UV-curable composition and pressure sensitive adhesive having breathability derived therefrom, as well as method for manufacturing the same

Abstract

The present invention relates to a polymerizable composition, comprising a polymerizable monomer of formula (I), a copolymerizable UV-initiator, at least one copolymerizable (meth)acrylic monomer:
R.sup.1(OCH.sub.2CH.sub.2)n-L-OC(O)CR.sup.2?CH.sub.2Formula (I)
wherein R.sup.1 is hydrogen or a C.sub.1-C.sub.6 alkyl group, n is an integer from 1 to 100, L is a single bond or a divalent linking group, preferably a single bond or a C.sub.1-6 alkylene group, and R.sup.2 is hydrogen or a CH.sub.3 group; and optionally (d) at least one copolymerizable non-acrylate monomer;
wherein the amount of the polymerizable monomer of formula (I) is between 2.5 and 40% by weight of the total of all polymerizable monomers (a), (b), (c) and (d). The invention also relates to a random copolymer obtained by reacting the polymerizable composition, a crosslinked product of the random copolymer and an adhesive composite material comprising the random copolymer or the crosslinked product on a substrate.

Claims

1. A polymerizable composition, comprising (a) a polymerizable monomer of formula (I), (b) a copolymerizable UV-initiator comprising an ethylenically unsaturated group, (c) at least one copolymerizable (meth)acrylic monomer,
R.sup.1(OCH.sub.2CH.sub.2)n-L-OC(O)CR.sup.2?CH.sub.2Formula (I): wherein R.sup.1 is hydrogen or a C.sub.1-C.sub.6 alkyl group, n is an integer from 2 to 100, L is a single bond or a divalent linking group, preferably a single bond or a C.sub.1-6 alkylene group, and R.sup.2 is hydrogen or a CH.sub.3 group; and optionally (d) at least one copolymerizable non-acrylate monomer; wherein the amount of the polymerizable monomer of formula (I) is between 2.5 and 40% by weight of the total of all polymerizable monomers (a), (b), (c) and (d); and wherein the copolymerizable UV-initiator is selected from the group consisting of benzophenon(meth)acrylate, benzoin(meth)acrylate and compounds represented by formula (VI) below: ##STR00009## wherein R.sup.2 represents a hydrogen atom or a methyl group, preferably a methyl group, R.sup.al and R.sup.a2, which may be the same or different, each represents a carbonyl group C(O) or an ether linkage O; m represents an integer from 1 to 5, preferably an integer of 1 or 2, further preferably 1; R.sup.3, R.sup.4, and R.sup.5, which may be the same or different, each represent one or two optional substituents, which are preferably selected from C.sub.1-6 alkyl groups, halogens (iodo, chloro, bromo or fluoro), amino groups, nitro groups, nitrile groups, and hydroxyl groups, and if m is an integer of 2 or greater, the m R.sup.a1, R.sup.a2, R.sup.3 and R.sup.4 may respectively be the same or different.

2. The polymerizable composition according to claim 1, which further comprises (e) a solvent selected from alcohols, ethers, ketones, aliphatic and aromatic hydrocarbons, esters and mixtures thereof.

3. The polymerizable composition according to claim 1, wherein the copolymerizable UV- initiator is a compound having an acrylate or methacrylate moiety and a moiety that is decomposed by UV radiation to form radicals.

4. The polymerizable composition according to claim 1 wherein the at least one copolymerizable (meth)acrylic monomer (c) comprises (meth)acrylic acid, butyl (meth)acrylate and/or 2-ethylhexyl methacrylate.

5. A random copolymer obtainable by polymerizing a composition according to claim 1.

6. A hotmelt adhesive composition or a solvent-based adhesive composition comprising the random copolymer according to claim 5 and a solvent.

7. A crosslinked product obtainable by irradiating the random copolymer according to claim 5.

8. The crosslinked product according to claim 7, which has a moisture vapor transmission rate (breathability), MVTR, of at least 250 g/m.sup.2 ?24 h according to UNI4818-26 at a coating weight of 30g/m.sup.2.

9. A composite material comprising the crosslinked product according to claim 7 on a substrate.

10. The composite material according to claim 9, which is in the form of an adhesive sheet or tape, wound dressing, or plaster.

