Curable Composition and Cured Product Having Anti-Microbial Properties

Abstract

The present invention relates to curable compositions which can preferably be used for making products with an intrinsically antimicrobial effect. In addition, the present invention relates to the use of this curable composition in various processing methods.

Claims

1. A Curable composition, containing (a) a compound with a radically reactive double bond selected from an unsaturated polyester, a vinyl ester and vinyl ester urethane, and mixtures thereof and (b) a methacrylate or acrylate selected from tert.-butylaminoethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, tert.-butylaminoethyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate and mixtures thereof.

2. The curable composition as claimed in claim 1, wherein the unsaturated polyester is obtainable by reacting a dicarboxylic acid or a derivative of the dicarboxylic acid and a diol, the dicarboxylic acid being a compound of formula (I) ##STR00003## where R.sup.1 is selected independently from H, CH.sub.3 and CH.sub.2COOH, and R.sup.2 and R.sup.3 are selected independently from H, CH.sub.3 and COOH.

3. The curable composition as claimed in claim 2, wherein the dicarboxylic acid is fumaric acid, mesaconic acid, maleic acid, citraconic acid or itaconic acid or anhydrides thereof.

4. The curable composition as claimed in either of claim 2 or 3, wherein the dicarboxylic acid is itaconic acid or its anhydride.

5. The curable composition as claimed in any of claims 2 to 4, wherein the diol selected from the group of 1,2-ethylene glycol, 1,2-propanediol, 1,3-propanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, neopentyl glycol, butane-1,3-diol, butane-1,2-diol, butane-2,3-diol, butane-1,4-diol, 2-butyl-2-ethyl propanediol-1,3, 2-methyl propane-1,3diol, 2,2,4-trimethyl pentanediol-1,3, 2-ethyl-2-methyl propane-1,3-diol, 2,2-diethyl propanediol-1,3, 2-propyl-2-methyl propanediol-1,3, pentane-1,5-diol, hexane-1,6-diol, 2,4-dimethyl-2-ethyl hexane-1,3-diol, hydroxypivalic acid neopentyl glycol ester, isosorbide, tricyclodecane dimethanol, perhydrogenated bisphenol A, 2,2,4,4-tetramethyl cyclobutanediol-1,3, 1,4-cyclohexane dimethanol, ethoxylated and propoxylated bisphenol A or mixtures thereof.

6. The curable composition as claimed in claim 1, wherein the vinyl ester is obtainable by reacting methacrylic acid and/or acrylic acid with bisphenol A-based, bisphenol F-based and novolak-based glycidyl ethers.

7. The curable composition as claimed in claim 1, wherein the vinyl ester urethane is obtainable by reacting hydroxyalkyl acrylate and/or hydroxyalkyl methacrylate with diisocyanates and/or triisocyanates and/or polyisocyanates and optionally diol and/or triol and/or tetrol.

8. The curable composition as claimed in any of claims 1 to 7 containing 20 to 100% by weight of the mixture of components (a) and (b) 0 to 80% by weight reactive diluent (c) 0 to 4% by weight initiator 0 to 60% by weight filler 0 to 60% by weight fibres 0 to 10% by weight additives (d), based on the total weight of the curable composition.

9. Use of the composition as claimed in any of claims 1 to 8 in any of the following processing methods: coating, painting, casting, dip coating, laminating, gap impregnation, centrifugation, bonding, resin injection, pressing, injection moulding, pultrusion, filling and levelling, and winding.

10. Method of preparing cured products, wherein a curable composition as claimed in any of claims 1 to 8 is cured.

11. The method as claimed in claim 10, wherein the curable composition as claimed in any of claims 1 to 8 contains a photoinitiator and is cured by irradiation.

12. A product with an antimicrobial effect obtainable by curing a curable composition as claimed in any of claims 1 to 8.

13. The product as claimed in claim 12, wherein the product has a water absorption after seven days of 0.5 to 35%.

14. The product as claimed in either of claim 12 or 13, wherein the glass transition temperature T.sub.G (measured at 10 Hz) is 50 C. to 150 C.

