound on itself, the first substrate adhesive 56 is releasably 8 supported against the release coat 66, and readily separates 9 therefrom when the roll is subsequently unwound on a diaper manufacturing line.
11 When the diaper fastener stock is wound as just 12 described, the built-in end tab afforded by the masking 13 portion 57 and associated overlying portion of substrate 54 14 allows the roll to form evenly without build-up of one side, 15 and presents evenly thick edges which are supported from one 16 turn to the nest in the wound roll.
17 On the manufacturing line, the diaper fastener stock is 18 unwound and cut t~ansversely to form a series of individual 19 fasteners which are applied, usually in pairs, to individual diapers by being folded around a diaper edge. FIG. 10 shows 21 an individual fastener cut from the stock described above 22 applied around the edge of a diaper 70. This is the 23 undeployed condition of the diaper fastener. Fasteners made 24 according to the invention have been found to perform satisfactorily when applied to Huggies Super Trim diapers 26 (Kimberly Clark) which, as is typical of many contemporary 27 disposable diaper constructions, have a fastener-receiving 28 frontal tape to reinforce the relatively fragile and easily 29 torn diaper outer plastic shell or envelope. , FIG. 11 illustrates the deployed condition of the diaper 31 fastener. When a diaper is applied to an infant or other 32 person, each diaper fastener is moved from undeployed to 33 deployed condition. The second length portion of the second 34 substrate 54 constitutes deployment means separable from the second length portion of the first or anchoring substrate 52 36 for deployment as shown in FIG. ll and adherence to another Ei~Oc5 SHEEr ~- 213~611 .
-16- PCTlUS 9 3 1 0 3 5 6 ~
a3 ~ r~ 8 ~,P.~ 19,¢
1 portion of the diaper (not shown) by application of the 2 exposed second length portion of the second substrate adhesive 3 58 to such other diaper portion. The end-tab means comprising 4 masking portion 57 is at the free end of such deployment means.
6 In other words, the second substrate 54 will be seen to 7 constitute substrate means which has an inner and an outer 8 end, and which is fastened at its inner end to one part of the 9 diaper via the adhesive layers 56 and 58 and the substrate 52 (FIG. 10). The tape will be seen to have a pressure-sensitive 11 adhesive face 59 (FIG. ll) at least at the outer end of such 12 substrate means, such face being carried on release means 64 13 which in turn is carried on the same part of the diaper via 14 the substrate 52 and adhesive 56 (FIG. lO). The second substrate is adapted to have its outer end peeled from and 16 thereby deployed from the part of the diaper seen in FIGS. 10 17 and 11 for fastenin~ to another part of the diaper (not shown) 18 to thereby establish a user joir.t and fasten the diaper. The 19 outer end of the second substrate has lift tab means in the form of the masking portion 57 for initiating peeling of the 21 outer end from the release means 64.
22 The barrier means or masking portion may, if desired, be 23 provided with fragrances, which may simply be added to a 24 printing ink. Absorbent powders in the ink may function to pick off finger oils of the parent or other caregiver who 26 handles the diaper tab, thereby reducing the likelihood of 27 contamination of the bonding interface established when the 28 tab is fastened. The ingredients of the barrier or masking 29 may have a double function, for example an absorbent powder may contribute both to deactivating or masking the pressure-31 sensitive adhesive and to absorbing finger oils.
32 Many variations in the specific example described above 33 are possible. FIG. 12 shows a variant in which the invention 34 is incorporated in a diaper fastener of the general type shown in U.S. Patent No. 4,020,842 to Richman et al. the disclosure 36 of which is incorporated by reference as if fully repeated ` -,, ,"

