Source: https://patents.google.com/patent/AU607603B2/en
Timestamp: 2019-04-19 07:40:53
Document Index: 394593491

Matched Legal Cases: ['§2', '§2', 'art 2', '§2', '§2', 'arts 1']

AU607603B2 - Pressure-sensitive adhesive having improved adhesion to plasticized vinyl substrates - Google Patents
AU607603B2
AU607603B2 AU33034/89A AU3303489A AU607603B2 AU 607603 B2 AU607603 B2 AU 607603B2 AU 33034/89 A AU33034/89 A AU 33034/89A AU 3303489 A AU3303489 A AU 3303489A AU 607603 B2 AU607603 B2 AU 607603B2
AU33034/89A
AU3303489A (en
Donald Timothy Landin
1988-05-20 Priority to US07/196,441 priority Critical patent/US4946742A/en
1988-05-20 Priority to US196441 priority
1989-11-23 Publication of AU3303489A publication Critical patent/AU3303489A/en
1991-03-07 Publication of AU607603B2 publication Critical patent/AU607603B2/en
6 0 7 E 63 S F Ref: 92888 FORM COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION
FOR OFFICE USE: Class Int Class Complete Specification Lodged: Accepted: Published: Priority: Related Art: t. rc I c- '4I i 14~r~CA'Zl i gy, of Applicant: Address for Service: Minnesota Mining and Manufacturing Company 3M Center Saint Paul Minnesota 55144-1000 UNITED STATES OF AMERICA Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Complete Specification for the invention entitled: Pressure-Sensitive Adhesive Having improved Adhesion to Plasticized Vinyl Substrates The following statement is a full description of this invention, including the best method of performing it known to me/us 5845 /8
ACCEPTED AND AMENDMENTS 5845/7 -1- Abstract Normally tacky and pressure-sensitive adhesive, having excellent long-term adhesion to plasticized vinyl substrates, is prepared from a representative blend of dioctyl phthalate plasticizer and a copolymer of isooctyl acrylate, N-vinyl pyrrolidone, and acrylic acid; alternatives for each component are disclosed. In a preferred embodiment of the invention, the adhesive is coated in a thin layer on a sheet backing material to form a normally tacky and pressure-sensitive adhesive tape.
Sf t ST t It t o- e t 230 Ji3 25 V
i C1 L j~i.-P- -lA- 42591AUS 1A PRESSURE-SENSITIVE ADHESIVE HAVING IMPROVED ADHESION TO PLASTICIZED VINYL SUBSTRATES Background of the Invention k ;i 0.1 -0 646: 0.s '3 0 0 ao o f o a 00 00 0 0 00 C Cs This invention relates to normally tacky and pressure-sensitive adhesive (PSA) compositions and to PSA tapes made therewith. The invention is particularly concerned with PSA products capable of adhering firmly to plasticized vinyl substrates, both initially and after contact over an extended period of time.
Polyvinyl chloride (or, as it is more commonly referred to, "vinyl") is one of the most versatile and widely used synthetic polymers available today. In its 15 unmodified form, it is rigid and capable of being fabricated into containers, structural components, tubing, etc. When compounded with a plasticizer, it can be calendered into flexible sheet material that can be used as upholstery fabric, floor covering, PSA tape backing, 20 rainwear, etc., or extruded as electrical insulatioi, auto body side moulding, etc. Plasticized vinyls typical v contain 15-50% by weight of either a mononeric or a polymeric plasticizer; because the monomeric plasticizers are less expensive, they are more commonly employed.
Unfortunately, however, the monomeric plasticizers are of relatively low molecular weight, tending not only to migrate to the surface of the plasticized vinyls but also to volatilize therefrom, gradually embrittling the originally flexible product.
