EP0695223A4

EP0695223A4 - Heat reactivatable adhesive

Info

Publication number: EP0695223A4
Application number: EP95909229A
Authority: EP
Inventors: Glenn R Magrum; Jack A Stover
Original assignee: Ashland Oil Inc
Current assignee: Ashland LLC
Priority date: 1994-01-12
Filing date: 1995-01-11
Publication date: 1997-12-10
Also published as: EP0695223A1; WO1995019231A1; AU1726095A

Abstract

This invention is a method of using a heat activatable adhesive for laminating vinyl sheet to wood. The solvent-free adhesive combines a reactive styrene-acrylic latex emulsion and an ethylene-vinylacetate copolymer. After application to the vinyl substrate the adhesive is heat activated at temperatures as low as 160 °F (71 °C) and the laminate resists 200 °F (93 °C).

Description

HEAT REACTIVATABLE ADHESIVE This invention relates to water-based adhesives for bladder pressing, vacuum pressing and laminating vinyl to wood substrates. BACKGROUND OF THE INVENTION

A variety of adhesives have been developed for use in laminating wood substrates and in laminating wood substrates to vinyl substrates. Among the wood laminating adhesives is that described in U.S. Patent

3931088 Kuraray which combines an isocyanate polymer in solvent with aqueous polyvinyl alcohol, aqueous vinyl acetate, or aqueous butadiene polymer. This adhesive provides excellent bonding in wood-to-wood applications. However, in specialty applications where a flexible substrate such as plastic sheeting or film is bonded to wood, the degree of adhesiveness at the plastic interface exhibited by such compositions is less than desired.

U.S. Patent 4,396,738 Ashland describes a wood-to-wood adhesive made with a vinyl polymer and a partially reacted polyisocyanate. U.S. Patent 4,433,095 Bayer describes a wood-to-wood adhesive made from aromatic isocyanate and an emulsifier made from isocyanate and alcohol.

U.S. Patent 4,491 ,646 Ashland describes a wood-to-wood adhesive which combines an aqueous hydroxyl functional acrylic latex containing hydroxyl groups as its only isocyanate reactive functionality and a multi- isocyanate crosslinking agent.

U.S. Patent 4,609,690 Ashland describes a wood laminating adhesive curable at room temperature which combines an aqueous hydroxyl-functional acrylic latex with emulsified multi-isocyanate crosslinking agent. None of these wood-to-wood adhesives makes very strong bonds when used to adhere vinyl substrates to wood substrates. They also suffer from the drawback of having very short pot-lives. Various adhesives especially designed for adhering wood to vinyl have been developed. Because vinyl softens at temperatures around 200°F, these vinyl to wood adhesives must activate or cure below 200°F, they must however be able to withstand high temperatures because the adhered substrates are used in hot kitchens, mobile homes, and automobile interiors where temperatures may climb above 200°F for short time periods. European Patent Application 367120 Air Products describes a water- based adhesive for laminating vinyl substrates to wood which consists essentially of vinyl acetate-ethylene emulsion copolymer and water dispersible polyisocyanate, has a pot life of 6 hours and passes a heat and creep resistant test at 170°F. European Patent Application 444259 Bayer describes a laminating adhesive for PVC or PVC foam and ABS made of polyurethane dispersions forming films below 70°C, copolymers of a,b-unsaturated monomers such as styrene having a softening point above 70°C, and, optionally, dispersible reactive aliphatic polyisocyanate. U.S. patent 4,618,390 Ashland describes an adhesive for bonding a vinyl substrate to a rigid wood substrate. The adhesive is an aqueous emulsion of butylacrylate-methylmethacrylate-2 hydroxyethyl acrylate terpolymer, polypropylene glycol and polyisocyanate having a pot life of at least one hour. This adhesive is applied by roll coater to one substrate, the second vinyl substrate is applied immediately. The manufacturer of wood- vinyl laminates uses the bonding adhesive directly and must see that coating equipment spreads the liquid adhesive evenly and completely.

It would be desirable to have an adhesive which is applied, not at the facility where the vinyl is laminated to the wood substrate, but at another location where the adhesive is applied to the vinyl substrate, dried, and then at a convenient later date, is heat activated. The laminator would then simply apply the coated vinyl to the wood using heat and pressure to activate the adhesive and avoid all complications of applying liquid adhesive. The laminated vinyl-adhesive-wood product should withstand environments hotter than 200°F.

