AU622401B2 - Laminated board and electron beam curable composition used in manufacture thereof - Google Patents

Description

I i -r i 1~"x "u-l II AU-AI-14866/88 WORLD INTELLECTUAL PROPERTY ORGANIZATION International Bureau Is4

PCT

INTERNATIONAL APPLICATION P LI (51) International Patent Classification 4 B32B 21/06, 31/12, C08L 51/08 C09D 3/80, C08F 2/54 T COOPERATION TREATY (PCT) 9j rnaigal Pullication Number: International Publication Date: 22 S WO 88/ 06973 September 1988 (22.09.88) (21) International Application Number: PCT/AUS8/00063 (22) International Filing Date: 9 March 1988 (09.03.88) (31) Priority Application Number: (32) Priority Date: (33) Priority Country: PI 0745 9 March 1987 (09.03.87)

AU

SE (European patent), US.

Published With international search report.

N-.|i 88 S PATENT OFFICE N ovg~gatms~j^^ 1 (71) SECTICtN 34(4)(a) DT)''IICW SEE 1=EIO NAME DIRECiED cLCU4CuE P'Th\ LimiTEt ?C\WELL- RON&) 60,601-,\JAG Rc ,q 3 (81) Designated States: AT (European patent), AU, BE (European patent), CH (European patent), DE (European patent), FR (European patent), GB (European patent), IT (European patent), JP, LU (European patent), NL (European patent), (54) Title: LAMINATED BOARD AND ELECTRON BEAM

TURETHEREOF

CURABLE COMPOSITION USED IN MANUFAC- (57) Abstract A composite board provided with a decorative or protective surface is manufactured by coating an electron beam (EB) curable pigmented composition onto a carrier sheet, curing the composition by EB irradiation and then bonding the cured coated carrier to the board. The carrier is preferably a paper selected for high opacity. The coating composition preferably comprises acrylate oligomers and one or more acrylate monomers having a viscosity desirably greater than 1000 cps at 20 0 C applied to result in coating weights less than 15 gsm. A coating composition and a coated paper are also claimed.

i i ii .WO.88/06973 PCT/AU88/00063 -1- LAMINATED BOARD AND ELECTRON BEAM CURABLE COMPOSITION USED IN MANUFACTURE THEREOF Field of the Invention This invention relates to a method for manufacture of a composite board having a decorative or protective laminated surface and to laminates for use with the method.

The invention is herein described with particular reference to laminates in which the composite board is particle board but it will be understood that the method of the invention can usefully be applied to other substrates, for example chipboard, hardboard, reformed hardboard and the like.

Background of the Invention Composite boards manufactured by bonding together particles or chips of wood are widely used in building and construction and for the manufacture of furniture.

It is often desired to provide such board or other composites with a factory applied decorative or protective finish and that has hitherto been accomplished by laminating a thermosetting resin sheet, for example a melamine sheet, under pressure, to a surface of the board or by painting the board surface i i WO 88/06973 PCT/AU88/00063 -2with a conventional air-dried or solvent based paint.

When laminated particle board is intended for use in kitchens, bathrooms or the like the exposed surface is frequently subjected to harsh treatment including cleaning and scrubbing, often with abrasives and sometimes with solvent preparations. The decorative surface is thus required to have a high order of hardness, scuff resistance, water and solvent resistance.

Melamine laminated surfaces provide an excellent hard, scuff-resistant decorative surface but stacked sheets of melamine are expensive to handle and the process of laminating individual stiff sheets to respective boards using heated presses is labour intensive and too costly for many end uses.

Paint systems now in use for factory finishing hardboards and particle boards while less expensive to apply have less satisfactory properties than melamine laminates and tend to be more costly than is desired.

The drying step of the painting process is especially costly in terms of space requirement. When applied to timber the paints tend to raise the grain requiring sanding between multiple coats. The unevenness of hardboard surfaces also necessitates application of multiple coats or fillers, adding to materials cost.