15. Use of the curable composition as claimed in any of claims 1 to 8 to make the following products: furniture and furniture surfaces, adhesives, veneers and paper laminates, buttons, handles, push buttons, switches and housings, plates, flooring, pipes, profiles, tanks and containers of all kinds, especially for drinking water, foodstuffs and oils, linings of all kinds, roof coatings, light panels, sealing compounds, putties, dowel compounds, polymer concrete, agglomerated marble, kitchen sinks, shower trays, bath tubs, wash basins, lavatory seats, garden furniture, garden fences, faade panels, cellar window shafts, vehicle parts, luminaires, wind power plants, impregnations, binders, grouting compounds, filling compounds and/or reaction mortar, coatings, varnishes, gelcoats, topcoats, ships, boats.

Description

EXAMPLES

[0121] The invention will now be illustrated with reference to the following examples. In this context, a general production method will first be described in sections 1 and 2. In section 3, measuring the antimicrobial activity is explained, and in section 4 the results of the products produced are summed up.

1.1 Preparation of the Unsaturated Polyester (a)

[0122] For the purposes of preparation, the same condensation conditions were selected in each case in order to ensure that the products were easily comparable. The precise composition of the polyesters prepared can be seen from the table of results in item 4.

[0123] The respective diols, the itaconic acid, 400 ppm Fascat 4100 (butyl tin acid) as an esterification catalyst and 300 ppm hydroquinone as an inhibitor were poured into a 2 l four-necked flask, which was clamped beneath the stirrer. In order to prevent the educts from distilling off, a packed column was used. Purging with nitrogen continued throughout the entire reaction time in order to prevent gelling and at the same time to support the removal of the water of condensation. There was a thermometer in the flask to monitor the temperature accurately. The raw materials were then melted at 100 C. As soon as the melt was stirrable, the temperature was raised to 140 C. and kept there for one hour, then raised to 150 C. and kept there for 0.75 hours. The temperature was then raised to 160 C. and increased by 10 C. every half hour up to a temperature of 180 C. The temperature was kept at 180 C. for 0.5 hours, then raised to 185 C. and kept there for six hours. The water of condensation formed during the reaction was trapped in order to be able to assess the progress of the reaction.

1.2 Preparation of the Vinyl Ester Urethanes (a)

[0124] 0.25 g (600 ppm) 3,5 di-tert.-butyl-4-hydroxyl toluene (BHT), 0.03 g (60 ppm) 4-methoxyphenol (HQME), 57.68 g (0.4 mol) 2-hydroxypropyl methacrylate (HPMA), 0.2 mol of the chain extender (tert.-butyl-bis-hydroxyethylamine or dipropylene glycol) and 200 ml anhydrous acetone were poured into a three-necked flask. The mixture was heated to 65 C. with constant stirring. Once the reaction temperature had been reached, 101.08 g (0.404 mol) Lupranat MI from BASF SE (49% by weight 4,4-methylene diphenyl diisocyanate, 49% by weight 2,4-methylene diphenyl diisocyanate, 2% by weight 2,2-methylene diphenyl diisocyanate) were added dropwise in such a way that the reaction mixture reached a constant temperature of between 65 C. and 75 C. The heat created was dissipated via a water bath. After everything had been added dropwise (25 minutes), the mixture was stirred for another 1 hour.

1.3 Vinyl Ester (a)

[0125] In the present experiments, (1-methylethylidene)bis[4,1-phenyleneoxy(2-hydroxy-3,1-propanediyl)]bis methacrylate (M=512.59 g/mol) was used as the vinyl ester, obtainable from Sigma Aldrich, product number: 494356.

2. Preparation of the Curable Composition and of the Cured Product

[0126] 2.1 In order to prepare the curable composition (UP resin), the corresponding amount of acrylate and/or methacrylate component (b) was added to the unsaturated polyester (a). After rotating on a rolling stand, a transparent resin was left after approx. 14 days.