OBJECT OF THE INVENTION

It is therefore an object of this invention to develop a strong water-based adhesive which is applied to vinyl substrate, dried, then heat activated at temperatures as low as 150°F to join vinyl to wood substrates forming a strong bond which will withstand exposure to temperatures as high as 250°F.

SUMMARY OF THE INVENTION

This invention is a method of using a heat-activatable adhesive for laminating vinyl sheet to wood substrates. This solvent-free adhesive combines a reactive styrene-acrylic latex emulsion and an ethylene vinyl acetate copolymer emulsion; both having certain glass transition temperatures (Tg) as measured by ASTME 1356. Optionally, one or more of itaconic acid, glyoxal, zinc acetyl acetonate catalyst, and a stable nonreactive aliphatic water-based polyurethane dispersion, also having a specific Tg, may be added. After applying the adhesive on the vinyl, the adhesive is dried, the coated vinyl is rolled and shipped to the customer. The customer forms or laminates the adhesive coated vinyl on to the customer's wood substrate and the adhesive is heat activated at temperatures of 160°F or 170°F depending on the combination of ingredients in the adhesive. After lamination to a wood substrate the laminate resists temperatures greater than 200°F. DESCRIPTION OF THE PREFERRED EMBODIMENTS

Vinyl films which can be used in the present invention include cast, calendered and extruded vinyl films. Suitable vinyl films, include polyvinyl chloride, copolymers of vinyl chloride, such as vinyl chloride-vinyl acetate copolymers, polyvinyl fluoride, polyvinyl formal, polyvinylidene chloride, polyvinyl butyral, polyvinylidene fluoride, and the like. The preferred vinyl film for use in the present invention is a polyvinyl chloride film. Vinyl films of any thickness between 4 and 30 mils may be used in the present invention. It is not necessary to use a primer on vinyl substrates when the "primerless" adhesive of this invention is used. Among other useful flexible substrates are paper and cloth. Suitable substrates for lamination with the adhesive of this invention may be fibrous, non-fibrous, porous and non-porous, metallic and non-metallic, polymeric, leather, cork, wood and glass. The preferred rigid substrate in the practice of this invention is particle board. The first ingredient of the adhesive of this invention is a reactive styrene-acrylic latex emulsion. This emulsion can be made from acrylic acid, methyl methacrylate, styrene, hydroxy ethyl acrylate, butyl acrylate polymer, water and ethyl acrylate. The pH may be 6.5 to 8. Useful reactive styrene- acrylic latex emulsions include: Rohm & Haas 76 RES 1026 emulsion -32°C Tg ± 6°C

Rohm & Haas Rhoplex P-376 emulsion +21 °C Tg ± 6°C Rohm & Haas 76 RES 1018 emulsion +22°C Tg ± 6°C Rohm & Haas HSB6 emulsion 12°C Tg ± 10°C and 48 ± 10 °C (bimodal) Rohm & Haas 76 RES 1019 emulsion -15°C Tg ± 6°C Rohm & Haas 76 RES 10526 emulsion -32°C Tg ± 6°C

Union Carbide UCAR 462 emulsion 45 ±5°C Tg Union Carbide UCAR 451 emulsion 42 ±5°C Tg The most preferred reactive styrene-acrylic latex emulsion is that having a Tg of 45 ± 6°C for making laminates having the best strength at room temperature. For making laminates having the best strength when tested at temperatures as high as 200°F (93°C) the most preferred styrene acrylic has a bimodal Tg distribution of 12 ± 6°C and 48 ± 6°C.

From 30 to 70 weight percent reactive styrene acrylic emulsion is used in the heat activated vinyl to wood laminating adhesive of this invention. The second ingredient of the adhesive of this invention is an ethylene- vinyl acetate copolymer emulsion having a Tg between -5°C and 10°C such as that available from Rohm and Haas, Philadelphia, Pennsylvania as LAM.2 emulsion (Tg 10± 10°C) or from Air Products, Allentown, Pennsylvania, as Airflex 465 emulsion (Tg -5°C ±3°C). From 30 to 70 weight percent ethylene- vinyl acetate copolymer emulsion is used in the adhesive of this invention.