11. A method for forming an adhesive composite material, comprising the steps i. applying the random copolymer according to claim 5 preferably at a temperature of 120 - 160 ? C., onto a substrate; and ii. then irradiating the random copolymer or the hot melt or solvent-based composition with UV irradiation so as to crosslink the copolymer.

12. A method comprising applying the polymerizable composition according to claim 1 to a substrate to form an adhesive tape or sheet, wound dressing or first aid dressing.

Description

EXAMPLES

Example A

(1) Several vinyl-acrylic copolymers that are breathable and UV crosslinkable were prepared as described below:

(2) Sample A was prepared as follows:

(3) A monomer mixture containing as (meth)acrylic monomer (component (c)): 300 g of 2-ethylhexyl acrylate, 86 g of Butyl Acrylate, and 12.5 g of Acrylic Acid, as component (b): 1.5 g of a copolymerizable UV-initiator Visiomer 6976 (from Evonik), a 30% Solution of Benzophenone Methacrylate in Methyl Methacrylate/Methacrylic Acid, as component (a): 50 g of Bisomer MPEG 550 MA (a monomer providing breathability according to formula (I), a methoxy polyethyleneglycol methacrylate, average molecular weight 550 g/mol) and as component (d) 70 g of vinyl acetate;
was prepared in a glass vessel and stirred.

(4) Thus, in this monomer mixture there is a total of 70 g of component (d), 399.55 g component (c), 0.45 g of component (b) and 50 g of component (a). In view of the total mass of 520 g of these monomers, this corresponds to 13.46% by weight of component (d), 76.83% by weight of component (c), 0.09% of component (b) and 9.62% of component (a).

(5) A catalyst solution (also referred to as initiator solution in the following) was prepared by mixing 1 g of TBPEH (Tert-Butyl peroxy-2-ethylhexanoate) and 120 g of a mixture 55:45 of Heptane/Ethyl Acetate was prepared in a different vessel.

(6) In a lab reactor (a 3 liter water jacketed reactor), an initial charge was prepared as follows: 200 g of a mixture 55:45 of Heptane/Ethyl Acetate, 130 g of the Monomer Mixture and 30.25 g of the catalyst solution were charged. This initial charge was stirred at 100 rpm and purged with nitrogen, then heated to reflux at 77-80? C. (the heating jacket was set to 92? C.). Around 7 minutes after reaching reflux, the heating jacket was set at 90? C. and the remainder of the monomer mixture and the catalyst solution were uniformly added into the reactor over 2.5 hours (the internal temperature of the reactor was around 80-85? C.)

(7) At the end of the addition, the monomer tank was washed with 20 g of a mixture 55:45 of Heptane/Ethyl Acetate and added into the reactor, then the reactor was held at reflux for 1 hour.

(8) 3.5 hours after the start of the feeding, the residual monomers were scavenged with a initiator solution of 1 g of TBPEH and 60 g of a mixture 55:45 of Heptane/Ethyl Acetate. The jacket was set down to 88? C. and the scavenger solution was added for 1 h at constant rate. At the end of the addition, the tank was finally washed with 20 g of a mixture 55:45 of Heptane/Ethyl Acetate, and the reactor was held at reflux for other 3.0 hours (with the internal temperature between 77 and 80? C.), maintaining the jacket at 88? C.

(9) Finally, 7.5 hours after the start of the feeding of the monomer mixture the reactor content was cooled and diluted with 58 g of a mixture 55:45 of Heptane/Ethyl Acetate.

(10) The final product obtained has a solid content of 51.9% and a Viscosity of 3620 mPa*s.

(11) The product can be used as solvent-based adhesive composition or can be dried (by removing the solvent) to obtain a hotmelt adhesive composition. The results are summarized in Table 2.

(12) The results in table 2 relate to the material after solvent evaporation and application on a substrate (PET 36 microns film) with a coating weight of 30 g/m.sup.2, and then crosslinking with a UV lamp emitting UV-C irradiation at an intensity of 30 mJ/cm.sup.2.

Examples B-E

(13) Further Examples were prepared as outlined above for Example A, mainly varying the amount of the breathable monomer (a) of formula (I) as recited in Table 1. The amount of the other monomers (c) and (d) were reduced to maintain the same total monomer quantity. In the Examples with high quantity of breathable monomer (a), also the initial solvent quantity was increased in order to maintain a similar viscosity.