In an effort to more rapidly dry the paints, it has been proposed to cure paints applied to such substrates by UV radiation. The faster curing obtainable with UV -3curing reduces space requirement to some extentz but IJV-cureable formulations are limited in pigment loading capacity and are restrictedi in their ability to accept pigments of certain colours.

An object of the present invention is to provide a composite board having a surface finish which has a satisfactory level of hardness, scuff resistance and solvent resistance and which can be produced more economically than conventional melamine laminates.

A further objective is to provide a surface finish C Cto hardboard which has a desired opacity (so as to be able to hide joins or defects in the substrate) and which provides the necessary gloss and chemical resistance.

Disclosur e of Invention According to one aspect, the invention consists in a method for manufacture of a composite board having a decorative or protective surface, comprising the steps of: a) coating an electron beam curable pigmented composition onto a carrier sheet; b) curing the composition by means including electron see abeam irradiation; bonding the cured coated carrier sheet to a composite board; d) winding the carrier sheet obtained from the curing step onto a roll; and e) feeding the carrier from the roll prior to or during the bonding step.

It has been found that compositions may be prepared whc4cethg;laig fpget mr hn4%b whc cethg laig fpget mr hn4%b WO 88/06973 PCT/AU88/00063 4 weight) and which may nevertheless be cured by electron beam radiation at high speeds 400 m/min.) after coating onto a relatively inexpensive carrier sheet such as paper.

Surprisingly, it has been found that selected EB curable compositions are sufficiently flexible to be wound onto a roll at high EB curing speeds and yet when subsequently laminated to particle board, provide satisfactory hardness, water and solvent resistance. It is usual that cured polymer films which exhibit flexibility do so at the expense of hardness and solvent resistance.

In highly preferred embodiments, the carrier sheet is a paper.selected to have an intrinsic opacity S/Yw >0.9 when measured on the MINOLTA chromometer and the cured coating is applied at less than 15 gsm.

Desirably the coating composition has a viscosity greater than 1000 cps at 30 0 C and is applied at an elevated temperature, e.g. 40 50 0 C or up to 60 0 C, the application viscosity being about 3 400 cps at the application temperature.

In preferred embodiments, the method is economically competitive with other laminated composite boards produced by the prior art methods.

Preferred embodiments of the invention Various embodiments of the invention will now be described, by way of example only.

"i WO 88/06973 PCT/AU88/00063 In general, the first step in methods according to the invention is to coat a carrier, for example paper or foil, with an EB curable composition. For preference, the carrier is a paper having low oil absorption characteristics in order to minimize penetration of the curable composition during the dwell time between coating and curing.

In order to achieve an opacity in the cured coated paper which will adequately hide the substrate, it is important to select a paper having an intrinsic opacity Yb/Yw>0.9 (Brightness Opacity herein expressed as Yb/Y refers to measurements in the YXY system as determined with a MINOLTA chromometer.

A paper of opacity Yb/Y w>0.9, when coated and cured according to the invention, will have an intrinsic opacity >0.95 (Brightness >90) and will hide the substrate at surprisingly low coating weights of less than 15 gsm and usually 4 10 gsm depending on pigment loading in the coating.

It is also desirable to select a paper which has the ability to "hold out" the wet coating such that gloss is maximized and transparency is minimized.

The best papers have been found to be 60 gsm approximately and (usually) clay coated both sides. One Trade Mark of APPM j 1 WO 88/06973 PCT/AU88/00063 -6suitable example is Austral Cote* 63gsm ex APPM with intrinsic opacity Yb/Yw>0.

91 (brightness 86). When coated with 10 gsm of example H, this opacity rises to 0.98 (brightness 92). In addition a gloss level of 55 is achievable using this paper.

SAnother important factor in selection of paper for use in the invention is the presence of lignins and wood.

Papers made from pulp which has not been chemically treated mechanically ground wood pulp or semi-chemical pulp from which lignin has not been removed) are favoured.

