RESIN-CONTAINING COMPOSITION WITH ANTIMICROBIAL PROPERTIES, IN PARTICULAR BIOCIDAL PROPERTIES, FOR SURFACE COATINGS ON PAPER LAYERS OR WOOD-BASED PANELS

Abstract

Provided is a composition having antimicrobial, biocidal properties, in particular antiviral properties, for surface coatings of paper layers or material panels. The composition includes at least one formaldehyde resin, in particular a melamine-formaldehyde resin, at least one compound of general formula (I) R.sup.1SiX.sub.3 (I), where X is alkoxy, and R.sup.1 is an organic moiety selected from the group comprising C1-C10 alkyl, which may be interrupted by —O— or —NH—, and where R.sup.1 has at least one functional moiety Q.sub.1 selected from a group including an amino, methacrylic, methacryloxy, vinyl and epoxy group, at least one further compound of the general formula (II) SiX.sub.4 (II), where X is alkoxy, and at least one antimicrobial agent, in particular at least one biocide.

Claims

1. A resin-containing composition having antimicrobial properties, in particular antiviral properties, for surface coatings of paper layer or wood-based panels, said composition comprising: at least one formaldehyde resin, in particular a melamine-formaldehyde resin, at least one compound of the general formula (I)
R.sup.1SiX.sub.3  (I), where X is alkoxy, and R.sup.1 is an organic moiety selected from the group comprising C1-C10 alkyl which may be interrupted by —O— or —NH—, and wherein R.sup.1 has at least one functional moiety Q.sub.1 selected from a group containing an amino, methacrylic, methacryloxy, vinyl and epoxy group, at least one further compound of the general formula (II)
SiX.sub.4  (II), where X is alkoxy, and at least one antimicrobial agent, in particular at least one biocide.

2. The composition according to claim 1, wherein is selected from a group containing C.sub.1-6 alkoxy, in particular methoxy, ethoxy, n-propoxy, i-propoxy and butoxy.

3. The composition according to claim 1, wherein R.sup.1 of the compound of general formula (I) is selected from a group comprising methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, which may be interrupted by —O— or —NH—.

4. The composition according to claim 1, wherein the at least one functional moiety Q1 of the compound of general formula (I) is selected from a group comprising epoxide, amino and vinyl group.

5. The composition according to claim 1, comprising least one compound of the general formula (I) and at least one compound of the general formula (II), or at least two compounds of the general formula (I) and at least one compound of the general formula (II).

6. The composition according to claim 1, wherein at least one biocide is selected from a group comprising benzalkonium chloride, chitosan, phenylphenol, copper sulphate, 4-chloro-3-methylphenol.

7. The composition according to claim 1, wherein at least two biocides, in particular phenylphenol and 4-chloro-3-methylphenol, are present.

8. The composition according to claim 1, comprising inorganic particles, in particular nanoparticles, preferably based on SiO.sub.2 (silica sol, zeolites).

9. The composition according to claim 1, comprising at least one alkoxytitanate such as Tetraisopropyl orthotitanate (titanium isopropylate) or tetraisobutyl orthotitanate (titanium isobutylate).

10. (canceled)

11. A wood-based panel or paper layer, preferably decorative paper layer or overlay paper layer, coated with at least one resin-containing composition according to claim 1.

12. (canceled)

13. A method for producing a paper layer or wood-based panel provided with an antiviral effect, wherein at least one paper layer or wood-based panel is provided with at least one coating, in particular at least one surface coating, comprising a resin-containing composition according to claim 1.

14. The method according to claim 13, wherein at least one paper layer is a decorative paper layer or overlay paper layer.

15. The method according to claim 13, comprising the following steps: impregnating the at least one paper layer with a resin suspension; applying at least one antivirally active coating comprising a resin-containing composition to at least one impregnated paper layer; and drying of the paper layer with formation of an impregnate.