30 The tendency of plasticizer to migrate into materials with which it comes in contact is also well known; see, U.S. Pat. No. 4,284,681. Thus, when a PSA is applied to a plasticized vinyl substrate and allowed to remain in contact with it for an extended period of time, '4
L 1 I, ii~.i- iY -2plasticizer from the vinyl tends to migrate into the PSA, softening it and causing a decrease in adhesion; see, e.g., U.K. Pat. No. 1,051,125.
Attempts have been made to solve the plasticizer migration problem by interposing an impenetrable barrier between the vinyl and the PSA; see, U.S. Pats. No.
4,045,600 and 4,605,592. Others have developed PSAs that are said to be less susceptible to weakening by plasticizer; see, Graziano et al, Development of Acrylic Latex Pressure Sensitive Adhesive for Plasticized PVC films, Journal of Plastic Film Sheeting, Vol. 2, April 1986, pp. 95-110. A commercially available tape that is widely used for adhering to plasticized vinyl utilizes a PSA that is a terpolymer of 2-ethyl hexyl acrylate, vinyl acetate, and ethyl acrylate.
Another attempt to prevent migration of plasticizer from a plasticized vinyl substrate into a tc confronting PSA has been to incorporate plasticizer into the PSA, thereby minimizing the plasticizer gradient 20 between the contacting layers; see, US. Pat. No.
S t 4,272,573, U.K. Pat. App. 2,162,191-A, and European Pat. i App. 150,978.
tDespite the limited success achieved by products of the type discussed in preceding paragraphs, there has remained a strong commercial desire for a PSA that was more •fr effective, particularly one that not only initially adhered t strongly to plasticized vinyl but which also retained a high degree of adhesion after remaining in contact with it for extended periods of time. In particular, none of the t 4 30 prior art products have been able to provide excellent resistance to shear after prolonged contact with plasticized vinyl.
Brief Summary The present invention provides a PSA having excellent initial adhesion to plasticized vinyl substrates.
i. i' :t ii c"* f.
C CI t r
t r It sr C I C t C CC Even more significant, however, is the fact that excellent adhesion is maintained after the PSA has been in contact with the vinyl for extended periods of time. In accordance with the invention, it is also possible to provide a PSA that retains excellent shear adhesion after prolonged contact with a plasticized vinyl substrate.
The invention comprises a polymer of monomers consisting essentially of 60-88 parts by weight of acrylic acid ester of nontertiary alkyl alcohol containing 4-14 carbon atoms, such as butyl acrylate, or especially isooctyl acrylate or isononyl acrylate, 2-30 parts by weight of polar nitrogen-containing vinyl monomer, such as N-vinyl pyrrolidone, N-vinyl caprolactone, N,N-pentaethylene acrylamide, or N,N-dimethyl acrylamide, and (3) car b c.
0-12 parts of vinyllacid such as acrylic acid, methacrylic acid, or itaconic acid. Intimately blended with the polymer, in an amount suitable to achieve the desired degree of pressure-sensitive adhesion, is a plasticizer such as dioctyl phthalate (DOP), 2-ethyl hexyl phosphate 20 (2EHP), or tricresyl phosphate (TCP). The amount of plasticizer generally constitutes 2-35% (preferably 2-10%) by weight of the PSA. In most cases, the PSA will be in the form of a thin layer carried by a backing to which it may be either permanently or temporarily adhered. Where the PSA is permanently adheted, the resultant product is a normally tacky and pressure-sorsitive adhesive tape. Where the backing is provided wilh release coating, the PSA is in the form of a so-calleo transfer tape.
Where a PSA ha.vig excellent shear adhesion to plasticized vinyl is desired, an effective amount of crosslinking agent 0.15 part of a photoreactive s-triazine) may be added to the PSA. Presently preferred crosslinking agents include §2,4-bistrichloromethyl-6(4-methoxyphenyl)-s-triazinet, and §2,4-bistrichloromethyl-6(3,4-dimethoxyphenyl)-s-triazinet.