It is believed that the presence of lignins in the paper reduces the tendency for the paper to appear translucent when a clear coating is absorbed into the paper causing a refractive index reduction. That tendency may be minimized by selecting papers containing less then 20% of wood free or chemical pulp.

However, in less preferred embodiments the coating may be applied to foils, cellulose fibre batts, webs, felts or other carriers which may be bonded to a composite board.

The EB coating composition comprises one or more cross-linkable acrylate oligomers. For preference, the.

oligomer is selected from the group consisting of urethane acrylate, epoxy acrylate, polyester acrylate and silicone acrylate oligomers.

These oligomers may be multifunctional,

S

.4 r WO 88/06973 PCT/AU88/00063 7 self-crosslinking oligomers or may be used in combination with crosslinking agents. Preferred crosslinking agents are acrylate monomers and more preferably ether acrylate monomers or alkoxylated acrylate monomers, e.g. tripropylene glycol diacrylate.

The EB curable composition essentially includes one or more pigments and optionally may include filters, extenders, dyes, and other additives.

The selection of oligomer influences flexibility, hardness, abrasion and solvent resistance of the end product and pigmentability.

Table I shows the viscosity of various compositions identified by characters to Of these, compositions to inclusive are embodiments of the invention and compositions to are included for comparison only.

With reference to formulations and of Table 1, EBECRYL* 1810 is a low viscosity polyester acrylate having an "as supplied" viscosity of 340 cps with no diluent added. This has been found to provide an excellent grinding medium for pigments and enables a pigment loading of up to 71% w/w without addition of diluent. After EB curing formulation and a hard and glossy film is obtained from each. In Trade Mark of UCB Trade Mark of Polycure Pty. Ltd.

~L WO 88/06973 PCT/AU88/00063 comparison with formulation it is difficult to achieve pigment loadings in excess of 60% in URACRIL** T (an aromatic trifunctional urethane acrylate) without addition of a diluent. The films produced on curing formulation are duller, have lower solvent resistance and are more easily scuffed.

Formulation utilizes a low molecular weight, highly reactive aromatic urethane triacrylate (LOCRIL** 3134) in which pigment loadings of 60% may be satisfactorily achieved without the use of diluent and on curing hard, glossy and very solvent resistant coatings are obtained.

When thinned with monomer (TPGDA), the LOCRIL 3134 system has superior solvent resistance, hardness and water resistance at identical viscosity to the EBECRYL 1810 system and has very similar gloss. In practice, pigment loadings of 60% represent a practical maximum above which additional pigment does not substantially increase opacity.

By utilizing high pigment loadings, the opacity of the film is such that surprisingly thin films may be I utilized. For example, formulation may be used in filmr as thin as 6 7 grams per square meter (gsm).

In flexibility, comparable coatings of the three oligomers ranked URACRIL T EBECRYL 1810 LOCRIL 3134. The oligomers rank in the reverse order in respect of hardness and solvent resistance, LOCRIL 3134 WO 88/06973 PCT/AU88/00063 9 being the hardest and most solvent resistant.

If molecular weight of the oligomer is too low, the composition tends to "soak in" excessively prior to curing, while if the molecular weight is too great, it is difficult to obtain satisfactory pigment loading.

Oligomer molecular weights in the range of from 1000 to 4000 or more have been found to be particularly suitable.

Although some oligomers such as EBECRYL 1810 may be cured by electron beam (EB) irradiation without additional crosslinking agents (see formulation compositions according to the invention desirably comprise a crosslinking agent which is preferably one or a blend of monomers, and more preferably is a blend of multifunctional ether acrylate, or alkoxy acrylate, monomers. Particularly suitable acrylate monomers include: Tripropylene glycol Diacrylate "TPGDA" Propoxylated Glycerol Triacrylate "PGTA" Dipropylene Glycol Diacrylate "DPGDA" Hexanedioldiacrylate "HDDA" These monomers are compatible with the oligomer system and are efficient viscosity reducers. They have low odour, high crosslinking efficiency (and thus provide high cure speed) and low DRAIZE value (skin irritancy).