16. The method according to claim 13, wherein the at least one wood-based panel is a wood chip panel, medium-density fibre (MDF), high-density fibre (HDF) or oriented strand board (OSB), plywood panel or a plastic composite panel (WPC).

17. The method according to claim 13, comprising the following steps: applying at least one decorative layer, in particular in the form of a direct print or a decorative paper layer, to the at least one wood-based panel; applying to the at least one decorative layer at least one antivirally active coating comprising a resin-containing composition comprising: at least one formaldehyde resin, in particular a melamine-formaldehyde resin, at least one compound of the general formula (I)
R.sup.1SiX.sub.3  (I) where X is alkoxy, and R.sup.1 is an organic moiety selected from the group comprising C1-C10 alkyl which may be interrupted by —O— or —NH—, and wherein R.sup.1 has at least one functional moiety Q.sub.1 selected from a group containing an amino, methacrylic, methacryloxy, vinyl and epoxy group, at least one further compound of the general formula (II)
SiX.sub.4  (II) where X is alkoxy, and at least one antimicrobial agent, in particular at least one biocide to the at least one decorative layer; and pressing the layer structure to form a laminate.

18. (canceled)

19. (canceled)

Description

DESCRIPTION OF THE INVENTION

[0134] The proposed solution is explained in more detail below with reference to examples of embodiments.

Example 1: A First Antimicrobial Additive AV-1

[0135] This is an aqueous additive that can be mixed into the resin during production.

[0136] Description of the preparation of the additive AV-1: Preparation of 214 μg glycidyloxypropyltriethoxysilane in a stirred flask. Addition of 9 g of 10% acetic acid. After stirring for 10 minutes at room temperature, 10 g titanium isobutylate is added and stirred for a further 10 minutes. Then 391 g silica sol CS 30 716P is added. The mixture heats up to approx. 60° C. by hydrolysis and is now heated to 80° C. and boiled at reflux. After about 50 minutes, benzalkonium chloride in water (20% solution) is added and 8 g aminoethylaminopropyltriethoxysilane is added. The hyrolysate is boiled for a further 60 minutes at 80° C. under reflux. The mixture is then diluted with a further 85 g of water and a rotary evaporator is used to remove the ethanol produced during the hydrolysis. After removal of the alcohol, the mixture has a flash point of over 85° C. This additive can now be added to the finished melamine resin.

Example 2: A Second Antimicrobial Additive AV-2

[0137] This is an aqueous additive with residual alcohol which can be mixed into the resin during production.

[0138] Description of the preparation of the additive AV-2: Preparation of 59.7 g glycidyloxypropyltriethoxysilane and 10.91 g tetraethoxysilane in a stirred flask. Addition of a mixture consisting of 30.98 g H.sub.2O, 5 g ethanol and 2.24 g para-toluenesulfonic acid. The mixture heats up to approx. 55° C. and is further stirred for approx. 60 minutes. Part of the alcohol formed during the hydrolysis is removed after 12 hours of standing time with the help of a rotary evaporator. The weight of the mixture is thereby reduced by 17 wt. %. To 10 g of this hydrolysate, another 10 g of H.sub.2O and 0.352 g of para-toluenesulphonic acid are now added. With the aid of a dispersing stirrer, 0.51 g of chitosan is now dissolved in this mixture. After a 10-minute stirring time, a transparent, highly viscous additive is obtained, which can now be added to the finished resin.

Example 3: A Third Antimicrobial Additive AV-3

[0139] This is an aqueous additive with residual alcohol which can be mixed into the resin during production.

[0140] Description of the preparation of the additive AV-3: Preparation of 20.0 g glycidyloxypropyltriethoxysilane and 12.8 g tetraethoxysilane in a stirred flask. Addition of a mixture consisting of 18.1 g H.sub.2O, 2 g ethanol and 0.76 g para-toluenesulfonic acid. The mixture heats up to approx. 55° C. and is stirred for approx. 60 minutes. Under reflux the mixture is now heated to 80° C. and after 60 minutes 8.4 g phenylphenol are added to the mixture. The hydrolysate is now boiled at 80° C. for another 60 minutes. Part of the alcohol formed during the hydrolysis is removed after 12 hours by means of a rotary evaporator. The weight of the mixture is reduced by 12 wt. %. A transparent additive is obtained, which can now be added to the finished resin.

