WO2002032989A1 - Antimicrobial methacrylic polymer material and shaped articles obtained from same - Google Patents

Abstract

The invention concerns an antimicrobial methacrylic polymer comprising a matrix formed of thermoplastic methacrylic polymer or copolymer material, consisting, by weight, of: 80 to 100 %, preferably 90 to 99.5 % of methyl methacrylate monomer units and 0 to 20 %, preferably 0.5 to 10 % of units derived from monoethylenically unsaturated comonomer(s) compolymerisable with the methyl methacrylate monomer and, dispersed in said matrix, at least two antibacterial agents consisting of (A) at least a halogenated phenoxy compound and (B) at least a thiazolinone, isothiazolinone and/or sulphonylpyridine compound, the amount in agents A + B being, by weight, from 20 ppm to 20000 ppm and the weight ratio in agent A and agent B being 0.02 to 50, preferably 0.1 to 10. The invention is useful for making antimicrobial cast or extruded plates, in particular for use in the field of sanitary ware.

Description

 ANTIMICROBIAL METHACRYLIC POLYMER MATERIAL AND SHAPED ARTICLES

OBTAINED FROM THIS MATERIAL DESCRIPTION

The invention relates to methacrylic antimicrobial polymeric materials comprising a matrix formed of thermoplastic methacrylic polymer or copolymer material mainly containing units derived from the methyl methacrylate monomer and at least two specific antimicrobial agents, these (co) polymeric materials exhibit effective protection. especially against bacteria, mold

(mushrooms) and algae; they make it possible to manufacture shaped articles exhibiting this protection, in particular plates, and very particularly plates useful for forming thermoformed sanitary articles, such as baths, sinks, shower trays, sinks, shower stalls, basins, etc. These shaped articles must, in addition, retain the properties inherent in the methacrylic (co) polymer material, that is to say the mechanical, thermal, resistance to solvents, thermoforming capacity, good resistance to aging and the optical properties.

Methacrylic (co) polymers, mainly containing units derived from the methyl methacrylate monomer are thermoplastic polymers increasingly used because of their exceptional optical properties (gloss, very high transparency with at least 90% light transmission in the visible ), their hardness, their ability to be pigmented, to be thermoformed, their resistance to aging, corrosion and atmospheric agents and the ease with which they can be transformed (cutting, polishing, gluing, folding).

These methacrylic (co) polymers can be in the form of beads or granules allowing the manufacture of shaped articles by molding, in particular by extrusion, injection, compression, etc., or else in the form of plates.

Methacrylic (co) polymer plates can be obtained by extrusion or by casting.

To obtain plates according to the cast process, a polymerizable composition is used which mainly contains methyl methacrylate monomer (or a syrup formed from methyl methacrylate prepolymer and methyl methacrylate monomer) and, optionally, copolymeric comonomers with methacrylate methyl. This composition is introduced into a mold consisting of two glass plates separated by a polymer seal (polyvinyl chloride, for example) which ensures the seal and whose thickness determines the thickness of the polymer plate. The mold is placed in a ventilated oven or in a heated swimming pool to allow the polymerization of the monomers. At the end of polymerization, the plate is recovered in methacrylic (co) polymer by demolding. Methacrylic (co) polymer plates find use particularly in the sanitary field. Sanitary shaped articles are generally obtained by thermoforming of methacrylic (co) polymer plates manufactured by the cast process.

On shaped articles, obtained from methacrylic polymer (or copolymer) materials, when used under unhygienic conditions, bacteria, fungi, algae, etc. can develop, which it is necessary to reduce or even 'eliminate; this is particularly the case with shaped articles used in the sanitary field.

It is therefore desirable to find methacrylic polymeric materials from which it is possible to manufacture shaped articles, in particular plates, preferably obtained by casting process, having effective protection in particular against bacteria, fungi and algae, while preserving in particular their mechanical, thermal and optical properties, resistance to solvents, ability to thermoform and good resistance to aging. The antimicrobial methacrylic polymer material according to the invention, which has these characteristics, comprises

I - a matrix formed of thermoplastic methacrylic polymer or copolymer material, formed, by weight, from 80 to 100%, preferably from 90 to 99.5% of methyl methacrylate monomer units and from 0 to 20%, preferably from 0 , 5 to 10% of units deriving from monoethylenically unsaturated comonomer (s) copolymerable (s) with the methyl methacrylate monomer and,

II - dispersed in this matrix, at least two bacterial agents consisting of (A) at least one halogenated phenoxy compound and (B) at least one thiazolinone, isothiazolinone and / or sulfonylpyπdine compound, the amount of agents A + B being , by weight, from 20 ppm to 20,000 ppm and the weight ratio of agent A and agent B being from 0.02 to 50, preferably from 0.1 to 10.