It is surprising that an extremely small amount of plasticizer (as low as in the PSA is effective to i
-4r r r t t t 0C C
r C C I C C C C
c: CC C Ce impart excellent adhesion to vinyl containing as much as monomeric plasticizer. It is also surprising that the plasticizer in the PSA need not be the same as the plasticizer in the vinyl. It has been found empirically that the unpredictably good adhesion, even after extended heat aging, flows from the incorporation of the polar N-containing vinyl monomer, although the reason is not fully understood.
900 Peel Adhesion. This test is conducted in accordance with a modified version of PSTC-14, a procedure specified in "Test Methods for Pressure-Sensitive Tapes," 8th edition, available from the Pressure-Sensitive Tape Council, 1800 Pickwick Ave., Glenview, IL 60025-1377, U.S.A. A.strip of the tape to'be te.sted, 2.54 cm wide x cm. long, is adhered to a test panel, which in turn is mounted on a sled and clamped horizontally in the lower jaw of a tensile testing machine. One end of the tape is then stripped away and clamped in the upper jaw of the tensile tester. The jaws are then separated at approximately 30.5 cm/minute while measuring the force required to remove the tape at an angle of 90 Results are measured in oz/inch of width and converted to N/dm.
1800 Peel Adhesion. This test is conducted in accordance with PSTC-7, a procedure specified in the same publication referred to above. A strip of tape 12.7 mm wide and about 30 cm long is adhered to a panel about 5 cm x 12.5 cm. One end of the tape is then doubled back on itself to expose about 2.5 cm at the end of the panel.
This exposed end is then clamped in the upper jaws of a tensile testing machine and the doubled-back free end of the tape clamped in the lower jaws. The jaws are then separated at about 30 cm/minute. The force required to
i' -cl strip the tape from the panel is measured in oz/1/2 inch and reported as N/dm.
T-Peel Adhesion. A 25.4-cm x 10-cm strip of the tape to be tested is laminated to a flexible strip of the substrate to which, adhesion is to be determined. The two strips of the 4-cm length adjacent one end are separated and clamped in the upper and lower jaws of a tensile tester respectively. The jaws are then moved apart at approximately 30 cm/minute while measuring the force required to separate the two strips.
Shear Adhesion. This test is conducted in accordance with PSTC-7, a procedure specified in the same publication referred to above. A 12.7-mm x 10-cm strip of the tape to be tested is applied to a vertical test panel o, 15 so that a terminal 25.4-mm x 12.7-mm area is in contact. A 0 weight of either 250 or 500 grams is then applied to the 04 04 S0 free end of the tape and the time to failure noted. If no 0oo oo failure has occurred in 10,000 minutes, the test is discontinued.
o D 0, a 20 Understanding of the invention will be enhanced by referring to the following examples, in which all parts and percentages are by weight unless otherwise noted.
t t C Example 1 A pressure-sensitive adhesive tape was made by S partially photopolymerizing a mixture of 60 parts isooctyl acrylate (IOA) and 24 parts N-vinyl pyrrolidone (NVP) in the presence of 0.04 part 2,2-dimethoxy-2-phenyl acetophenone (IRG 651) photocatalyst. The partial photopolymerizing was accomplished in an inert (nitrogen) atmosphere using a bank of 40-watt fluorescent black lights y' (Sylvania model no. F48T12/22011/40) to provide a coatable syrup having a viscosity of about 1.5 Pa.s. To this syrup was then added 2 parts acrylic acid 14 parts DOP plasticizer, 0.15 part §2,4-bistrichloromethyl- 6(4-methoxyphenyl)-s-triazinet, a photoreactive s-triazine crosslinking agent (XL-353), and 0.10 part IRG 651 t 1 1 -6photocatalyst. The mixture was knife coated onto a first biaxially oriented polyethylene terephthalate film and covered by a second such film at a knife setting which was adjusted to squeeze the syrup to provide a uniform coating about 0.127 mm thick, the surfaces of the two films in contact with the adhesive composition having previously been provided with low adhesion release coatings. The composite was exposed to a bank of Sylvania ultraviolet fluorescent lamps, providing ultraviolet 2 radiation at a rate of 1 mw/sec/cm 2 Example 2 Same as Example 1 except that the IOA:NVP:AA:DOP ratio was 60:21.8:7.6:10.6.
o 0 o Example 3 o 0 Same as Example 1 except that the IOA:NVP:AA:DOP "o ratio was 69:17:4:10 and the DOP plasticizer was replaced o0 o0 o0 with TCP.