Example 4: A Fourth Antimicrobial Additive AV-4

[0141] This is an additive that is produced in the resin (in situ) and therefore cannot be used as a stand-alone additive.

[0142] Description of the preparation of the additive AV-4: 215 g melamine resin (delivered from Heiligengrabe) are placed in a stirring flask. Addition of a mixture consisting of: 8.0 μg glycidyloxypropyltriethoxysilane, 7.1 g tetraethoxysilane as well as 5.2 g aminoethyl-aminopropyltriethoxysilane and a mixture consisting of 12.2 g H.sub.2O, 0.44 g para-toluenesulfonic acid. The mixture is heated to approx. 45 g and stirred for 60 minutes. Then 2.91 g copper sulphate and 9.8 g silica sol CS 20 516 P are added and stirred for another 12 hours. A translucent, slightly bluish modified resin is obtained.

Example 5: A Fifth Antimicrobial Additive AV-5

[0143] This is an additive that is produced in the resin (in situ) and therefore cannot be shipped as a stand-alone additive.

[0144] Description of the preparation of the additive AV-5: Preparation of 215 g melamine resin (delivery from Heiligengrabe) in a stirring flask. Addition of a mixture consisting of: 8.0 μg glycidyloxypropyltriethoxysilane, 7.1 g tetraethoxysilane as well as 5.2 g aminoethyl-aminopropyltriethoxysilane and a mixture consisting of 12.2 g H.sub.2O, 0.44 g para-toluenesulfonic acid. The mixture is heated to approx. 45 g and stirred for 60 minutes. Then 1.99 g copper sulphate and 9.8 g silica sol 200 B 30 are added and stirred for another 12 hours. A translucent, slightly greyish modified resin is obtained.

Example 6: A Sixth Antimicrobial Additive AV-6

[0145] This is an additive that is produced in the resin (in situ) and therefore cannot be shipped as a stand-alone additive.

[0146] Description of the preparation of the additive AV-6: 215 g melamine resin (delivered from Heiligengrabe) are placed in a stirring flask. Addition of a mixture consisting of: 8.0 g glycidyloxypropyltriethoxysilane, 7.1 g tetraethoxysilane as well as 10.4 g aminoethyl-aminopropyltriethoxysilane and a mixture consisting of 12.2 g H.sub.2O, 0.44 g para-toluenesulfonic acid. The mixture is heated to approx. 45 g and stirred for 60 minutes. Then 5.82 g copper sulphate and 22.1 g silica sol CS 20 516 P are added and stirred for another 24 hours. A translucent, slightly bluish modified resin is obtained.

Example 7: Application of the Composition According to the Proposed Solution to a Decorative Paper

[0147] On an impregnation channel, a decorative paper (basis weight: 70 g/m.sup.2, width: 2070 mm) was impregnated in a first impregnation step with an aqueous melamine resin (solids content: 55 wt %) in a quantity of 130 g/m.sup.2. The production speed was 50 m/min. The melamine resin contained the usual additives (hardener, wetting agent, defoamer, etc.).

[0148] The impregnate then passed through a drying channel, where it was dried back to a residual moisture of 15-20%.

[0149] Then, in a second impregnation step, 40 g melamine resin fl./m.sup.2 was applied using an anilox roller. This resin contained 2 wt % antiviral agent on solid resin. The melamine resin had a solids content of approx. 55 wt %.