(14) In the tables, the following abbreviations are used: 2-EHA=2-Ethyl Hexyl Acrylate AB=Butyl Acrylate AM=Methyl Acrylate AVM=Vinyl Acetate Monomer AA=Acrylic Acid UV Mon1=Visiomer? 6976 (a 30% Solution of Benzophenone Methacrylate in Methyl Methacrylate/Methacrylic Acid) UV Mon2=Esacure? BHM (4-benzoyl-4-(2-methyl-propenoyl)-diphenyl ether) Breath Mon 1=Bisomer? MPEG 550 MA (a methoxy polyethyleneglycol methacrylate, average molecular weight 550 g/mol) Breath Mon 2=Bisomer? MPEG 350 MA (a methoxy polyethyleneglycol methacrylate, average molecular weight 350 g/mol) Breath Mon 3=Bisomer? S 20 W (a 50% water solution of Bisomer MPEG 2000MA; a methoxy polyethyleneglycol methacrylate, average molecular weight 2080 g/mol Breath Mon 4=Rhodasurf? AAE/10-E, an allyl alcohol ethoxylate with ethoxy chains of around 10 moles from Rhodia TBPEH=Tert-Butyl peroxy-2-ethylhexanoate from Degussa Vazo 64?=2,2-azobis-(2-isobutyronitrile) from DuPont Laurox?=dilauryl peroxide (Akzo Chemical) Solv Mix1=Solvent Mixture: 55% Heptane+45% Ethyl Acetate Solv Mix2=Solvent Mixture: 55% Ethanol+45% Ethyl Acetate Exxsol? DSP 60/95 SH=a dearomatized hydrocarbon fluid, mainly a mixture of Hexane(s) and Heptane(s) isomers with a low level of n-Hexane

(15) In the following tables, values in brackets ( ) indicate that the respective amount of the respective component relates to a composition defined previously, and are hence disregarded for the calculation of the total amount. For instance, the value of (130) for the Monomer mixture in the section Initial Charge denotes the amount of 130 g of the Monomer mixture defined at the top of the table (consisting e.g. for Ex. A of 300 g 2-EHA, 86 g AB, 70 g AVM, 12.5 g AA, 1.5 g UV Mon1, and 50 g Breath Mon1).

(16) TABLE-US-00001 TABLE 1 Examples A to E Components (g) Ex. A Ex. B Ex. C Ex. D Ex. E Monomer Mixture 2-EHA 300.0 320.0 315.0 275.0 250.0 AB 86.0 86.0 86.0 86.0 76.0 AVM 70.0 100.0 80.0 45.0 30.0 AA 12.5 12.5 12.5 12.5 12.5 UV Mon - 1 1.5 1.5 1.5 1.5 1.5 Breath 50.0 25.0 100.0 150.0 Mon - 1 Initiator solution TBPEH 1.0 1.0 1.0 1.0 1.0 Solv Mix - 1 120.0 120.0 120.0 120.0 120.0 Initial Charge Solv Mix - 1 200.0 200.0 200.0 250.0 290.5 Mon Mixture (130) (130) (130) (130) (130) Initiator (30.25) (30.25) (30.25) (30.25) (30.25) solution Washing Mon Tank Solv Mix - 1 20.0 20.0 20.0 20.0 20.0 Scavengers TBPEH 1.0 1.0 1.0 1.0 1.0 Solv Mix - 1 60.0 60.0 60.0 60.0 60.0 Wash Ini Tank Solv Mix 2 20.0 20.0 20.0 20.0 20.0 Dilution Solv Mix - 1 58.0 78.0 58.0 8.0 37.5 Total 1000 1020 1000 1000 1070

(17) The final products (without removal of the solvents) were analyzed to determine: (a) the analytical properties: solid content, viscosity of the liquid product, and Molecular Weight (measures by GPC (Gel Permeation Chromatography) in THF using a Polystyrene internal standard (b) the adhesive performances of an adhesive film (with a coating weight of 30 g/m.sup.2), obtained by evaporating the solvent, coating the copolymer on a PET 36 microns film and then crosslinking with a UV lamp with UV-C of 30 mJ/cm.sup.2. (c) the MVTR, following UNI 4818-26

(18) Table 2 summarizes the results. Herein:

(19) A means adhesive failure on a stainless steel surface.