The antimicrobial methacrylic polymer material preferably comprises from 100 ppm to 10,000 ppm of antimicrobial agents (A + B), the remainder consisting of the matrix formed by the methacrylic (co) polymer material. These antimicrobial agents must provide at least one of the desired properties, that is to say protection against bacteria, fungi, algae

The halogenated phenoxy compound (A) is, in particular, 2,4,4'-trιchloro-2'-hydroxy-diphenyl ether

The compound (B) can be a thiazolinone, an isothiazolinone and / or a sulfonylpyπdine compound. As thiazolinone compound, l, 2-benzothιazolιn-3-one can be used; as isothiazolinone, 5-chloro-2-methyl-4-ιsothιazolιn-3-one, 2 methyl- 4-ιsothιazolιn-3-one or 2-n-octyl-4-ιsothιazolιn-3-one. We prefer to use the latter isothiazohne. As the sulfonylpyπdine compound, 2,3,5,6-tetrachloro-4- (methylsulfonyl) -pyπdιne (TMSP) or 2,3,5-tπchloro-4-propylsulfonylpyπdιne can be used.

The methacrylic (co) polymer material constituting the matrix (I) is advantageously formed by weight from 80 to 100%, preferably from 90 to 99.5%, of units derived from the methyl methacrylate monomer and from 0 to 20 % and preferably from 0.5 to 10% by weight of units deriving from monoethylenically unsaturated comonomer (s) copolymeric (s) with the methyl methacrylate monomer.

These monoethylenically unsaturated comonomers copolymerizable with the methyl methacrylate monomer are especially chosen from acrylic, methacrylic and vmylaromatic monomers.

Mention may be made, as acrylic monomers, of acrylic acid, allyl acrylates in which the alkyl group has from 1 to 8 carbon atoms (such as n-butyl, ethyl, 2-ethylhexyl acrylate, isobutyl), hydroxyalkyl or alkoxyalkyl acrylates, in which the alkyl group has from 1 to 4 carbon atoms, acrylamide, acrylonitrile.

As methacrylic monomers, mention may be made of methacrylic acid, alkyl methacrylates in which the alkyl group has from 2 to 10 carbon atoms (such as ethyl methacrylate, isobutyl, secondary butyl, tertiary butyl) , isobomyl methacrylate, methacrylonitrile, hydroxyalkyl or alkoxyalkyl methacrylates in which the alkyl group has from 1 to 4 carbon atoms.

As vmylaromatic monomers, mention may be made of styrene, substituted styrenes (such as α-methyl-styrene, monochlorostyrene and tert.-butyl-styrene).

The methacrylic (co) polymer material which must form the matrix (I) can be obtained by any known method, for example by suspension or bulk polymerization. It can then be in the form of granules or pearls.

The pearls are obtained by the well-known process of polymerization in aqueous suspension of the monomer (s) in the presence of an initiator soluble in the monomer (s) and of a suspending agent. The granules can be obtained from these beads which are melted in an extruder to form rods; these are then cut into granules The granules can also be prepared by bulk polymerization, a well-known process, consisting in polymerizing the monomer (s) or else a prepolymer syrup dissolved in the monomer (s), by presence of an initiator and a chain transfer agent to control the molecular weight of the polymer. The polymer obtained is forced at the end of the line into a die to obtain rods which are then cut into granules. The antimicrobial methacrylic (co) polymer material according to the invention can be obtained by mixing the methacrylic (co) polymer material, for example in the form of pearls or granules, and antimicrobial agents, the latter possibly being in the form of a masterbatch and, optionally other additives such as dyes, pigments and / or UV stabilizers. This mixing can be carried out in any suitable device, for example in an extruder. The mixture is then in the form of granules which can be used to manufacture shaped articles for example by extrusion, injection, compression or any other known shaping process. These shaped articles can be in the form of plates or products of various shapes.

The antimicrobial (co) polymer material according to the invention can also be obtained from a polymerizable composition comprising (a) a polymerizable element mainly comprising a methyl methacrylate component and, (b) dissolved in this polymerizable element or in the component methyl methacrylate, at least two antimicrobial agents, these agents consisting of (A) at least one halogenated phenoxy compound and (B) at least one thiazolinone, isothiazolinone and / or sulfonylpyπdine compound

The polymerizable element advantageously comprises, by weight, from 80 to 100%, preferably from 90 to 99.5%, of methyl methacrylate component and from 0 to 20% and, preferably, from 0.5 to 10% by weight. weight of monoethylenically unsaturated comonomer (s) copolymerable (s) with the methyl methacrylate monomer, such as those mentioned above.