[0150] The impregnate is then dried again in a flotation dryer. It is dried to a residual moisture content of 5.5-6.0% by weight. The impregnate is then cut to size (2.8 or 5.6×2.07 m) or rolled up. Formats were then pressed onto chipboard in a short-cycle press, with a zero sample without active ingredient in the surface also being tested. The pressing parameters were: Pressing pressure 40 kg/cm.sup.2, pressing temperature: 190° C., pressing time: 15 sec.

[0151] The usual tests specified within the framework of quality assurance were carried out on the coated panels.

TABLE-US-00001 Exam* Zero sample Variant 1 Variant 2 Variant 3 Variant 4 Variant 5 Variant 6 Acid test** Level 1 Level 1 Level 1 Level 1 Level 1 Level 1 Level 1 Scratch test Grade 3 Grade 3 Grade 3 Grade 3 Grade 4 Grade 4 Grade 4 Water-Steam test w/o findings w/o findings w/o findings w/o findings w/o findings w/o findings w/o findings Spot un-sensitivity Level 4 Level 4 Level 4 Level 5 Level 4 Level 5 Level 5 *Apart from the acid test, the tests were carried out in accordance with DIN EN 14323- 2017 July. carried out **Level 1: without findings, Level 2: slight change in gloss level and/or colour Level 3: strong change in gloss level and/or colour

[0152] As can be seen from the table, no abnormalities were found.

[0153] Samples from production were sent to a testing laboratory for “testing of fabrics and materials for antiviral activity with an unenveloped test virus”.

[0154] Thereby, all test samples showed a value of antiviral effect A (log 10 PFU) of >3 (ISO 18184:2014-09 Annex G) when tested according to specifications of ISO 21702:2019-05 “Measurement of antiviral activity on plastic and other non-porous surfaces”. Thus, a significant reduction is achieved for all test samples.

Example 8: Application of the Composition According to the Proposed Solution to an Overlay

[0155] On an impregnation channel, an overlay (basis weight: 25 g/m.sup.2, width: 2070 mm) was impregnated in a first impregnation step with an aqueous melamine resin (solids content: 55 wt %) in a quantity of 135 g/m.sup.2. The production speed was 50 m/min. The melamine resin contained the usual additives (hardener, wetting agent, defoamer, etc.).

[0156] The impregnate then passed through a drying channel, where it was dried back to a residual moisture of 15-20%.

[0157] Then, in a second impregnation step, 40 g melamine resin fl./m.sup.2 was applied using an anilox roller. This resin contained 2 wt % antiviral agent on solid resin. The melamine resin had a solids content of approx. 55 wt %.

[0158] The impregnate is then dried again in a flotation dryer. It is dried to a residual moisture content of 5.5-6.0% by weight. The impregnate is then cut to size (2.8 or 5.6×2.07 m) or rolled up. Formats were then pressed in a continuous press to form a laminate. The following structure was used: [0159] Overlay impregnate with antiviral agent (see above) [0160] Decorative impregnate (paper weight: 70 g/m.sup.2, resin application: 100 wt % melamine resin, VC value: 5.6-6.0%) [0161] Core layer (underlay impregnate NKP; paper weight: 160 g/m.sup.2, resin application: approx. 85% by weight mixed resin, purchased) [0162] Pergamine (paper weight: 50 g/m.sup.2) The pressing parameters were: Feed rate: 8 m/min, pressing pressure 80 kg/cm.sup.2, pressing temperature: 190° C.

[0163] The laminate was then glued to a 38 mm chipboard (adhesive: urea-formaldehyde glue), which had a worktop profile on one side and then the laminate overhang around the glued profile was formed and pressed on in a postforming line.

[0164] The laminate can also be used for vertical applications. A decorative impregnate with an antiviral finish can be used instead of the overlay.