(20) D means disanchorage failure of the adhesive on Polyester surface.

(21) C means cohesive failure (the adhesive remains on both surfaces (polyester and stainless steel)).

(22) The viscosity was measured using a Brookfield Mod RVT at 25? C. at 20 rpm. The solids content was determined by putting the product for 1 hour at 130? C. into a ventilated oven. The Peel Adhesion)(180? on stainless steel (ss) was measured according to FINAT Test Method (FTM1) at a dwell time of 20 minutes. The shear value was measured according to FTM8 at room temperature, using a weight of 1 kg at controlled surface areas of 1 square inch ((1).sup.2) and ? square inch ((?).sup.2. The loop tack (=QS ss) was measured according to FTM9 on stainless steel. MVTR was measured according to UNI 4818-26.

(23) TABLE-US-00002 TABLE 2 Examples A to E: Analysis UM Ex. A Ex. B Ex. C Ex. D Ex. E Analytical data Solid Content wt.-% 51.9 50.4 51.3 52.0 48.6 Viscosity Mpa .Math. s 3620 3010 2600 4220 1920 Mn 41350 84000 68700 29000 22000 Mw 190000 312000 273000 55000 50100 Adhesive Performance Peel ss 20 min G/25 mm 800 1320 1130 300 200 QS ss G/25 mm 810 1040 1150 500 370 Shear ((?).sup.2 min 160D 660C/D 300C/D 70A 20A Shear (1)2 h >100 >100 >100 >100 >100 Breathability MVTR g/m.sup.2 24 h 375 250 265 500 650

(24) It is clear to see the influence of the quantity of the breathable monomer (a), i.e. the monomer of formula (I), on the MVTR. Increasing the quantity (% of total monomer quantity) leads to a significant increase of the MVTR of the adhesive film, as summarized in Table 2a below:

(25) TABLE-US-00003 TABLE 2a Examples A to E: MVTR vs % of Monomer (a) Example B C A D E Monomer (a) Wt.-% of 4.8 9.6 19.2 28.8 all monmers MVTR a/m.sup.2 24 h 250 265 375 500 650

(26) The quantity of the monomer (a) also has influence on the adhesive performances of the film: increasing the amount thereof leads to a reduction of the Peel strength of the film, a slight reduction of the Quick Stick (Loop Tack), while the influence on the shear value is less evident due to the high level of the UV monomer and the high crosslinking in the film.

Examples F-M

(27) A second series of examples were prepared using a pure acrylic polymer (i.e. monomer (d) is absent). Table 3 summarizes the compositions.

(28) The procedure is similar to the first series of Examples A-E, the differences being as follows: the waiting time after the start of the reaction was increased to 30 min; the feeding time was reduced to 90 min; the scavenger addition time reduced to 45 min; total reaction time (from start of the monomer addition, including delay and cooling) was reduced to 6 h 15 min.

(29) Further, a different solvent mixture was used (Solv Mix2) consisting of 55% by weight of ethanol and 45% by weight of ethyl acetate.

(30) Examples F-M relate to a pure acrylic polymer. Also, the UV copolymerizable photoinitiator was different, and a comparison of two different breathable monomers (a) is made to evaluate the influence of the quantity and nature (in particular ethoxy chain length) of the breathable monomer (a) on the properties of the product and the dried adhesive film.

(31) The following components were used: Breath Mon 1=Bisomer MPEG 550 MA (ethoxy chain around 10 EO moles) Breath Mon 2=Bisomer MPEG 350 MA (ethoxy chain around 6 EO moles)

(32) To maintain the same total monomer quantity, the quantity of the acrylic momomers 2-EHA and AM were reduced, as shown in Table 3.