The polymerizable element of said polymerizable composition can also comprise other additives copolymerable or not with the methyl methacrylate monomer. The content of additives can be determined with respect to the methyl methacrylate component or with respect to the polymerizable composition.

The methyl methacrylate component is generally formed, by weight, from 85 to 100% of methyl methacrylate monomer and from 0 to 15% of a methyl methacrylate prepolymer having a conversion rate of 0.06 to 0.15.

When the methyl methacrylate component is formed from a mixture (also called syrup) of methyl methacrylate monomer and methyl methacrylate prepolymer, it is advantageous for this mixture (or syrup) to have a viscosity of 100 to 500 mPa.s , preferably from 200 to 400 mPa.s so as to facilitate the implementation of the casting process (processability) The syrup is prepared in a known manner, by partial polymerization of methyl methacrylate up to a conversion rate of 0.06 to 0.15

As additives which are copolymeric with the methyl methacrylate monomer, other than the monoethylenically unsaturated comonomers mentioned above, it is possible in particular to use at least one polyfunctional crosslinking agent. As polyfunctional crosslinking agent (s) copolymerizable with the methyl methacrylate monomer, mention may be made of polyfunctional monomers polyacrylates and polymethacrylates of polyols, such as diacrylates or dimethacrylates of alkylene glycol (such as diacrylates or dimethacrylates of ethylene glycol, of 1,3-butylene glycol, of 1,4-butylene glycol), polyfunctional vinylbenzene monomers (such as divinylbenzene or tπvinylbenzene), vinyl acrylate or methacrylate, allyl esters, such as methacrylate or allyl acrylate. Thus, this agent or these agents can be used in an amount by weight relative to the methyl methacrylate component, from 0 to 0.2%, preferably 0.01 to 0.1%.

For the polymerization of the polymerizable element, there is advantageously added to said element, at least one usual radical polymerization initiator, such as an azo or peroxide compound, such as the azobis-isobutyronitrile compounds, dibenzoyl peroxide, tertiary peroxide. butyl, isobutyl peroxide, etc. These compounds can be used in an amount by weight of 0 to 0.2%, preferably from 0.002 to 0.2%, very particularly from 0.01 to 0.2% relative to the methyl methacrylate component.

Like other additives which cannot be polymerized with the methyl methacrylate monomer, the polymerizable element can contain, in particular, at least one chain transfer agent, at least one release agent, at least one antioxidant agent and at least one pigment and / or dye. .

Chain transfer agents (or chain limiting agent) make it possible to control the molecular mass of the polymer obtained from the composition. They are alkyl- or arylmercaptans, such as octylmercaptan, laurylmercaptan, t-dodecylmercaptan, polymercaptans, polyhalogen compounds, monoterpenes, such as terpinenes, monounsaturated diterpenes, thioglycolic acid and isooctyl thioglycolate. This or these compound (s) are advantageously added in an amount of 0 to 0.2%, preferably from 0.01 to 0.1% by weight relative to the methyl methacrylate component. The polymerizable composition can also contain pigments or dyes, such as titanium dioxide, calcium carbonate, calcium sulfate, barium sulfate, carbon black. Generally, they are added to the polymerizable composition in the form of a paste comprising a plasticizer, for example alkyl phthalate, in which they are dispersed in a homogeneous manner This or these pasta (s) are advantageously added at a rate of 0 to 5 %, preferably from 0.1 to 5% and very particularly from 0.5 to 2% by weight relative to the polymerizable composition.

Other usual compounds can be added such as a release agent, antioxidants, UV-absorbing agents, etc., in an amount of 0 to 0.2%, preferably 0.01 to 0.1% by weight relative to to the methyl methacrylate component. Other additives can be used depending on the intended application. According to this embodiment, the polymerizable composition to be used for the manufacture of the antimicrobial (co) polymer material according to the invention comprises at least two antimicrobial agents dissolved in the polymerizable element or in its methyl methacrylate component. These antimicrobial agents comprise at least one halogenated phenoxy compound (A) and at least one thiazolinone, isothiazolinone and / or sulfonylpyπdine compound (B) and are those mentioned above. These compounds are used, in the polymerizable composition, in an amount of 20 ppm to 20,000 ppm, preferably from 100 ppm to 100,000 ppm. They can be added together or separately to the polymerizable element in the form of solution (s) in a plasticizer system common to the antimicrobial agents used, for example a tπarylphosphate, such as tπaryl phosphate isopropylated, tπxilyl phosphate (TXP), dioctylphthalate (DOP ), dioctyladipate (DOA), to facilitate their dissolution in the polymerizable element. The weight ratio of agent A and agent B is advantageously from 0.02 to 50, preferably from 0.1 to 10.