In a preferred embodiment a blend of TPGDA:DPGDA:PGTA is employed with URACRIL T as 3-P

'A

WO 88/06973 PCT/AU88/00063.

10 the oligomer.

In another embodiment a 60:40 blend of TPGDA/PGTA is used with URACRIL T.

Increasing the level of the trifunctional monomer substantially increases solvent resistance in the finished product.

It has been found to be desirable to include a wetting agent such as NUOSPERSE 657. However, levels in excess of about 0.5% are likely to adversely affect solvent resistance.

Water resistance is of particular importance for laminates for use e.g. inside kitchen cupboards. Water resistance can be measured by two different but related parameters, namely water absorption into the paper laminate, and water transmission into the laminate substrate.

Water resistance is important to prevent delamination and substrate swelling. We have found that water resistance decreases in the order LOCRIL 3134 URACRIL T EBECRYL 1810 but is enhanced by heavier film i weights and by inclusion of hydrophobic monomers e.g.

I HDDA, TMPTA. Water resistance is also improved by Scluding a silicone diacrylate such as EB 350 (available from UCB) in the oligomer blend. In general, it is preferable to select those compositions which include oligomers having the highest crosslinking density and the greatest hydrophobicity e.g. urethane '1 WO 88/06973 PCT/AU88/00063 11 acrylates with alk-y, -kbones and with high functionality.

The coating formulation may be applied to the paper by any suitable means for example by use of a roller coater at elevated temperature, for example 45 0 C by knife coaters or by other means.

The applied coating is cured by an electron beam.

Curing is typically conducted at speeds of 400 m/min.

with a dose of 3 M rads in the presence of an inert

(N

2 atmosphere. Under these conditions (400 m/min) the dwell time of the composition between coating and curing is about 0.3 seconds. Cured coatings of 1 gsm give adequate opacity when paints of 40 pigment loading are used depending on choice of paper.

The cured coated sheet or foil so produced is sufficiently flexible to be wound onto a roll in long lengths at 400 m/min and may be economically produced and stored on the roll.

The cured coated sheet or foil is subsequently unwound from the roll and laminated onto a composite board, particularly hardboard, particle board or other substrate.

The laminating process varies slightly depending on the adhesive but is essentially application of adhesive to the substrate by roller coater followed by IR heating and application of the laminating foil to the substrate via a modified roller coater set up to apply the WO 88/06973 PCT/AU88/00063 12 appropriate laminating pressure. Typical temperatures after IR heating are 80°C and typical operating speeds are 30 m/minute. Ease of application of adhesives is PVA>EVA>U-F (higher laminating temperatures are required in the same order).

If desired, offcuts of hardboard or particle board may be glued together in a continuous edge-to-edge assembly and the coated paper may be laminated to the surface, the opacity of the paper being sufficient to mask the underlying joints.

The "coated and cured" paper does not have the hardness or abrasion resistance of a high pressure melamine resin lamination sheet but performs very well in comparison with prior art paints in respect of scuff resistance, abrasion resistance and resistance to common household solvents and water.

On the other hand, laminated board made according to the invention is inexpensive to manufacture in Comparison with prior art laminates utilizing melamine sheets. Advantageously, coated and cured paper as described herein is sufficiently flexible for handling in rolls, and thus is able to be laminated to a chip board substrate on a continuous basis and at comparatively low production costs.