t` 2135611 P~T/US93fO356~
-17- n~ r ~ ~ 1 8 ~PR 199' ~ herein. This type ~f fastener has more than one additional 2 substrate and correspondingly more than one deploy~ent means.
3 In the construction of FIG. 12, a first or anchoring substrate 4 52 and a second or additional substrate 54, and associated S first and second substrate adhesives 56 and 58, are pr~~ded 6 similarly to the construction of FIG. 9. Further, a third 7 substrate 74 (constituting a second additional substrate) is 8 provided along with associated third substrate adhesive 76.
g Since this substrate is the outermost in this construction, a release means such as the release coat 77 is provided along 11 the entire length of the substrate for self-winding purposes.
1~ The release coat 66 of the FIG. g construction is replaced by 13 shortened release coat 66a which extends along the second 14 length portion corresponding to length portion 62 in FIG. 9, but not significantly along the first length portion 16 corresponding to length portion 61 in FIG. 9. Preferably, the 17 substrate adhesives 58 and 76 are interrupted at the fold-18 around portion of the diaper fastener by adhesive gaps 58g and 19 76g.
The second substrate 54 of the FIG. 12 construction is 21 interrupted by a slit or small gap 72. The general operation 22 of the construction in the manner of deployment, reopening and 23 reclosing is the same as that of the aforesaid Richman et al.
24 patent. However end-tab means of the general kind intended by the present invention is provided on at least one of the 26 deploying substrates. In this case, end-tab means comprising 27 the printed masking portion 57a is provided in association 28 with the free end of substrate 54, and end-tab means 29 comprising the printed masking portion 57b ~s provided in association with the free end of substrate 74.
31 Still other forms of diaper fasteners utilizing the 32 invention may be provided. Thus a type of two-substrate tab 33 may be provided wherein both substrates perform an anchoring 34 function, and less substrate material is used than in the designs previously described.
36 Such diaper tab stock may be first combined on the diaper 41~E'~!ûE5 SHEET

21:~`5611 -18- PcT/us~ 3 / 0 3 56 ~ -03 R~ 8 ~P~ 1994 1 manufacturing line f~om stock components made by different 2 manufacturers. For example the two substrates an~ associated 3 adhesives and release coats may be provided in self-wound form 4 from different sources or from a single source.
Thus as shown in FIGS. 13-17, first and sec~n~ substlates 6 82 and 84 are provided with first and second substrate 7 adhesives 86 and 88, and release coats 94 and 96 are provided 8 on the first and second substrates. In the industry, the 9 first and second substrates together with associated adhesives and coatings are often referred to respectively as release 11 tape stock and fastener tape stock. The diaper manufacturer 12 combines the release tape stock or substrate 82 and the 13 fastening tape stock or substrate 84 in the~manner shown in 14 FIG. 15, then cuts the combined tape stock into individual fastener tapes and applies successive fasteners around a 16 diaper edge in the manner seen in FIG. 16. Fastener tapes for 17 the opposite side edge of the diaper are formed and combined 18 in the mirror image of the illustrated tape.
19 The second substratè 84 will be seen to constitute substrate means which has an inner and an outer end, and which 21 is directly fastened at its inner end to one part of the 22 diaper by the adhesive layer 88. (FIG. 16). The tape will be 23 seen to have a pressure-sensitive adhesive face 89 (FIG. 17) 24 at least at the outer end of such substrate means, such face being carried on release means 94 which in turn is carried on 26 the same part of the diaper via the substrate 82 and adhesive 27 86 ~FIG. 16). The second substrate is adapted to have its 28 outer end peeled from and thereby deployed from the part of 29 the diaper seen in FIGS. 16 and 17 for faste~ing to another part of the diaper (not shown) to thereby establish a user 31 joint and fasten the diaper. The outer end of the second 32 substrate has lift tab means in the form of the masking 33 portion or barrier means 87 for initiating peeling of the 34 outer end from the release means 94.
In this construction, the release coat 94 serves two 36 release functions; it allows self-winding of the substrate 82 2 1 3 i 6 1 1 -19- P~T/us ~ 3 / 0 3 5 6 ~?5 03 ~?~,r'C~ F~n'. tr~-~ 1 8 APR 1994 1 for shipment from the tape stock manufacturer to the diaper 2 manufacturer and it serves as the release face against which 3 the adhesive face 89 is stored in the conditions shown in 4 FIGS. 15 and 16. The release coat 96 performs the single release function; it allows self-winding of the substrate 84 6 for shipment.
7 The various slitting, patterning and combining operations 8 at the fingerlift end of the diaper fastener stock can be 9 performed in duplicate at the web center on a stock manufacturing line, with the slitting, patterning and lI combining on one lateral side of the infed webs being done in 12 mirror image to the same operations on the other side. In 13 such case, of course, the width of the infed webs is at least 14 double the width of the resulting diaper fastener stock.
It is to be noted that in all instances the end-tab means 16 is located within the length of the longest of the one or more 17 additional or deployment substrates.
18 The result is a diaper tab fastener with a fingerlift 19 superior to those of the prior art discussed above. The end-tab means of the invention can be readily and conveniently 21 grasped and manipulated by the person applying the diaper.
22 The end-tab means can be readily fabricated on a diaper 23 fastener stock production line by simple patterning and 24 slitting steps that are fully compatible with economical high speed production. The stock can be self-rolled in smooth, 26 uniform rolls that are free of local high spots and resulting 27 distortions.
28 The invention is not limited to the specific details of 29 the disclosed embodiments, but is defined in, the following claims. `