The polymerizable composition which can be used in the invention is prepared by dissolving the antimicrobial additives (or their solution (s)) in the polymerizable element comprising the methyl methacrylate monomer (or the syrup formed from methyl methacrylate and a prepolymer of methyl methacrylate) and the other desired additives or they are dissolved in the methyl methacrylate component, then the other additives are added.

The polymerization of the polymerizable composition which can be used in the invention can take place by the known process known as casting. A shaped product is then obtained directly in the form of a plate. As indicated above, the polymerizable composition is introduced into a mold formed by two glass plates separated by a seal (or rod) made of polyvinyl chloride for example. The mold is placed in a ventilated oven in order to follow the polymerization cycle which includes a polymerization step at a temperature of the order of 70 ° C to obtain a conversion rate of approximately 95%, then a post-polymerization step at a temperature of the order of 120 ° C. After cooling, the plate obtained is removed from the mold. The plates obtained have a thickness which corresponds to the thickness of the rod.

These plates can be used as glazing, noise barriers, etc. or be transformed into various articles by thermoforming, cutting, polishing, gluing, folding.

These plates are particularly suitable for making sanitary articles (baths, sinks, shower trays, etc.). To manufacture such shaped articles, the plates can be thermoformed. For this, they are heated to temperatures of at least 140 ° C to obtain their softening. The heating time necessary for complete softening depends on the thickness of the plate and the heating means. Then the softened plate is fixed on the edges of a mold in which the vacuum is created to allow the plate conforming to the shape During thermoforming, the thickness of the plate, which is initially 3 to 8 mm for example, can be reduced to a value between less than 1 mm and 4 mm.

The following examples illustrate the invention; the following compounds are used in the examples.

»MAM: methyl methacrylate

»ABu ^• butyl acrylate (comonomer)

AIBN. azobisisobutyronitπle (initiator)

»BDMA: 1,4-butanedιol dimethacrylate (crosslinking agent) The antimicrobial activity (antibacterial and anti-fungus) indicated in the examples was measured on plates using the following methods for monitoring the anti-bacterial activity or antimycotic of finished textiles and other materials.

* SN 195920: control of antibacterial activity: agar diffusion test.

»SN 195921 ^• control of antimycotic activity: agar diffusion test.

Example 1: a cast plate for sanitary product is prepared

1) Polymerizable element

The polymerizable element is prepared by adding to 100 parts by weight of a syrup (this syrup is formed from 10 parts by weight of methyl methacrylate prepolymer (conversion rate of 0.1) and of MMA (90 parts by weight ):

- 0.07 part by weight of AIBN (initiator)

0.04 parts by weight of BDMA (crosslinking agent)

- 0.05 part by weight of gamma-terpinèπe (chain transfer agent)

- 0.02 parts by weight of antioxidant agent (Tinuvin P ^{® product} sold by Gba- Ceigy)

2) Preparation of the polymerizable composition

In 99 parts by weight of the above polymerizable element, 1 part by weight of a mixture of 2,4,4'-trιchloro-2'-hydroxy-dιphenyl ether and 2-n-octyl-4-ιsothιazolιne is dissolved. - 3-one in solution in dioctylphthalate (DOP). This mixture is sold under the trade name "Sanitized PL 91-35" by the company Claπant

1.4 parts by weight (relative to the polymerizable composition) of pigment paste based on Tι02 and stearic acid are added. 3) Polymerization

The polymerizable composition obtained in (1) is introduced into a mold formed by two glass plates (500 x 300 mm) separated by a polyvinyl chloride joint to obtain a plate with a thickness of 4 mm

The mold is placed in a ventilated oven. The composition is polymerized for 5 hours at 70 ° C. A conversion rate of around 95% is obtained; then heated to 120 ° C for 1 hour. After cooling the mold, the plate is recovered.

We measure, as indicated above, antibacterial and anti-fungal activity. The results are shown in the table.