Optional ingredients for addition to the adhesive of this invention include a stable non-reactive aliphatic water based urethane having an ionic charge such as Q-Thane QW-16 urethane available from K.J. Quinn, Seabrook, New Hampshire, having a Tg -26°C ± 11 °C, a polyether based aliphatic polyurethane. From 16 to 35 weight percent aliphatic water based urethane may be used ^'■■- he adhesive of this invention.

Glyoxal is another optional ingredient. Glyoxal is available from Aldrich Chemical, Milwaukee, Wisconsin. Up to 6 weight percent glyoxal may be used.

Itaconic acid, acrylic acid and methacry c acid are other optional ingredients and are available from Aldrich Chemical. Up to 6 weight percent acid may be used in the adhesive of this invention.

Zinc acetyl acetonate catalyst is a further optional ingredient, 0.01 to 0.5 weight percent may be used in the adhesive of this invention.

In one embodiment this invention is a method of making a heat stable laminate of a flexible substrate and a solid substrate adhered together by the dried residue of a heat activatable 55 to 65 weight percent reactive styrene- acrylic emulsion, 35 to 45 weight percent ethylene-vinylacetate emulsion and 1 to 3 percent itaconic acid.

The adhesive of this invention is prepared by first admixing the urethane and other optional ingredients with the ethylene-vinyl acetate copolymer. To this mixture the styrene-acrylic copolymer is added. These are mixed for 30 minutes. The adhesive can then be used immediately or stored for at least two months without detrimental effects on its bonding capability. If a higher viscosity product is desired, cellulosic and urethane based thickening agents can be added. Silica based products and extenders can also be added at this point.

The adhesive of this invention is used by coating the adhesive by any of a variety of common coating methods onto a vinyl or paper substrate and drying. The coated substrate is then heat reactivated at temperatures greater than 150°F (65°C) and pressed onto the second substrate of choice, which may be wood, steel, glass or foam. Bladder pressing, nip rolling, and vacuum pressing are common methods for accomplishing this. Match metal presses, roller presses and platen presses may also be used.

All references cited herein are hereby expressly incorporated by reference. In order to further illustrate the manner in which the present invention can be implemented, the following working examples are given. All parts and percentages referred to therein are by weight unless otherwise indicated.

The following examples show adhesives of this invention which are activated at 170°F (77°C) and 150 (65°C) or 155°F (68°C). Example 1 170°F Activation

Reported in Table 1 are peel strengths ("PLI" means pounds per linear inch) at room temperature and at 180°F (82°C) of vinyl-wood laminates.

TABLE 1

PRELAM 170 77°C; 2 BAR, 3 MINUTES

ADHESIVE PEEL STRENGTH 82°C PREHEATED I

(PLI)

RT

HSB6 styrene-acrylic 2.11 4.68 1.71

LAM2 ethylene vinyl acetate 2.25 1.19 3.28

LAM2/HSB6¹ 2.35 6.01 1.88

I ^•^1 PRELAM 170, NO CATALYST² 4.05 5.87 1.7

PRELAM 170, NO GLYOXAL³ 5.05 6.81 2

PRELAM 170, NO ITACONIC ACID⁴ 3.33 7.87 1.5

PRELAM 170⁵ 4.81 6.63 1.28

PRELAM 170, NO ITACONIC ACID OR 4.34 7.15 1.32 CATALYST⁶

PRELAM 170, NO GLYOXAL OR 3.44 5.81 1.49 CATALYST⁷

"Preheated" means heated to 71 °C for 3 minutes, cooled, then applied to wood substrate RT is room temperature

Example 1 and Table 1 show that a laminating adhesive activated at 170°F (77°C), strong at room temperature and 180°F (82°C) testing can be made by combining styrene-acrylic latex and ethylene vinyl acetate. Addition of one or more of zinc acetyl acetonate catalyst, glyoxal, or itaconic acid improves the strength of the vinyl to wood bond at room temperature and at 180°F (82°C) testing.

Example 2 describes formulations displaying the ability to be activated

at 160°F (71°C).

Reported in Table 2 are peel strengths at room temperature and 180°F (82°C) of vinyl-wood laminates made using vinyl substrate coated with adhesives and heat activated 160°F (71 °C).