Electron beam dose, dose rate and curing speed may be varied to an extent which can be determined'by routine experiment. Dual cure systems in which EB

'I

L- WO 88/06973 PCT/AU88/00063 13 curing is combined with UV, or with vapour catalyzed or isocyanate curing systems or the like may be employed, As will be apparent to those skilled in the art from the teaching hereof, the invention may he embodied in other forms and the coating compositions may be varied from those described to an extent which is determinable by routine experiment, Modifiers such as gloss or matt additives, viscosity control agents, extenders, fillers and catalysts and the like may be added without departing from the invention herein disclosed.

i

I

WO 88/06973 PCT/AU88/ 00063 14 TABLE I A B C D E F G H I J 'Uracril T 100 34 22 22 Locril 31342 100 34 18 EB1810 100 34 29 'Nuosperse 657(4) 0.5 0.5 0.5 0.5 0.3 0.3 TPGDA 21 21 26 9 33 26 TIONA 464 45 45 40 71 44 44 DPGDA 17 PGTA 7 Anti-settling(9) 0.7 0.7 viscosity cps 13K 13K 340 1,4K 1,1K-'85 23K 1.1K 1,1K 0.9K Solvent D/R (logsrn) 8 1 18 15 5 Aromatic trifunctional urethane acrylate ex Polycure, containing 30% TPGDA, Double bond EW=532.

Aromatic trifunctional urethane acrylate ex Polycure, containing 30% TPGDA, Double bond EW=357.

Low viscosity Polyester acrylate ex UCB.

Wetting agent ex A.C. Hatricks.

Tripropylene glycol diacrylate ex UCB, Rutile titanium dioxide ex SCM.

Dipropyleneglycoldiacrylate ex Degussa.

Propoxylated glyceroltriacrylate ex Synthese.

Claims (23)

1. A method for manufacture of a composite board having a decorative or protective surface, comprising the steps of: a) coating an electron beam curable pigmented composition onto a carrier sheet; b) curing the composition by means including electron beam irradiation; c) bonding the cured coated carrier to a composite 4 board; S winding the carrier sheet obtained from the curing I step onto a roll; and e) feeding the carrier from the roll prior to or during the bonding step.

2. A method according to Claim 1 wherein the electron beam curable composition includes one or more oligomers S, selected from the group consisting of urethane acrylates, polyester acrylates, epoxy acrylates and S' silicone acrylates and at least one pigment.

3. A method according to Claim 2 wherein the electron beam curable composition includes at least one acrylic monomer. c

4. A method according to Claim 3 wherein the acrylic monomer is selected from the group consisting of polyfunctional acrylate monomers.

A method according to Claim 4 wherein the selected monomer is a polyfunctional alkoxy or ether acrylate monomer. /r\ 16

6. A method according to any one of the preceding claims wherein the carrier sheet is paper.

7. A method according to Claim 6 wherein the paper has an opacity Yb/Y >0. 9 when measured on a MINOLTA chromometer.

8. A method according to any one of the preceding claims wherein the electron beam curable coating composition is applied at from 1 15 gsm to the carrier sheet.

9. A method according to any one of the preceding claims wherein the selected oligomer is predominantly a urethane acrylate.

A method according to Claim 9 wherein the oligomer is an aromatic trifunctional urethane acrylate.

11. A method according to any one of the preceding claims further comprising the step of disposing a plurality of composite board pieces into an assembly in which the faces of the pieces are co-planar, and in b which an edge of one piece abuts an edge of an adjacent S q •piece, and bonding the carrier obtained from step to S e' the co-planar faces of the pieces in the assembly.

12. A laminate comprising a composite board, a flexible lamina bonded on at least one side of the board, the lamina being a carrier sheet having less than 15 gsm of an opaque, pigmented, electron beam cured coating composition on its exposed surface.

13. A laminate according to Claim 12 wherein l L a I0 17 the carrier sheet is paper.

14. A laminate according to Claim 13 wherein the paper has an opacity Yb/Yw>0. 9 when measured on a MINOLTA chromometer.

A method according to any one of claims 1 to 11 wherein said curable pigmented composition comprises from 18 to 34% by weight of an acrylate oligomer.