(33) TABLE-US-00004 TABLE 3 Examples F to M Components (g) Ex. F Ex. G Ex. H Ex. I Ex. L Ex. M Mon Mixture 2-EHA 323.0 323.7 283.0 283.0 248.0 248.0 AM 150.0 150.0 140.0 140.0 125.0 125.0 AA 25.0 25.0 25.0 25.0 25.0 25.0 UV Mon - 2 2.0 1.3 2.0 2.0 2.0 2.0 Breath Mon - 2 50.0 100.0 Breath Mon - 1 50.0 100.0 Initiator Sol. TBPEH 0.8 0.8 0.8 0.8 0.8 0.8 Solv Mix - 2 140.0 140.0 140.0 140.0 140.0 140.0 Initial Charge Solv Mix - 2 80.0 80.0 80.0 80.0 80.0 80.0 Mon Mixture (250.0) (250.0) (250.0) (250.0 (250.0) (250.0) Initiator Sol. (70.4) (70.4) (70.4) (70.4) (70.4) (70.4) Wash Mon Tank Solv-Mix 2 50.0 50.0 50.0 50.0 50.0 50.0 Scavengers TBPEH 0.7 0.7 0.7 0.7 0.7 0.7 Solv Mix - 2 40.0 40.0 40.0 40.0 40.0 40.0 Wash Ini Tank Solv Mix 2 20.0 20.0 20.0 20.0 20.0 20.0 Dilution Solv Mix 2 148.5 148.5 148.5 148.5 148.5 148.5 Total 980 980 980 980 980 980

(34) In table 4 are collected the analysis of the lab trials.

(35) TABLE-US-00005 TABLE 4 Examples F to M: Analysis Ex. F Ex. G Ex. H Ex. I Ex. L Ex. M Analytical data Solid Content % 52.2 52.0 51.6 51.1 50.7 51.0 Viscosity MPa s 1450 1440 1570 1590 2350 1975 Adhesive Performance Peel ss 20 min G/25 mm 1500 1850 1075 1120 825 650 QS ss G/25 mm 1450 1570 1220 1095 825 720 Shear (?).sup.2 min 2200A 100C 960A 900A 130A 80A Shear (1).sup.2 h >100 8.5C >100 >100 >100 >100 Breathability MVTR G/sm 24 h 180 190 270 290 370 440

(36) From this table it is derived that: as for the first series of experiments, increasing the quantity of monomer (a) increases the MVTR and reduces the adhesive performances of the film; Breath Mon1, having a slightly longer EO chain than Breath Mon2, has a bigger influence on the MVTR of the film, especially for high level of the monomer, see Table 4A.

(37) TABLE-US-00006 TABLE 4A Examples F to M: MVTR on Breath Mon 1 and 2% Example F H L Breath Mon - 2 % of Monom 10.0 20.0 MVTR g/m.sup.2 24 h 180 270 370 Example F I M Breath Mon - 1 % on Monom 10.0 20.0 MVTR g/m.sup.2 24 h 180 290 440

Examples N-P

(38) A third series of examples was made by introducing a new breathable monomer, Bisomer S 20 W from GEO Chemical. It is a copolymerizable monomer with a very long EO chain (around 43 moles), supplied as a 50% solution in water. The values in Table 5 relate to the amount of solution. The reaction procedure is the same as used in Examples A to E, except for the following: The solvent used was Ethyl Acetate, and the initiator used was Vazo 64.

(39) TABLE-US-00007 TABLE 5 Examples N to P Components (g) Ex. N Ex. O Ex. P Mon Mixture 2-EHA 391.2 378.7 365.9 AB 92.7 80.2 68.0 AA 13.6 13.6 13.6 UV Mon - 1 2.5 2.5 2.5 Breath Mon - 3 25.0 50.0 Initiator Sol. Vazo 64 1.0 1.5 2.0 Ethyl Acetate 99.0 98.5 98.0 Initial Charge Ethyl Acetate 100.0 150.0 220 Mon Mixture (125.0) (125.0) (125.0) Initiator Sol. (25.0) (25.0) (25.0) Washing Mon Tank Ethyl Acetate 70.0 30.0 40.0 Scavengers Vazo 64 0.8 0.8 0.8 Ethyl Acetate 49.2 49.2 49.2 Washing Init. Tank Ethyl Acetate 20.0 20.0 20.0 Dilution Ethyl Acetate 160.0 150.0 70.0 Total 1000 1000 1000

(40) Table 6 summarizes the properties of the materials obtained. It is derived that long EO chains have a big influence on the MVTR properties of the film: a quantity of around 5% of the breathable monomer (a) is enough to give an MVTR of 360 g/m.sup.2?24 h; the long EO chain and the water content influence the viscosity of the product.