Example 9: Application of the Composition According to the Proposed Solution to an Overlay

[0165] On an impregnation channel, an overlay (basis weight: 25 g/m.sup.2, width: 2070 mm) was impregnated in a first impregnation step with an aqueous melamine resin (solids content: 55 wt %) in a quantity of 135 g/m.sup.2. The production speed was 50 m/min. The melamine resin contained the usual additives (hardener, wetting agent, defoamer, etc.). After the resin application, corundum was sprinkled on the top side of the overlay with a sprinkling device. This was F 230 (FEPA standard). The application quantity was 20 g/m.sup.2.

[0166] The impregnate then passed through a drying channel, where it was dried back to a residual moisture of 15-20%.

[0167] Then, in a second impregnation step, 40 g melamine resin fl./m.sup.2 was applied to the back of the overlay using a grid roller. This resin contained 2 wt % antiviral agent on solid resin. The melamine resin had a solids content of approx. 55 wt %.

[0168] The impregnate is then dried again in a flotation dryer. It is dried to a residual moisture content of 5.5-6.0% by weight. The impregnate is then cut to size (2.8 or 5.6×2.07 m) or rolled up. The formats were then pressed in a short-cycle press to form a floor structure for a laminate floor. The following structure was used: [0169] Overlay impregnate with antiviral agent (see above) [0170] Decorative impregnate (resin application: 100 wt % melamine resin, VC value: 5.6-6.0%) [0171] HDF, 8 mm [0172] Backing impregnate (paper weight: 80 g/m.sup.2, resin application: 120 wt %)

[0173] The pressing parameters were: Pressing pressure 40 kg/cm.sup.2, pressing temperature: 190° C., pressing time: 12 sec.

[0174] The overlay can also be used for a construction for the production of flooring where the HDF has been directly printed. In this case, the overlay is used instead of the final resin application with the antiviral agent.

Example 10: Application of the Composition According to the Proposed Solution to a Wood-Based Panel

[0175] An HDF (format: 2800×2070×7 mm) is first coated with a melamine resin in a direct printing line (application quantity: approx. 20 g melamine resin fl./m.sup.2, solids content: approx. 65 wt. %). The resin is dried in a circulating air dryer and then a colour base coat consisting of titanium dioxide and casein is applied. This colour base coat is applied up to seven times. The application quantity is 5-10 g primer fl./application. After each application, an intermediate drying is carried out with the help of a circulating air and/or IR dryer. Then a primer is applied (application quantity 10-20 g fl/m.sup.2). This is also dried. A decor is then printed onto this primer using gravure or digital printing.

[0176] Then a covering layer of melamine resin is applied (application quantity: 10-30 g melamine resin fl./m.sup.2, solids content: 65 wt %). The melamine resin contains glass beads (diameter glass beads: 80-100 μm, application quantity: 5 g glass beads/m.sup.2) as spacers. The panels again pass through a dryer. They are then cooled in a paternoster.

[0177] The panels are then coated on a production line on the top side with melamine resin (application quantity: 60 g melamine resin fl./m.sup.2, solids: 65 wt %). At the same time, a melamine resin is applied as a backing on the reverse side in the same quantity, also with the help of a roller. Then corundum is sprinkled on the top side of the panel (application quantity: 20 g corundum/m.sup.2, grain size: F230 according to FEPA standard). The structure is aired off or dried in a dryer with the help of IR radiators or circulating air. Subsequently, 30 g melamine resin fl./m.sup.2 (solids content: 60 wt %) is applied twice more with the help of roller application units. Intermediate drying follows after each application.

[0178] In a final roller application, 40 g melamine resin fl./m.sup.2 was applied using a grid roller. This resin contained 2 wt % antiviral agent on solid resin. The melamine resin had a solids content of approx. 55 wt %.

[0179] The panels are dried in a circulating air dryer. The panels are then transferred to a short-cycle press. There the structure is then pressed at T=180° C., p=30 kg/cm.sup.2 and t=14 sec. A press plate with a deckle structure was used.