TABLE 2

160°F Activation (71 °C)

2 BAR; 3 MINUTES

ADHESIVE PEEL STRENGTH (PLI) PREHEATED⁸ RT 180°F RT

UCAR 462 styrene-acrylic 0.61 3.28* 1.38

HSB6 styrene-acrylic 0.46 4.68* 1.71

LAM2 ethylene vinyl acetate 0 1.19* 3.28

QW16 aliphatic water based 1.77 2.95 5.59 urethane

I LAM2/QW16_! 1.82 4.18 4..iβ j to

UCAR462/LAM2² 1.65 2.88* 1.72

UCAR 462/QW16³ 1.79 5.47 1.69

LAM2/HSB6² 1.67 6.01* 1.88

PRELAM 160⁴ 5.91 6.04 1.61

PRELAM 160⁵ 4.34 7.25

HSB6/QW16⁶ 1.42 9.88 2.37

"Heated to 160°F (71 °C) in the press at 0.531 A atmospheres, cooled, then laminated at 77°C

Example 2 and Table 2 show that a laminating adhesive activatable at 160°F (71 °C) can be prepared by combining ethylene vinyl acetate, styrene acrylic with Tg 35°C - 48°C and aliphatic water based urethane (footnote 4). An adhesive activatable at 160°F (71 °C) can also be prepared by combining

ethylene vinyl acetate, styrene acrylic with Tg of 42 ± 5°C and aliphatic water based urethane. (footnote 5). Both adhesives are strong at room temperature and when tested at 180°F for heat resistance.

Example 3 Example 3 compares peel strength and substrate fiber tear of laminating adhesives of this invention made with RES 1026 styrene acrylic having a Tg

of -32°C, ethylene vinyl acetate having Tg -5 ±3°C (AP 465) and Tg 10°C ±

10°C (LAM 2) at different levels of water based urethane. The vinyl to particle board laminates were made at 160°F (71 °C), using 2 atmospheres pressure for 3 minutes. Fiber tear was tested at room temperature.

TABLE 3

1 2 3 4 5 6* 7 8 9 10 11

Styrene acrylic 60 60 60 60 60 60 60 60 60 60 60 RES 1026 Tg -32°C

Ethylene vinyl acetate 40 40 40 40 40 40 LAM 2 Tg 10°± 10°C

AP 465 Tg -5 ±3°C 40 40 40 40 40 I

Urethane % 16.7 21 25 28.6 0 0 16.7 21 25 28.6 0 |

Peel Strength 6.8 8.4 8.6 10.2 3.1 5.9 3.6 4.8 7.4 5.0 2.1 I

% Fiber Tear 10 10 10 5 0 10 50 50 65 50 0

'

^*6 also contains glyoxal, itaconic acid and catalyst

Table 3 shows that optimum levels of water based urethane are 25 to 30 percent and that ethylene vinyl acetate polymers having Tg of -5 ±3°C and 10°C ± 10°C are effective in the laminating adhesive of this invention.

Example 4 Tables 4, 5, 6, 7, 8 and 9 report peel strength and fiber tear of

laminating adhesives used with vinyl and wood. Styrene acrylic emulsions having various glass transition temperatures are combined with ethylene vinyl acetate and different levels of aliphatic water based urethane.

TABLE 4

12 13 14 15 16 17 18 19 20 21

Styrene-acrylic UCAR 462¹ 60 60 60 60 60 60 60 60 60 60

LAM2² 40 40 40 40 40

AP 465³ 40 40 40 40 40

% urethane⁴ 16.7 21 25 28.6 0 16.7 21 25 28.6 0 peel strength 2.2 4 5.91 4.3 1.65 1.9 2.9 3.5 2.2 1.8

% fiber tear 90 97 100 100 80 90 100 95 95 80

co

I

¹ Tg 45 ±5

² ethylene-vinyl acetate copolymer emulsion Tg 10°C ± 10°C

³ ethylene-vinyl acetate copolymer emulsion Tg -5°C ±3°

⁴ aliphatic water based urethane

TABLE 5

22 23 24 25 26 27 28 29 30 31 32

Styrene-acrylic 60 60 60 60 60 60 60 60 60 60 60 RES1019⁵

LAM2⁶ 40 40 40 40 40 40

AP465⁷ 40 40 40 40 40

% urethane⁸ 16.7 21 25 28.6 0 0 16.7 21 25 28.6 0 peel strength 3.7 6.1 5.8 3.1 3.1 5.2 2.1 2.6 4.7 5.1 1.8