16. A method according to claim 15 wherein the said curable pigmented composition comprises from 1 to 33% by weight of an acrylate monomer or monomers. ee

17. A method according to claim 16 wherein the said curable pigmented composition comprises from 40 to 71% by weight of pigment. 1*

18. A method according to claim 16 when the acrylate monomer comprises a tripropylene glycol diacrylate.

19. A method according to claim 15 substantially as herein described with reference to any one of examples to J.

20. A sheet suitable for use in steps and of a .method according to Claim 1, the sheet comprising a paper having an opacity Yb/Yw> 0 9 when measured with a MINOLTA chromometer, the paper being coated with a pigmented, electron beam cured composition and having a coated weight of less than 15 gsm.

21. A sheet according to Claim 20 having an opacity Y/Y w>0.95 in the cured coated product.

22. A laminate when made by a method of any one of Lt6 I 4 ,xo, nP_ 18 claims 1 to 11 or claims 15 to 19.

23. A laminate comprising a composite board having a sheet according to any one of claims 20 to 22 bonded on at least one side of the board. DATED this Thirty-first day of January 1992 POYLCURE PTY. LTD. Attorney: IAN T. ERNST Fellow Institute of Patent Attorneys of Australia of SHELSTON WATERS i[[ .e 1 19 ABSTRACT A composite board provided with a decorative or protective surface is manufactured by coating an electron beam (EB) curable pigmented composition onto a carrier sheet, curing the composition by EB irradiation and then bonding the cured coated carrier to the board. The carrier is preferably a paper selected for high opacity. The coating composition preferably comprises acrylate oligomers and one or more acrylate monomers having a viscosity desirably greater than 1000 cps at 20°C applied to result in coating weights less than .gsm. *o *e 1 r "-4 c I INTERNATIONAL SEARCH REPORT International Application No PCT/AU88/00063 I. CLASSIFICATION OF SUBJECT MATTER (it several classification symbols apply, indicate all) According to International Patent Classification (IPC) or to both National Classification and IPC Int. Cl. B32B 21/06, 31/12, C08L 51/08, CO9D 3/80, C08F 2/54 II. FIELDS SEARCHED Minimum Documentation Searched 7 Classification System Classification Symbols IPC B32B 21/06, 31/12, C08L 51/08, C08F 2/54 Documentation rearched other than Minimum Documentation to the Extent that suc;. Documents are Included In the Fields Searched AU: IPC as above; Australian Classification 79.3 Ill. DOCUMENTS CONSIDERED TO BI RELEVANT' Category Citation of Document, it with indication, where appropriate, of the relevant passages 12 Relevant to Claim No. 1_ X CH,A, 560729 (CIBA-GEIGY AG) (1,2,7-9,13-16) April 1975 (15.04.75). See claims and column 1 and column 2 li.nes 37-41. A EP,A, 107608 (THE GOODYEAR TIRE RUBBER COMPANY) (16, 17) 2 May 1984 (02.05.84). X US,A, 4364971 (SACK) 21 December 1982 (21.12.82) (16) See examples 2, 4 and A AU,A, 21851/67 (FORD MOTOR COMPANY OF CANADA LIMITED) (16) 21 November 1968 (21.11.68). See page 2 line 29 to page 4 line 4. A AU,B, 30181/67 (423759) (FORD MOTOR COMPANY OF (16) CANADA LIMITED) 29 May 1967 (29.05.67). See page 2 line 15 to page 3, line 4. A AU,B, 68945/74 (487895) (UCB, 20 November 1975 (16) (20.11.75). See claims 1 and (continued...... SSpecial categoriex of cited documents: to later document published after the international filing date nt dining t genera s r or priority date and not in conflict with ths application but document defining the general state of the art which Is not cited to understand the principle or theory underlying the considered to be of particular relevance invention earlier document but published on or after the International document of particular relevance; the claimed invention filing date cannot be considered novel or cannot be considered to document which may throw doubts on priority claim(s) or involve an inventive step which is cited to establish the publication date