0 0 o a 0 Example 4 Same as Example 1 except that the IOA:NVP:AA:DOP I ratio was 69:17:4:10 and the XL-353 crosslinker was replaced with §2,4-bistrichloromethyl-6(4-methoxyphenyl)- 25 s-triazinet.
I rt Example Same as Example 4 except that the IOA:NVP:AA:DOP ratio was 67.6:22.5:2.0:7.9.
I S Example 6 Same as Example 4 except that the IOA:NVP:AA:DOP ratio was 68:25:2:5.
Example 7 Same as Example 4 except that the IOA was replaced by isoi nyl acrylate (INA).
-7- Example 8 Same as Example 4 except that the IOA was replaced by butyl acrylate (BA).
Example 15 An 80:20 IOA:NVP was prepared, as was a 90:10 SI IOA:AA syrup. Equal parts of the two syrups and DOP were then blended, after which photopolymerization was t ,t r completed. The resultant adhesive thus had an IOA:NVP:AA:DOP ratio of 66:6.6:3.3:33.
S Example 11 (An 80:20 IOA:NVP copolymer was prepared; 67 parts 1 t of this copolymer was then blended with 7.5 parts AA and 25.5 parts DOP, after which photopolymerization was completed. The resultant adhesive thus had an IOA:NVP:AA:DOP ratio of 53.6:13.4:7.5:25.5.
Cr T CExample 12 SSame as Example 4 except that the 17 parts of NVP S c r 30 was replaced with 17 parts of N,N-dimethylacrylamide.
rl -r" rC-rCL IU~M rP-~-LII-YU~r~ 3~C-~
.It .g Iri I b ii :t i aft 0 00 0 o 0 o6 4 090* 00 O 0 0 60 00h tl 4< 4 14 t 4tt 4 t Lt<4 The tapes of Examples 1-11 and Control A were then evaluated for their adhesion to two types of plasticized vinyl, viz., a black electrical cable jicketing plasticized with 33.8% 2EHP and a decorative trim strip plasticized with 27.8% 2EHP. Duplicate samples of each tape were adhered to each of the two test panels. One taped panel of each pair was allowed to stand at room temperature (RT) for three days, while the other taped panel of each pair was placed in a 700C oven for one week. (It is believed that exposure at HT for one week 15 corresponds to exposure at RT for about one year.) As a frame of reference, the best commercially available tape for adhesion to plasticized vinyl was subjected to the same conditions. (The control tape, identified as "Control B" had a 12.5-micrometer polyester film backing coated on each side with a 57-micrometer layer of a PSA believed to be a 2-ethyl hexyl acrylate:ethyl acrylate copolymer blended with a vinyl acetate polymer.) 180o peel adhesion tests were then performed, with the following results: 0009 09 00 00 0 o 0 0 0 00 00 00 0 0 0 00 0 0 0 1 4 4 4 4 4<4< to t 0 4<l 04 4< 4<4
CO~ d COr
4< 25 ;i 1 r at" (a
5 Exampl 1 2 3 4 6 10 7 10 8 9 11 12 13 Con tro 15 Contro The ta f or ad varyin 20 the ta prior after tests panel 25 weight r 6
Semi-r
Flexib Highly tici Stainl Stee I~ IL"-LI-X~1" -i VL~E ~uusl Du-u*ln~sr~ -9- TABLE I Adhesion, N/dm, to Substrate after Exposure Indicated Example No 1 2 3 4 6 7 8 9 11 12 13 Control A 15 Control B Cable Jacketing RT HT 59 46 81 61 70 53 61 57 99 66 79 31 48 35 57 59 66 59 Vinyl Trim RT HT 61 44 74 79 42 61 46 77 66 83 42 77 28 59 48 74 66 72 39 118 110 77 125 83 48 26