4) Thermoforrnaqe

The plate obtained is thermoformed in the form of a bathtub, as indicated above, without breakage. We also measure, as indicated above, the antibacterial and anti-fungal activity. The results are shown in the table.

Example 2

The procedure is as in Example 1, but to 99 parts by weight of polymerizable material, 1 part of a mixture of 2,4,4'-tπchloro-2'-hydroxy-dιphenyl ether and 2.3 is added, 5,6-tetrachloro-4- (methylsulfonyl) -pyrιdιne (TMSP) in solution in a phosphate-based plasticizer. This mixture is sold under the trade name "Sanitized PL 98-36" by the company Claπant.

Antibacterial and antimycotic activity is measured, as indicated above. The results are shown in the table.

Example 3: witness

The procedure is as in Example 1, but a polymerizable composition using no antimicrobial agent is used. We measure, as indicated above, the antibacterial and anti-fungal activity. The results are shown in the table.

Claims

REVENDICA TIONS 1) Methacrylic antimicrobial polymer material comprising: I - a matrix formed of thermoplastic methacrylic polymer or copolymer material, formed, by weight, from 80 to 100%, preferably from 90 to 99.5% of methyl methacrylate monomer units and from 0 to 20%, preferably from 0 , 5 to 10% of units deriving from monoethylenically unsaturated comonomer (s) copolymerable (s) with the methyl methacrylate monomer and II - dispersed in this matrix, at least two antibacterial agents consisting of (A) at least one halogenated phenoxy compound and (B) at least one thiazolinone, isothiazolinone and / or sulfonylpyπdine compound, the amount of agents A 4- B being, in weight, from 20 ppm to 20,000 ppm and the weight ratio of agent A and agent B being from 0.02 to 50, preferably from 0.1 to 10 2) Material according to claim 1 characterized in that the (s) comonomer (s) with monoethylenic unsaturation is (are) choιsι (s) among acrylic, methacrylic and vinylaromatic monomers 3) Material according to one of claims 1 and 2, characterized in that the material (co) polymer forming the matrix I is crosslinked. 4) Material according to one of claims 1 to 3, characterized in that the halogenated phenoxy compound (A) is 2,4,4'-tπchloro-2'-hydroxydιphenyléther and the compound (B) is chosen from the group formed by i, 2-benzothιazolιn-3-one, 5-chloro-2-methyl-4- ιsothιazolιn-3-one, 2-methyl-4-ιsothιazolιn-3-one and 2-n-octyl- 4-ιsothιazolιn-3-one 5) Material according to one of claims 1 and 2 and 4, characterized in that it is in the form of granules or beads. 6) Material according to one of claims 1 to 4, characterized in that it is in the form of plates 7) A method of manufacturing the material according to claim 5, characterized in that granules or beads of methacrylic polymer (co) material, the antimicrobial agents A and B are mixed in the form of a master mixture and, optionally other additives 8) A method of manufacturing the material according to claims 6, characterized in that a polymerizable composition is polymerized comprising (a) a polymerizable element comprising by weight, from 80 to 100%, preferably 90 to 99.5% of methacrylate component of methyl and from 0 to 20%, preferably from 0.5 to 10% of comonomer (s) with monoethylenic unsaturation copolymeπsable (s) with the methyl methacrylate monomer, and (b) dissolved in this polymerizable element or in the component methyl methacrylate, at least two antimicrobial agents consisting of (A) at least one halogenated phenoxy compound and (B) at least one thiazolinone, isothiazolinone and / or sulfonylpyπdine compound, the quantity of agents A + B being from 20 to 20,000 ppm by weight and the weight ratio A / B being from 0.02 to 50. 9) A method according to claim 8, characterized in that the polymerizable element further comprises, by weight, relative to the amount of methyl methacrylate component, from 0 to 0.2%, preferably 0.002 to 0, 2% of polymerization initiator, from 0 to 0.2%, preferably from 0.01 to 0.1% of polyfunctional crosslinking agent (s), from 0 to 0.2%, preferably from 0.01 to 0.1% chain transfer agent, from 0 to 0.2%, preferably from 0.01 to 0.1% of release agent, from 0 to 0.2%, preferably from 0.01 to 0.1% of adsorbent UV and from 0 0.2%, preferably 0.01-0.1% antioxidant. 10) Process according to claim 8, characterized in that the polymerizable composition comprises from 0 to 5%, preferably from 0.1 to 5% by weight of paste containing a pigment and / or dye. 11) Shaped article obtained by extrusion, injection or compression of the material according to claim 5. 12) Shaped article obtained by thermoforming of a material according to claim 6.