of another document of particular relevance; the claimed Invention citation or other special reason (as specified) cannot be considered to involve an inventive step when the document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docu- other means ments, such combination being obvious to a person skilled In the art. document published prior to the international filing date but In te later than the priority date claimed I" document member of the same patent tfmlly IV. CERTIFICATION Date of the Actual Completion of the International Search 21 June 1988 (21.06.88) Date of Mailing of this International Search Report Z.7 9 International Searching Authority AUSTRALIAN PATENT OFFICE Signature of Authorized Officer D.J. SHEPHERD Form PCTISA20 (second shet) (Jau 1 Form PCT/tSA/210 !second shH (January 1985) I 7 International Application No. FCT/AU88/00063 FURTHER INFORMATION CONTINUED FROM THE SECOND SHEET AU,B,44661/79 (521663) (THICIML CORP.) 22 April 1982 (22.04.82) See Exanple 14 AU,A,63036/86 (FMECHST AG) 26 March 1987 (26.03.87) (16) (1,16) OB] 8SERVATIONS WHERE CERTAIN CLAIMS WERE FOUND UNSEARCHABLE'i This International search report has not been established In respect of certain claims under Artile 17(2) for the following reasons. 17 Claim numbers because they relate to subject matter not required to be searched by this Authority, namely: Claim numbers because they relate to parts of the International application that do not comply with the prescribed require-' ments to such an extent that no meaningtul international search can be carried out, speocificaily: 3]Claim numbeors beus they .e depisident claims a" are not drafted In accordance Vith the, second ardthird senterims of PCT Rule, 6.4(s). V.Z] OBSERVATIONS WHIERE UNITY OF INVIENTION IS LACKING 2 This International Searchlorg Authority found multiple Inventions In this International application as follows: Claimns 1 to 15: A laminate and method of manufacture Claims 16 to 19; A coating ccnposition Claim 21 arid 22: A coated paper As all required additional search fees were timely paid by the applicant, this fntrrnational search report covers all searchable claims of the International application. 24KM As oniy some of the required additiorlal search fees were timely paid by the vtppllcant, this Interniational search report covers only those clims of the International application for which fae wefe paid, speciflcaliy clis: 1 to 19 3.7 No required additional search fees were timely paid by the spplicant. Consequently, this International search report Is restricted to the Invention first mentioned In the claims; it ls covered by claim numbers:. 4..As all searchable claims could be searched without effort justifying an additional fee, the International Searching Authority did not *Invite payment of any additional fee, Remark on Protest EJ The additional search fees were accompanied by applicant's protest. 21to protest accompanied the payment of additional search fees. Form PCTIISA/210 (supplemental sheet (January 1985) 9I- ANNEX TO THE IERNATIONAL SEARCH REPORT ON INTERNLTIONAL APPLICATION NO. PCI'/AU 88/00063 This Annex lists the known publication level patent family members relating to the patent documents cited in the alzove-mentioned international search report. The Australian Patent Office is in no way liable for these particulars which are merely given for the purpose of information, Patent Document Cited in Search Patent Family Mmbers Report EP 107608 BR 8304836 JP 59066413 US 4364971 BE 888705 CH 648135 DE 3022709 FR 2485217 GB 2078236 JP 57030830 AU 68945/74 AT 3962/74 BE 814979 BR 7403915 CA 1030979 CH 591417 DE 2423354 DK 3793/75 ES 426283 FR 2237875 FR 2264831 GB 1461597 IL 44822 IT 1013159 JP 50052020 4 JP 56152818 LU 70074 NE 1 7406326 NO 752955 US 3952032 US 4082710 AU 44661/79 AT 2095/79 BR 7901725 CA 1145100 DK 1128/79 EP 4362 IT 1114951 J1P 54130514 US 4182790 ZA 7900799 AU 63036/86 DE 3533737 NO 863746 EP 216269 JP 62099147 END OF ANNEX 23/87.1" 1,'2