0 a* 00 o 0 0 0 0 0 0 0 o Qo 0 0 0 00 0 oa 0 0 0 0 o t tt toot The tape of Example 4 was then compared to Control tape B for adhesion to the surface of vinyl bars containing varying degrees of plasticizer. In each case, a roll of 20 the tape to be tested was placed in a 700 C oven for 3 days prior to testing. 900 peel adhesion tests were performed after aging the taped substrate one week at 700 C. Shear tests were performed at 700 C. using a stainless steel panel as the substrate and applying either a 250-g or 500-g weight. Results are tabulated below: TABLE II Comparative Adhesion and Shear Tests C Cr C t t 30 900 Peel Adhesion N/dm Substrate Control B Example 4 Shear Adhesion at 700 Minutes Control B Example 4 UPVC 114 Semi-rigid PVC 103 Flexible PVC 30 Highly plasticized PVC 19 Stainless Steel 256
I Ir ij i i i i 1; c 1,728 10,000+ (250 g) (500 g) ~L -i It will be noted that, in almost every instance, the peel adhesion of the tape made according to the present invention was significantly better than the best prior art tape commercially available. It will also be noted that the shear adhesion of the experimental tape was dramatically superior to that of the prior art product.
Using azobisisobutyronitrile as a thermal initiator, two different copolymers were prepared as solids solutions in ethyl acetate at 55 the first having a 69:17:4:10 IOA:NVP:AA:DOP ratio and the second having a 77:19:4 IOA:NVP:AA monomer ratio. Each of the two solutions was then diluted to 25% solids by adding ethyl acetate. Four additional examples and a control were s t t prepared from these copolymers as described below: Example 14 To the first copolymer described in the preceding paragraph was added 0.5% of a,proprietary crosslinking j t agent, based on the polymer solids. The resulting solution was then coated on a polyethylene-coated paper backing and the solvent evaporated in a 1500 C. oven over a ten-minute period to leave a 127-micrometer adhesive coating.
iExample Same as Example 14 except that crosslinking was effected under U.V. light with 0.15% of the s-triazine crosslinker of Example 4.
|Example 16 To the second copolymer described above was added tS i0.5% of the proprietary crosslinking agent of Example 8, Sand 10% DOP. The resulting solution was then coated on a polyethylene-coated paper backing and the solvent evaporated to leave a 127-micrometer adhesive coating.
-11- Example 17 Same as Example 16 except that crosslinking was effected under U.V. light with 0.15% of the triazine of Example 4.
900 peel adhesion tests were run against vinyl trim and cable jacketing substrates with each of tapes 14-17 inclusive and the control. Duplicate samples were prepared, one being allowed to age 72 hours at room temperature and the other one week at 700 C. Results are tabulated below:
rC 4 It I I
CI II I 1.1
1.41 Example 14 16 17 Control C Cable Jacketing RT HT 146 76 146 78 136 78 144 64 38 10 Vinyl Trim RT HT 120 74 132 66 108 68 120 72 44 14 TABLE III 900 Peel Adhesion to Indicated Substrates, N/dm The tabulated data show that superior adhesion is obtained when the PSA is a copolymer of monomers essentially comprising polar N-containing vinyl monomer, in this case
As is apparent from the foregoing illustrative examples, numerous variations of the invention will occur to those skilled in the art who read this disclosure. A few general principles might be noted. When it is essential to have a PSA that possesses high shear adhesion for attachment to a vertical vinyl surface), crosslinking is desirable. It should be pointed out, however, that adhesives displaying high shear tend to lack i!
L; i ~-s week at 70 C.