Example 11: Additive AV-30

[0180] This is an aqueous additive without residual alcohol, which can be mixed into the resin during production. Alcohol can lead to explosion protection problems in various plants above certain concentrations. Furthermore, the processing of large quantities results in requirements due to emission regulations. Therefore, an attempt was made to modify the additive based on AV-3 in such a way that a purely aqueous, non-flammable additive is created.

[0181] Description of the Production of the Additive AV-31:

[0182] Prepare 20.0 g glycidyloxypropyltriethoxysilane and 12.8 g tetraethoxysilane in a stirred flask. Addition of a mixture consisting of 18.1 g H.sub.2O and 0.44 g of an ion exchanger (Lewatit 2629). The mixture is heated to approx. 60° C. and stirred for approx. 120 minutes. Then the ion exchanger is sieved off and the mixture is heated to 80° C. under reflux. After 60 minutes, 10.7 g phenylphenol (approx. 22.4 wt. %) are added and the hydrolysate is now kept at 80° C. for a further 60 minutes after the addition of a mixture of 3.3 g demineralised water, 2.1 g dipropylene glycol monomethyl ether and 0.3 g sodium dodecylbenzosulphonate. The alcohol formed during the hydrolysis is removed after 12 hours standing time with the help of a rotary evaporator (approx. 19 g). The flash point of this additive is now >85° C. This additive can now be added to aqueous melamine resin.

[0183] Production trials have shown that insufficient mixing (e.g. downtimes of the plant or insufficient speed during mixing) can lead to segregation phenomena and thus to optical inhomogeneity, which strongly disturbs the optical appearance of the furniture surface.

[0184] Laboratory tests showed that this is mainly due to the phenylphenol content. The maximum content of phenylphenol without segregation is ≤20 wt. %.

[0185] In order not to reduce the effectiveness of the additive and not to jeopardise production safety, the phenylphenol content was therefore slightly reduced and replaced by another approved biocidal product (4-chloro-3-methylphenol).

Example 12: Additive AV-34+

[0186] Description of the Production of the Additive AV-34+:

[0187] Prepare 20.0 g glycidyloxypropyltriethoxysilane and 12.8 g tetraethoxysilane in a stirred flask. Addition of a mixture consisting of 18.1 g H.sub.2O and 0.44 g of an ion exchanger (Lewatit 2629). The mixture is heated to approx. 60° C. and stirred for approx. 120 minutes. Then the ion exchanger is sieved off and the mixture is heated to 80° C. under reflux. After 60 minutes, 9.56 g phenylphenol (approx. 20 wt. %) and 0.23 g 4-chloro-3-methylphenol (approx. 0.48 wt. %) are added and the hydrolysate is now kept at 80° C. for a further 60 minutes after addition of a mixture of 3.3 g demineralised water, 2.1 g dipropylene glycol monomethyl ether and 0.3 g sodium dodecylbenzosulphonate. The alcohol formed during the hydrolysis is removed after 12 hours standing time with the help of a rotary evaporator (approx. 19 g). The flash point of this additive is now >85° C. This additive can now be added to aqueous melamine resin.

[0188] Laboratory tests showed that this low addition of the 4-chloro-3-methylphenol does not cause any odour nuisance from the new biocide. Only at a concentration above 0.8 wt. % can the 4-chloro-3-metyhlphenol be perceived odourously at processing temperatures above 150° C. Apart from the odour nuisance, we can increase the content of 4-chloro-3-metyhlphenol up to also 28 wt. % without detecting any inhomogeneity.

[0189] Practical tests show that there is now no inhomogeneity in the surface even with longer standing times and segregation could not be observed.

[0190] Antiviral Tests:

[0191] The antiviral compositions were tested for antiviral activity according to ISO 217022:2019-05 “Measurement of antiviral activity on plastic and other non-porous surfaces”.

[0192] The results showed significant antiviral activity for AV-1 to AV-6 with respect to bacteriophage MS2 (DSM 13767) with a log 10 PFU above 4.5.

[0193] A virus reduction of 97.2% was also demonstrated with regard to bovine coronavirus (BoCV).