AMENDE~ SHEE~

Claims

WHAT IS CLAIMED IS:

1. A method of forming at least one slit-to-order relatively narrow pressure-sensitive adhesive tape from an inventory including a relatively wide roll of pressure-sensitive adhesive tape stock comprising a substrate coated with a layer of pressure-sensitive adhesive, the method comprising the steps of unwinding the relatively wide roll of pressure-sensitive adhesive tape stock, combining adhesive-inhibiting masking with the adhesive of said unwound stock along a continuous machine-direction line at an intermediate point across the width of the unwound stock corresponding in width with said at least one slit-to-order tape, and slitting said substrate, adhesive layer and masking along said line to form said at least one slit tape narrower in width than said roll of tape stock.

2. A method of manufacturing self-wound pressure-sensitive-adhesive transfer tapes including a substrate having first and second faces comprising combining release means with the first and second faces of the substrate with the second face having the easier release; combining a layer of pressure-sensitive adhesive with the first face of said substrate, combining adhesive-inhibiting masking with said adhesive along a continuous machine-direction line or lines, and slitting said substrate, adhesive layer and masking along said line or lines to form at least one slit tape having an edge thickness substantially equal to the average thickness of the tape across its width.

3. A method as in the preceding claim in which at least two slit tapes are formed in said slitting step, and including the steps of winding the slit tapes into slit rolls, and subsequently unwinding at least one of said slit rolls, combining additional adhesive-inhibiting masking with the adhesive of said slit roll along a continuous machine-direction line or lines at an intermediate point or points across the width of the slit roll, and slitting said substrate, adhesive layer and masking along said line or lines to form at least one additional slit tape narrower than the tape forming said slit roll.

4. A method of manufacturing pressure-sensitive tape comprising the steps of feeding a substrate along a manufacturing line, combining a layer of pressure-sensitive adhesive with a first face of said substrate, printing said layer of pressure-sensitive adhesive with a patterned adhesive-inhibiting masking to define a masking pattern comprising at least one continuous line, slitting said substrate, adhesive layer and masking along said at least one continuous line defined by said pattern coating to form a slit tape having an edge thickness substantially equal to the average thickness of the tape across its width, and further processing said slit tape by releasably combining the side of said pressure-sensitive adhesive layer bearing said masking against a second substrate face, said second substrate face comprising an opposite face of said first-named substrate to thereby produce a self-wound tape, or comprising an exterior face of an additional substrate to thereby produce a multisubstrate tape.

5. A method as in claim 4 in which said combining of said pressure-sensitive layer against said second substrate face is preceded by the coating of at least parts of said second substrate face with a release coating.