2 -12ready conformability and "rapid wet out," or quick stick. When the amount Sof plasticizer in the adhesive is increased, a greater percentage of NVP or analogous monomers can be used. Increasing the amount of plasticizer, without further modification, tends to soften the adhesive and reduce its holding power.
Microbubbles of glass, polymeric or other suitable material can also be incorporated in adhesives made in accordance with the invention to achieve a foamlike product similar to that disclosed in U.S. Pat. No.
I 4,223,067. Transfer tapes made in this manner possess an apparently unique ability to bond firmly to the plasticized vinyl autobody moulding strips in widespread use.
Exaimles 19 and Plasticized adhesive compositions generally similar to those of Example 4 were prepared in essentially the same way and applied to the back surface of hook-and-loop fastener material of the type described in U.S.
Pat. No. 3,009,235. The backing of the fastener material was a woven nylon fabric, and the adhesive was applied in a layer about 0.25 mm thick.
T-peel adhesion tests were then run against a clear 0.375-mm vinyl substrate containing 26% of a semilinear phthalate (believed to be 2-ethyl hexyl phthalate) plasticizer, after 24 hours dwell at room temperature and after aging at 70° C for 7 days. Results are tabulated below: 1800 Peel adhesion, N/dm Example IOA:NVP:AA:DOP ratio Initial Heat-aged 18 67:28.6:2.2:2.2 224 156 19 65:28:2.7:4.3 219 163 These products were useful as closures for plasticized vinyl notebooks and blanket bags. Compared to the adhesive SiRLF/12 i
RLF/1219h e L_ i i 5845/8 -13on conventional hook-and-loop products, which is a ketone-actitiatable adhesive, the PSA on the products of Examples 18 and 19 were free from air pollution, more convenient, and faster bonding.
1. Normally tacky and pressure-sensitive adhesive having ability to bond to plasticized vinyl substrates and to remain bonded thereto comprising: a copolymer of 100 parts by weight of monomers consisting essentially of 60-88 parts by weight of acrylic acid ester of non-tertiary 4-14 carbon alcohol, 2-30 parts by weight of polar nitrogen-containing vinyl monomer, and 0-12 parts by weight of vinyl carboxylic acid, said t copolymer being intimately blended with 2-35 percent by weight of plasticizer based on said copolymer, the adhesive being characterized by having a 180 peel adhesion to plasticized vinyl cable jacketing of at least 48 N/dm after being adhered thereto for three days at room temperature, and at least 31 N/dm arter being adhered thereto for one week at 70 0 C.
2. The adhesive of claim 1 wherein the acrylic o 0o* acid ester is isooctyl acrylate. 00
3. The adhesive of claim 2 wherein the nitrogen-containing vinyl polymer is N-vinyl pyrrolidone. 0000 00°00 ooo0 oo 4. The adhesive of claim 2 wherein the Initrogen-containing vinyl polymer is 0 00 N,N-dimethylacrylamide. The adhesive of claim 2 wherein the SI nitrogen-containing vinyl monomer is N,N-pentamethylene i t acrylamide. S6. The adhesive of claim 3, 4, or 5 wherein the Splasticizer is monomeric.
7. The adhesive of claim 6 wherein 2-10 parts of plasticizer are employed. i i li-- i- -,IJ I r- I I I' L i i Rn~l~Xjt
8. A normally tacky and pressure-sensitive adhesive tape comprising a layer of the adhesive of claim 3 carried by a sheet backing.
9. The tape of claim 8 wherein the backing is the back surface of a strip of hook-and-loop fastener material. The tape of claim 8 wherein the adhesive contains microbubbles. 0 a o 00 0 on o o o o 0 0 0 0 0 o0 0 0000 on Go 0 0 0 0 0o 0 0 0 DATED this TWENTY-NINTH day of NOVEMBER 1990 Minnesota Mining and Manufacturing Company Patent Attorneys for the Applicant Spruson Ferguson 0 0 0 0000 o 0 0000 0 0 0 00 0 0 0 0 0 oo0 e 0 0 0 0000 o0 0 00 0 0 00 it i AIT n-z l.j _i.