% fiber tear 2 5 2 2 0 2 90 95 100 99 85

^•Υg -lδ

⁶ ethylene-vinyl acetate copolymer emulsion Tg 10° ± 10°C

⁷ ethylene-vinyl acetate copolymer emulsion Tg -5°± 6°C

⁸ aliphatic water based urethane

TABLE 6

33 34 35 36 37 38 39 40 41 42

Styrene-acrylic HSB6⁹ 60 60 60 60 60 60 60 60 60 60

LAM2¹⁰ 40 40 40 40 40

AP465¹¹ 40 40 40 40 40

% urethane¹² 16.7 21 25 28.6 0 16.7 21 25 28.6 0 peel strength 2.8 3.4 4.3 3.3 1.7 2.8 3.4 6 3.8 2.6

% fiber tear 85 90 100 90 50 90 95 98 100 95

n

I

9 Tg 12 ± 6°C and 48 ± 6°C

¹⁰ethylene-vinyl acetate copolymer emulsion Tg 10°C ± 10°C

¹¹ ethylene-vinyl acetate copolymer emulsion Tg -5°C ± 3°C

¹² aliphatic urethane

TABLE 7

43 44 45 46 47

Styrene-acrylic 60 60 60 60 60 UCAR451¹³

LAM2¹⁴ 40 40 40 40 40

% urethane¹⁵ 16.7 21 25 28.6 0 peel strength 2.9 2.2 2.4 3.3 3

% fiber tear 90 80 85 90 10

CTl I

¹³ Tg 42°C ±5°

¹⁴ ethylene-vinyl acetate copolymer emulsion Tg 10°C ± 10°

¹⁵ aliphatic water based urethane

TABLE 8

48 49 50 51 52

Styrene-acrylic P376¹⁶ 60 60 60 60 60

LAM2¹⁷ 40 40 40 40 40

% urethane¹⁸ 16.7 21 25 28.6 0 peel strength 1.9 3.3 3.3 3.1 3.8

% fiber tear 60 90 90 90 80

¹⁶ Tg -32°C

¹⁷ ethylene-vinyl acetate copolymer emulsion Tg 10° ± 10°C

18 aliphatic water based urethane

TABLE 9

53 54 55 56 57

Styrene-acrylic RES 1018¹⁹ 60 60 60 60 60

LAM2²⁰ 40 40 40 40 40

% urethane²¹ 16.7 21 25 0 0 peel strength 1.9 2.1 3.2 2.2 2.1

% fiber tear 50 65 30 35 60

co

I

¹⁹ +22°Tg

²⁰ ethylene-vinyl acetate copolymer emulsion Tg 10° ± 10° C

²¹ aliphatic water based urethane

Review of Tables 4 through 9 shows that optimum levels of water based

urethane are 35 to 30 percent and that styrene acrylic emulsion having Tg from -32°C to +50°C are effective in the laminating adhesive of this invention.

The most preferred laminating adhesive for strong bonds between vinyl and wood when tested at room temperature is a mixture of a styrene acrylic latex emulsion having a Tg of 45 ± 6°C, an ethylene-vinyl acetate copolymer having a Tg of 10 ± 10°C and a stable non-reactive aliphatic water based urethane.

The most preferred laminating adhesive for strong bonds between vinyl and wood when tested at higher temperatures such as 180°F (82°C) is a mixture of a styrene acrylic latex emulsion having a bimodal glass transition temperature distribution of 12 ± 6°C and 48 ± 6°C, an ethylene vinyl acetate

copolymer having a Tg of 10 ± 10°C, glyoxal, itaconic acid, and, optionally, zinc acetyl acetonate catalyst.

Claims

AMENDED CLAIMS

[received by the International Bureau on 12 Dune 1995 (12.06.95); original claims 1 and 3 amended; new claims 10-12 added; remaining claims unchanged (4 pages)]

1. A method of making a heat stable laminate of a flexible vinyl substrate and a solid substrate adhered together by the dried resiude of a heat activatable solvent-free adhesive composition consisting essentially of the mixture of: a) a styrene-acrylic polymer emulsion having a glass transition temperature of -32°C to +50°C and b) an ethylene-vinyl acetate polymer emulsion having a glass transition

temperature of -8 to 20°C comprising the steps of:

i) applying said adhesive composition using a roll coater onto a vinyl substrate, ii) drying said coated vinyl substrate, iii) rolling said dried coated vinyl substrate, iv) shipping said rolled dried coated vinyl substrate to the laminator customer, v) unrolling said substrate into juxtaposition above a solid substrate, and vi) applying pressure and heat of greater than 71 °C to heat activate said adhesive, whereby a laminate is formed having resistance to heat of greater than 190°F (88°C), said laminate failing by tearing said substrate when tested.