(41) TABLE-US-00008 TABLE 6 Examples F to M: Analysis Ex. N Ex. O Ex. P Analytical data Solid Content % 50.0 49.1 47.4 Viscosity MPa s 2000 2200 4000 Adhesive Performance Peel ss 20 min G/25 mm 580 420 370 QS ss G/25 mm 670 680 750 Shear (?).sup.2 min 200 A 180 A 300 A Shear (1).sup.2 h >100 >100 >100 Breathability MVTR g/m.sup.2 24 h 215 260 360

(42) Table 6a demonstrates the influence of the monomer (a) on the breathability properties of the resulting film:

(43) TABLE-US-00009 TABLE 6A Examples N to P: MVTR vs amount of Breathable Monomer 3% Example N O P Breath Mon - 3 % of Monom 2.6 5.2 MVTR g/m.sup.2 ? 24 h 215 260 360

Examples Q-T

(44) A fourth series of examples was prepared using a pure acrylate polymer (i.e. monomer (d) is absent) to investigate, in a simple monomer composition system (Butyl Acrylate and Acrylic Acid), the influence of a an amount of a monomer (a) like Bisomer MPEG 350 MA for very high level (up to 40%) of the total monomer composition.

(45) The procedure is similar to the first series of examples A-F, the differences are in the timing: feeding time reduced to 135 min; scavenger addition reduced to 45 min; post-reaction time after scavenger addition was reduced to 150 min; total reaction time (from start of monomer delay until cooling) reduced to 6 h 30 min.

(46) Table 7 summarizes the compositions of the Examples, the only differences being in the monomer quantity of component (a), which is compensated for by the amount of butyl acrylate. The solvent was Ethyl acetate and the initiator was Vazo 64.

(47) TABLE-US-00010 TABLE 7 Examples Q to T Components (g) Ex. Q Ex. R Ex. S Ex. T Mon Mixture AB 473.5 373.5 323.5 273.5 AA 25.0 25.0 25.0 25.0 UV Mon - 1 1.5 1.5 1.5 1.5 Breath Mon - 2 100.0 150.0 200.0 Ethyl Acetate 50.0 50.0 50.0 50.0 Initiator Sol. Vazo 64 2.0 2.0 2.0 2.0 Ethyl Acetate 48.0 48.0 48.0 48.0 Initial Charge Ethyl Acetate 200.0 200.0 200.0 200.0 Mon Mixture (165.0) (165.0) (165.0) (165.0) Initiator Sol. (15.0) (15.0) (15.0) (15.0) Washing Mon Tank Ethyl Acetate 20.0 20.0 20.0 20.0 Scavengers Vazo 64 0.7 0.7 0.7 0.7 Ethyl Acetate 49.3 49.3 49.3 49.3 Washing Ini Tank Ethyl Acetate 20.0 20.0 20.0 20.0 Dilution Ethyl Acetate 110.0 110.0 110.0 110.0 Total 1000.0 1000.0 1000.0 1000.0

(48) Table 8 summarizes the analytical results of these examples.

(49) TABLE-US-00011 TABLE 8 Examples Q to T: Analysis UM Ex. Q Ex. R Ex. S Ex. T Analytical data Solid Content wt.-% 51.4 51.0 51.2 51.3 Viscosity MPa s 2350 4050 6070 6300 Adhesive Performance Peel ss 20 min G/25 mm 2820 Tr 990 Tr 780 340 QS ss G/25 mm 1740 1070 930 580 Shear (?).sup.2 min 170 A 210 A 110 A 45 A/D Shear (1).sup.2 h >100 >100 >100 >100 Breathability MVTR g/m2 24 h 255 420 550 650

(50) Also in this case is clear to see the influence of the quantity of the breathable monomer (a), i.e. Breath Mon2, on the MVTR.