6. In a diaper having adhesive fastener tapes, each fastener tape having a width and having substrate means for providing a substrate, said substrate means having an inner and an outer end and being fastened at its inner end to one part of the diaper, each tape having a pressure-sensitive adhesive face at least at the outer end of said substrate means, said face being carried on release means for providing a release face, said release means in turn being carried on said one part of the diaper, said substrate means being adapted to have its outer end peeled from and thereby deployed from said one part of the diaper for fastening to another part of the diaper to thereby establish a user joint and fasten the diaper, said user joint being openable by peeling said outer end from said another part of the diaper, being refastenable by reapplying said outer end to said another part of the diaper to reestablish said user joint, and being reopenable following said refastening, said adhesive face being liftably peelable from said release face of said release means to effect said deployment, the outer end of said substrate means having lift tab means for initiating said peeling of said outer end, the improvement comprising providing said lift tab means in the form of a printed adhesive-inhibiting liftable masking means for inhibiting adherence of the adhesive face, said masking means being provided on the adhesive face at the outermost part of said outer end and extending across said width of said tape, said masking means being liftable along with said adhesive face for initiating said peeling from said one part of the diaper, and said masking means being thereafter reusable both (1) to open said user joint and (2) to subsequently reopen said user joint after refastening thereof.

7. A diaper as in claim 6, said adhesive-inhibiting masking means being in liftable contact with said release face prior to said peeling of said outer end.

8. A diaper as in claim 7, said adhesive-inhibiting masking means extending across the entirety of said width of said tape.

9. A diaper as in claim 8, said outer end of said substrate means having an outer-end boundary and said tape, adhesive face and adhesive-inhibiting masking means having outer-end extremities, said tape having a slit-formed outer-end edge intersecting, and defining said outer-end extremities of, said tape, said adhesive face and said adhesive-inhibiting masking means, said outer-end boundary of said substrata means being congruent with said outer-end edge of said tape.

10. In a diaper fastener formed of a web construction of linerless reclosable diaper fastener stock made up of initially flat but flexible layers, including substrates and adhesive layers, said stock being suitable to be formed in long passes along the machine direction of a coating and laminating line and to be rolled up for storage and shipment, and unrolled for use by diaper manufacturers, and fabricatable completely by web coating, slitting and web-to-web laminating operations and without the necessity for folding operations and usable for high speed dispensing on automatic equipment, including a first innermost substrate bearing first substrate adhesive on its underside, and extending, transversely to machine direction, along first and second length portions, and at least one additional substrate bearing on its underside at least one corresponding additional substrate adhesive and extending along said first and second length portions, said fastener having a width and being mountable around an edge of a diaper with said first substrate constituting an anchoring substrate and said second length portion of said at least one additional substrate and corresponding substrate adhesive comprising deployment means having a fixed end and a free end and separable at said free end from said second length portion of said anchoring substrate by lifting of said at least one additional substrate to peel and lift said corresponding additional substrate adhesive from contact with said anchoring substrate for deployment of said additional substrate and additional substrate adhesive and engagement of said additional substrate adhesive with another part of the diaper, said free end being (1) separable from said another part of the diaper together with said additional substrate and additional substrate adhesive, (2) reapplicable to said another part of the diaper for reengagement of said additional substrate adhesive with said another part of the diaper, and (3) reseparable from said another part of the diaper following said reapplication thereto, and end-tab means associated with the free end of said deployment means, the improvement wherein said end tab means associated with at least one of said at least one or more additional substrates is defined by adhesive-inhibiting liftable masking means printed on the substrate adhesive associated with said at least one substrate and extending across said width of said fastener, said liftable masking means being liftable along with said associated adhesive to initiate the peeling and lifting of the at least one additional substrate, and said liftable masking means being reusable to separate said associated adhesive from said another part of the diaper after its engagement therewith and being further reusable to reseparate said associated adhesive from said another part after its reengagement therewith.

11. A construction as in claim 10 in which the thickness of said masking means is less than 1 percent of the combined thickness of the associated substrate and substrate adhesive, whereby said diaper fastener stock from which the fastener is formed has a substantially uniform edge-to-edge thickness, said stock may be tightly rolled, and the layer edges at both sides of rolls of said stock are solidly supported by adjacent layer edges.

12. A construction as in claim 10, release means at said second length portion of the substrate that is immediately below said at least one of said at least one or more additional substrates ?aid release means presenting a release face to the substrate adhesive associated with said at least one substrate, said adhesive-inhibiting masking means being in liftable contact with said release face prior to said deployment.