2. The method of Claim 1 wherein said adhesive composition further comprises one or more of . c) polyurethane dispersion, d) organic acid selected from the group of itaconic acid, acrylic acid or methacrylic acid,

e) gloxyal, or,

f) zinc acetyl acetonate catalyst and said activating step v is at 160°F

(71°C).

3. The method of Claim 2 wherein said adhesive comprises 55 to 65 weight

percent styrene-acrylic emulsion, 35 to 45 weight percent ethylene-vinyl acetate emulsion and 1 to 3 percent itaconic acid.

4. The method of Claim 2 wherein said adhesive comprises,

55 to 65 weight percent styrene-acrylic latex emulsion,

35 to 45 weight percent ethylene-vinyl acetate copolymer, and

1 to 3 weight percent glyoxal.

5. The method of Claim 2 wherein said adhesive comprises:

55 to 65 weight percent styrene-acrylic latex emulsion,

35 to 45 weight percent ethylene-vinyl acetate copolymer, and

0.1 to 0.3 weight percent zinc acetyl acetonate catalyst.

6. The method of Claim 2 wherein said adhesive comprises

27 to 34 weight percent styrene-acrylic latex emulsion, 40 to 50 weight percent ethylene-vinyl acetate copolymer, and 16 to 30 weight percent stable non-reactive water-based aliphatic

polyurethane dispersion.

7. The method of Claim 2 wherein said composition comprises a styrene acrylic having a bimodal glass transition temperature of 12 ± 6 °C and 48 ± 6°C, an ethylene-vinyl acetate copolymer having a glass transition temperature of -5

to ± 3°, glyoxal, and itaconic acid whereby said laminate has superior strength when tested at 180°F (82°C).

8. The method of Claim 2 wherein said composition comprises a styrene acrylic having a glass transition temperature of 45 ± 6°C, an ethylene-vinyl acetate copolymer having a glass transition temperature of -5 ± 3°C, and a stable non-reactive aliphatic water based urethane, whereby said laminate has superior strength and good heat resistance when tested at room temperature.

9. The method of Claim 1 wherein said vinyl substrate is polyvinyl chloride substrate and solid substrate is wood.

10. A method of making a heat stable laminate of a flexible vinyl substrate and a solid substrate adhered together by the dried residue of a heat activatable solvent-free adhesive composition consisting essentially of the mixture of: a) a styrene-acrylic polymer emulsion having a glass transition temperature of -32°C to +50°C and b) a vinyl acetate-acrylic copolymer having a glass transition temperature

of O°C to 20°C, and c) a polyurethane dispersion

comprising the steps of: i) applying said adhesive composition using a roll coater onto a

vinyl substrate,

ii) drying said coated vinyl substrate, iii) rolling said dried coated vinyl substrate, iv) shipping said rolled dried coated vinyl substrate to the laminator customer, v) unrolling said substrate into juxtaposition above a solid substrate, and vi) applying pressure and heat of greater than 71 °C to heat activate said adhesive, whereby a laminate is formed having resistance to heat of greater than 190°F (88°C), said laminate failing by tearing said substrate when tested.

11. The method of Claim 10 wherein said styrene-acrylic polymer emulsion is a styrene-butyl acrylate - methyl methacrylate-hydroxyethyl acrylate polymer emulsion.

12. The method of Claim 1 wherein said styrene-acrylic polymer emulsion is a styrene-butyl acrylate-methyl methacrylate-hydroxyethyl acrylate polymer

emulsion. STATEMENT UNDER ARTICLE 19

In response to the 13th April 1995 international search report please amend

the application by removing pages 20, 21 , 22, 23, 24, 25, 26 and 27, replacing them

with the enclosed pages 20a, 21a, 22a, 23a containing claims 1 , 2, 3, 4, 5, 6, 7, 8, 9,

10, 11 , 12.

STATEMENT UNDER ARTICLE 19(1)

Claims 1 , 2, 3, 4, 5, 6, 7, 8, 9 were pending on the application.

Claims 1 , 3 have been amended.

Claims 10, 11 , 12 have been added.

Claims 1 and 3 have been amended and Claims 10, 11 and 12 have been added to more clearly recite the invention.