(51) Increasing the Breath Mon2 quantity leads to a significant increase of the MVTR of the adhesive film. A very high quantity of the breathable monomer (a) leads to a very high breathability of the polymer; this behavior is summarized in table 8A:

(52) TABLE-US-00012 TABLE 8A Examples Q to T: MVTR vs amount of Breath Mon 2 Example Q R S T Breath % of 20.0 30.0 40.0 Mon - 2 Monomers MVTR g/m.sup.2 ? 24 h 255 420 550 650

(53) As demonstrated in the previous examples, the quantity of the monomer (a) also influences the adhesive performance of the film: an increase leads to a reduction of the Peel strength of the film and a slightly smaller reduction of the Quick Stick (Loop Tack).

(54) The amount of monomer (a) also influences the viscosity of the product: without changing the amount of the other components, an increase in the amount of monomer (a) leads to an increase of the viscosity of the liquid product.

Examples U-Z

(55) A fifth series of examples were prepared using a pure acrylate polymer (i.e. monomer (d) is absent); to check, in a simple monomer composition system (2-Ethyl-Hexyl Acrylate and Acrylic Acid) the influence of a different monomer (a) like Rhodasurf AAE/10-E (from Rhodia).

(56) Different is also the used solvent: Exxsol DSP 60/95 SH=a dearomatized hydrocarbon fluid, which is a mixture of Hexanes and Heptane isomers with a low level of n-Hexane

(57) The procedure is similar to the first series of examples, the differences are in the timing: feeding time was reduced to 120 min; scavenger addition was reduced to 45 min; post-reaction time after scavenger addition was reduced to 150 min; total reaction time (from monomer delay start to cooling) was reduced to 6 h 15 min.

(58) The initiator were: TBPEH and Laurox (dilauryl peroxide from Akzo).

(59) Table 9 summarizes the compositions of Examples U to Z.

(60) TABLE-US-00013 TABLE 9 Examples U to Z Components Ex. U Ex. V Ex. Z Mon Mixture 2-EHA 473.0 423.0 373.0 AA 25.0 25.0 25.0 UV Mon - 1 2.0 2.0 2.0 Breath Mon - 4 50.0 100.0 Exxsol DSP 60/95 SH 50.0 50.0 50.0 Initiator Sol. TBPEH 2.7 1.5 0.7 Exxsol DSP 60/95 SH 47.3 48.5 49.3 Initial Charge Exxsol DSP 60/95 SH 270.0 150.0 70.0 Mon mixture (220.0) (220.0) (220.0) Initiator Sol. (20.0) (20.0) (20.0) Washing Mon Tank Exxsol DSP 60/95 SH 40.0 40.0 40.0 Scavengers Laurox 0.5 0.5 0.5 Exxsol DSP 60/95 SH 49.5 49.5 49.5 Washing Ini Tank Exxsol DSP 60/95 SH 20.0 20.0 20.0 Dilution Exxsol DSP 60/95 SH 120.0 200.0 Total 980.0 980.0 980.0

(61) Table 10 summarizes the analytical results of these Examples.

(62) TABLE-US-00014 TABLE 10 Examples U to Z: Analysis UM Ex. U Ex. V Ex. Z Analytical data Solid Content wt.-% 52.5 52.6 51.6 Viscosity MPa s 22700 2020 850 Adhesive Performance Peel ss 20 min G/25 mm 2250 Tr 970 Tr 130 Tr QS ss G/25 mm 1310 1100 Tr 500 Tr Shear (1).sup.2 min 5 1 0.05 Transpirancy MVTR g/m2 24 h 200 350 450

(63) Also in this case, it is clear to see the influence of the quantity of the breathable monomer (a), i.e. Breath Mon4, on the MVTR.

(64) Increasing the Breath Mon4 quantity (% on tot monomer quantity) leads to a significant increase of the MVTR of the adhesive film. This is summarized in table 10 A:

(65) TABLE-US-00015 TABLE 10A Examples U to Z: MVTR on Breath Mon 4% (on monomers) Example U V Z Breath Mon - 4 % on Monom 10.0 20.0 MVTR a/m2 24 h 200 350 450

(66) As seen in the previous examples, the quantity of the monomer (a) also influences the adhesive performance of the film: increasing the Breath Mon4 quantity correlates with a reduction of the adhesive properties of the film.

(67) It is also clear that the amount of the breathable monomer (a) influences the viscosity of the product, since increasing the Breath Mon 4 quantity leads to a strong reduction of the molecular weight of the polymer.