[0127] 2.2 In order to prepare the curable composition (VEU resin), the corresponding amount of acrylate and/or methacrylate component (b) was added to the vinyl ester urethane (a), and the acetone only at normal pressure and then stripped in a vacuum until the total mass in the flask remained constant.

[0128] 2.3 In order to prepare the curable composition (VE resin), the corresponding amount of acrylate and/or methacrylate component (b) was added to the vinyl ester (a).

[0129] After that, 1.75% by weight of the UV initiator Irgacure 819 was added to each composition prepared and dissolved. About 8 g of the transparent solution mixed with initiator were placed on various glass Petri dishes and exposed for five minutes in a Suntester from Original Hanau under a nitrogen atmosphere in order to obtain a cured sample. The fully cured product obtained (duromer) was tack-free and hard. The product was virtually odorless and exhibited excellent antimicrobial properties.

3. Examination of the Antimicrobial Property

[0130] The method used in the antimicrobial examinations is based on the Japanese Standard JIS Z 2801:2000. The test microorganism for the experiments was the pathogenic germ Staphylococcus aureus. A standard germ (ATCC 6538) was used, which is not multiresistent.

[0131] With each test germ (in this case Staphylococcus aureus), a microorganism-specific germ count is adjusted under the conditions under which the starting solution or starting suspension was prepared. In the case of Staphylococcus aureus, that figure was 10.sup.8 germs per ml (see also comments below).

[0132] The antimicrobial activity was determined by comparing the growth of Staphylococcus aureus on reference surfaces and on the sample materials.

[0133] Empty Petri dishes were used as the reference material. The samples consisted of Petri dishes into each of which was poured a thin layer of a polymer sample. For each test series, three reference plates were used to determine the initial germ count (separate experiment, independently of the examination into the antimicrobial behaviour) and three reference plates and three sample plates to determine the surface germ count after incubation.

[0134] All the plates were inoculated with 400 l Staphylococcus aureus inoculation suspension, which had been adjusted to a germ count of 4.0-10.Math.10.sup.5 CFU/ml.

[0135] The inoculation suspension applied was covered with a sterile PP film in order to avoid evaporation. Immediately after inoculation, the three sample plates and three reference plates were transferred to an incubation cabinet and stored for 2 h or 24 h at 35 C. and 90% relative humidity.

[0136] In order to determine the germ count in the inoculation solution (initial germ count), three reference plates each were washed out immediately after inoculation, with 10 ml SCDLP broth (soybean casein peptone broth with lecithin and polyoxyethylene medium) added to the Petri dish. The film was turned over with sterile tweezers and rinsed top and bottom several times with a 1 ml pipette. The Petri dish was swirled in the form of a figure of eight before 1 ml of the rinsing solution was pipetted into the first dilution stage. After a dilution series had been prepared, the live germ count was determined by means of the drop plate method. In the drop plate method 5 drops per 10 lusing twin batcheswere placed on a plate-count (PC) agar plate in each sector of the dilution stage concerned. The plates were incubated for 2 h and 24 h respectively at 37 C.

[0137] The steps of rinsing and determining the live germ count on the reference and sample plates after incubation were carried out in the same way in which the initial germ count was determined. In the case of the sample plates, in order to enhance the detection threshold, the germ count in the direct rinsing solution was determined using the pour plate method. For this purpose, again using twin batches, 1 ml of the solution was poured into an empty Petri dish, and liquid PC agar, heated to 45 C., was poured over it. The bacteria were distributed in the agar by swirling the dish in the form of a figure of eight. The plates were incubated for 48 h at 37 C.

[0138] After the incubation, the colonies in the Petri dish were counted. It was assumed that a visible colony had formed from each germ. The colonies were visible with the naked eye after incubation. Alternatively, it was possible to use a light table so that the germs could be recognised better.