AU33034/89A 1988-05-20 1989-04-14 Pressure-sensitive adhesive having improved adhesion to plasticized vinyl substrates Ceased AU607603B2 (en)
US07/196,441 US4946742A (en) 1988-05-20 1988-05-20 Pressure-sensitive adhesive having improved adhesion to plasticized vinyl substrates
US196441 1988-05-20
AU3303489A AU3303489A (en) 1989-11-23
AU607603B2 true AU607603B2 (en) 1991-03-07
AU33034/89A Ceased AU607603B2 (en) 1988-05-20 1989-04-14 Pressure-sensitive adhesive having improved adhesion to plasticized vinyl substrates
AR (1) AR247754A1 (en)
AU (1) AU607603B2 (en)
BR (1) BR8902309A (en)
MX (1) MX165998B (en)
ZA (1) ZA8903784B (en)
AU636209B2 (en) * 1990-04-20 1993-04-22 Minnesota Mining And Manufacturing Company Pressure sensitive adhesive comprising solid tacky microspheres and macrospheres and macromonomer-containing binder copolymer
MX9800683A (en) * 1995-07-26 1998-04-30 Minnesota Mining & Mfg Pressure sensitive adhesive patch.
JP4276125B2 (en) 2004-04-27 2009-06-10 日東電工株式会社 Method for producing a medical non-crosslinked pressure-sensitive adhesive and medical adhesive material using the same, and a medical non-crosslinked pressure-sensitive adhesive
JP2016188282A (en) * 2015-03-30 2016-11-04 日本合成化学工業株式会社 Acrylic adhesive for sticking plasticizer-containing member, and adhesive tape
GB8402176D0 (en) * 1984-01-27 1984-02-29 Connell R & I Ltd Adhesive tapes
JPH0124429B2 (en) * 1984-05-22 1989-05-11 Nitsuto Denko Kk
1988-05-20 US US07/196,441 patent/US4946742A/en not_active Expired - Fee Related
1989-04-14 AU AU33034/89A patent/AU607603B2/en not_active Ceased
1989-04-20 CA CA000597245A patent/CA1338367C/en not_active Expired - Fee Related
1989-04-28 DE DE68923400T patent/DE68923400T2/en not_active Expired - Lifetime
1989-04-28 DE DE68923400A patent/DE68923400D1/en not_active Expired - Lifetime
1989-04-28 EP EP89304323A patent/EP0342811B1/en not_active Expired - Lifetime
1989-04-28 ES ES89304323T patent/ES2074076T3/en not_active Expired - Lifetime
1989-05-03 MX MX015905A patent/MX165998B/en unknown
1989-05-17 BR BR898902309A patent/BR8902309A/en not_active IP Right Cessation
1989-05-18 JP JP1125484A patent/JPH0218486A/en active Pending
1989-05-19 ZA ZA893784A patent/ZA8903784B/en unknown
1989-05-19 AR AR89313974A patent/AR247754A1/en active
1989-05-19 KR KR89006678A patent/KR0136868B1/en not_active IP Right Cessation
AU3303489A (en) 1989-11-23
US4946742A (en) 1990-08-07
ES2074076T3 (en) 1995-09-01
EP0342811A3 (en) 1991-09-04
EP0342811B1 (en) 1995-07-12
MX165998B (en) 1992-12-15
CA1338367C (en) 1996-06-04
AR247754A1 (en) 1995-03-31
ZA8903784B (en) 1991-01-30
DE68923400T2 (en) 1996-03-21
BR8902309A (en) 1990-01-09
DE68923400D1 (en) 1995-08-17
EP0342811A2 (en) 1989-11-23
JPH0218486A (en) 1990-01-22
KR0136868B1 (en) 1998-04-25