[0139] On the basis of the volume of the inoculation solution and the dilution ratios used, it was possible to draw conclusions as to the live germ count of the microorganisms per unit of volume (i.e. per ml) inoculation solution. The calculation was performed on the basis of the weighed arithmetical average with the following formula:

[00004]$\stackrel{\_}{c}=\frac{c}{n_1.Math.1+n_2.Math.0,1}.Math.d$

where
c weighed arithmetical average
c sum of the colonies on all Petri dishes or sectors included in the calculation
n.sub.1 number of Petri dishes or sectors in the lowest analysable dilution stage
n.sub.2 number of Petri dishes or sectors in the next-higher dilution stage
d factor of the lowest analysable dilution stage

[0140] With the pour plate method, Petri dishes with up to 300 CFU (colony-forming units) could be counted. With the drop plate method, only plates with up to 150 CFU per sector were analysable.

[0141] When determining the live germ count per ml, the dilution factor F.sub.1 had to be taken into account. That resulted from the sum of the volume of the SCDLP broth and the volume of the bacteria suspension on the inoculated plate divided by the volume of the bacteria suspension on that inoculated plate.

[00005]$F_1=\frac{10.Math..Math.\mathrm{ml}-0,4.Math..Math.\mathrm{ml}}{0,4.Math..Math.\mathrm{ml}}=26$

[0142] F.sub.1 dilution factor of the SCDLP broth.

[0143] For the total germ count on the inoculated sample and reference plates in the pour plate method, this resulted in the following formula:

[00006]$\mathrm{KbE}=\frac{c}{n_1.Math.1+n_2.Math.0,1}.Math.d.Math.F_1$

KbE CFU

[0144] In the drop plate method, only one further dilution factor was relevant, since a quarter of a plate was only inoculated with 50 l, i.e. 0.05 ml. In order to draw conclusions about the germ count per ml, 0.05 ml had to be recalculated to 1 ml by multiplying by 20.

F.sub.2=26.Math.20

[0145] F.sub.2 dilution factor to obtain the CFU per ml in the drop plate method.

[0146] The total germ count on the inoculated sample and reference plates in the drop plate method was thus calculated, taking all the dilution factors into account, according to the following formula:

[00007]$\mathrm{KbE}=\frac{c}{n_1.Math.1+n_2.Math.0,1}.Math.d.Math.F_2$

[0147] In order to calculate the antimicrobial activity, the individual results of the live germ count for the plates in each test series were summed up as a simple arithmetical average and from this the log.sub.10 reduction between sample and reference plates was determined.

[0148] The calculation was performed using the following formula:

log.sub.10reduction=log.sub.10(KG).sub.Ref(x)log.sub.10(KG).sub.Pr(x)

where
(KG).sub.Ref(x) is CFU on the reference plates at time x and
(KG).sub.Pr(x) is CFU on the sample plates at time x.

[0149] According to JIS Z 2801:2000, an antimicrobial activity is present at a log reduction of at least 2.0 after 24 hours of reaction time.

[0150] If there were no countable colonies present on the agar plates with the samples at the lowest dilution stage in the pour plate method, the result was stated as <10 CFU/ml in accordance with the requirements in the test standard.

4. Components, Composition, Characterisation and Results of the Dynamic/Mechanical and Antimicrobial Examinations of the Cured products:

TABLE-US-00001 Polyester, vinyl ester urethane, vinyl ester (a) Average molecular weight Mass- Product Antimicrobial efficacy per average Glass Initial reactive molecular Water transition germ Surface germ double Melt weight Component (b) absorption temperature count Reference germ count sample bond Acid value viscosity.sup.II) (Mw) Mole [% by after 7 T.sub.G at 10 Hz (log count after 24 h after 24 h (log Log Composition.sup.I) [g/mol] [mg KOH/g UP] [mPas] [g/mol] Name content weight] days [%] [ C.] CFU/ml) (log CFU/ml) CFU/ml) reduction ITS.sub.1HPN.sub.0.5NPG.sub.0.5 248.3 44.1 90 5,102 TBAEMA 1.34 50 5.98 77.6 5.4 7 2.1 4.9 ITS.sub.1HPN.sub.0.5NPG.sub.0.5 (10,000 TBAEMA 1.64 55 7.00 82 5.4 7 1 6 ITS.sub.1HPN.sub.0.5NPG.sub.0.5 1/s) TBAEMA 2.01 60 7.77 85.2 5.4 7 1.8 5.2 ITS.sub.1HPN.sub.0.5NPG.sub.0.5 TBAEMA 2.49 65 7.74 86.9 5.3 7.3 2.7 4.6 ITS.sub.1HPN.sub.1 298.4 44.4 45 4,178 TBAEMA 1.61 50 8.88 74.5 5.3 7.1 1 6.1 ITS.sub.1HPN.sub.1 (10,000 TBAEMA 1.96 55 9.85 84.4 5.5 7.3 1 6.3 ITS.sub.1HPN.sub.1 1/s) TBAEMA 2.42 60 8.54 67.7 5.5 7.3 1 6.3 ITS.sub.1HPN.sub.1 TBAEMA 3 65 15.61 63.6 5.4 7.3 1 6.3 ITS.sub.1HPN.sub.0.5CHDM.sub.0.5 268.3 31.5 290 8,786 TBAEMA 1.45 50 2.89 88.7 5.3 7.3 1 6.3 (10,000 1/s) ITS.sub.1NPG.sub.0.5CHDM.sub.0.5 218.3 31.7 620 7,894 TBAEMA 1.43 55 2.78 94.1 5.3 7.4 1.3 6.1 ITS.sub.1NPG.sub.0.5CHDM.sub.0.5 (5,000 TBAEMA 1.77 60 4.84 92.1 5.3 7.3 3 4.5 1/s) ITS.sub.1HPN.sub.0.5TCDDM.sub.0.5 294.3 27.1 470 10,069 TBAEMA 2.38 60 3.21 89.2 5.3 7.4 2.9 4.5 (10,000 1/s) ITS.sub.1NPG.sub.0.5TCDDM.sub.0.5 244.3 27.5 700 10,571 TBAEMA 1.61 55 2.87 91.1 5.4 7.7 1 6.7 (2,500 1/s) ITS.sub.1Dianol220.sub.1 410.5 12.8 720 50,230 TBAEMA 3.32 60 68.2 5.3 7.5 1 6.5 (2,500 1/s) ITS.sub.1Dianol220.sub.1 TBAEMA 4.11 65 8.64 67.4 5.3 7.5 1 6.5 ITS.sub.1NPG.sub.1.0 198.3 46.5 260 TBAEMA 2.5 5.89 85.7 5.3 7.7 3.9 3.8 (10,000 1/s) ITS.sub.1NPG.sub.0.9CHDM.sub.0.1 202.3 49.7 280 4,363 TBAEMA 2.5 6.14 93.4 5.3 7.7 3 4.7 (10,000 1/s) ITS.sub.1NPG.sub.0.8CHDM.sub.0.2 206.3 47.3 600 4,434 TBAEMA 2.25 5.73 94.2 5.3 7.7 3.9 3.8 ITS.sub.1NPG.sub.0.8CHDM.sub.0.2 (10,000 TBAEMA 2.5 5.18 91.3 5.3 7.7 3 4.7 1/s) ITS.sub.1NPG.sub.0.7CHDM.sub.0.3 210.3 43.4 970 4,914 TBAEMA 2.5 4.71 87.9 5.3 7.7 4.5 3.2 (10,000 1/s) ITS.sub.1NPG.sub.0.6CHDM.sub.0.4 214.3 42.2 480 6,008 TBAEMA 2.5 4.14 97.3 5.4 7.7 4.2 3.5 (10,000 1/s) ITS.sub.1NPG.sub.0.5CHDM.sub.0.5 218.3 41.7 580 5,901 TBAEMA 2.5 4.21 95.7 5.3 7.7 4.8 2.9 (10,000 1/s) ITS.sub.1NPG.sub.0.4CHDM.sub.0.6 222.3 33.1 900 6,422 TBAEMA 2.5 4.48 91.7 5.3 7.7 5.3 2.4 (2,500 1/s) HPMA.sub.1MDI.sub.1.01TBBHEA.sub.0.5 475.0 DMAEMA 4.53 60 6.79 98.8 5.3 8 2 6 HPMA.sub.1MDI.sub.1.01TBBHEA.sub.0.5 DMAEMA 5.61 65 17.26 92.1 5.3 8 1 7 HPMA.sub.1MDI.sub.1.01TBBHEA.sub.0.5 TBAEMA 2.56 50 1.03 109.2 5.3 8 1 7 HPMA.sub.1MDI.sub.1.01TBBHEA.sub.0.5 TBAEMA 3.13 55 1.37 98.6 5.3 8 1 7 HPMA.sub.1MDI.sub.1.01TBBHEA.sub.0.5 TBAEMA 3.84 60 1.48 106.1 5.3 8 1.1 6.9 HPMA.sub.1MDI.sub.1.01TBBHEA.sub.0.5 TBAEMA 4.76 65 1.96 92.4 5.3 8 1 7 HPMA.sub.1MDI.sub.1.01TBBHEA.sub.0.5 TBAEMA 5.98 70 2.71 97.7 5.3 8 1 7 HPMA.sub.1MDI.sub.1.01DPG.sub.0.5 461.5 DMAEMA 3.59 55 4.89 105.5 5.3 8.1 5.1 3 HPMA.sub.1MDI.sub.1.01DPG.sub.0.5 DMAEMA 5.45 65 11.39 94.3 5.3 8 1 7 HPMA.sub.1MDI.sub.1.01DPG.sub.0.5 DMAEMA 6.85 70 32.76 85.8 5.3 8 1 7 HPMA.sub.1MDI.sub.1.01DPG.sub.0.5 TBAEMA 2.49 50 1.26 104.1 5.3 8.1 1.5 6.6 HPMA.sub.1MDI.sub.1.01DPG.sub.0.5 TBAEMA 3.04 55 1.33 100.2 5.3 8.1 1.2 6.9 HPMA.sub.1MDI.sub.1.01DPG.sub.0.5 TBAEMA 3.73 60 2 99.2 5.3 8.1 1 7.1 HPMA.sub.1MDI.sub.1.01DPG.sub.0.5 TBAEMA 4.63 65 2.21 97 5.3 8.1 1 7.1 HPMA.sub.1MDI.sub.1.01DPG.sub.0.5 TBAEMA 5.81 70 3.65 95.1 5.3 8.1 1 7.1 (1-methyl 256.3 TBAEMA 2.08 60 94.5 5.3 8.1 3.7 4.4 ethylidene)bis [4,1-phenyleneoxy(2- hydroxy-3,1- propanediyl)]-bis methacrylate I) ITS stands for itaconic acid NPG stands for neopentyl glycol TCDDM stands for tricyclodecane dimethanol TBAEMA stands for tert.-butylaminoethyl methacrylate HPMA stands for hydroxypropyl methacrylate TBBHEA stands for tert.-butyl-bis-hydroxyethylamin HPN stands for hydroxypivalic acid neopentyl glycol ester CHDM stands for 1,4 cyclohexane dimethanol Dianol 220 stands for diethoxylated bisphenol A MDI stands for methylene diisocyanate DPG stands for dipropylene glycol II) The apparatus has different shear rates, the shear rate is selected such that the measurement is carried out with maximum sensitivity. The shear rate at which the viscosity was measured is shown in brackets. It can be stated that the problems of the invention can be solved with the products prepared, because: 1. In all the products prepared, a pronounced antimicrobial efficacy can be seen. This is an intrinsically antimicrobial effect. 2. The products all have a glass transition temperature which is suitable for use in a material.