JPS5827939B2 - Method to reduce the number of viable microorganisms in the system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a substrate and surface that are improved by contacting a substrate that develops a negative charge in water with a substance that ionizes in water to generate cations and anions; physical contact with a viable microorganism, said substance having the formula R8R9R10S+X
sulfonium salt of -, formula o(sicdH2ds+x-)
Sulfonium salt of 2, formula % formula %) Intiuronium salt of R8C(NH2)2+X-, formula 0
(Sr Cd H2d S +C(NH□)2X-)
Inchiuro(CH3)2 nium salt of 2, phosphonium salt of formula R'R5R6R7P+X- and 2〇 (S t Cd ) (2d P +X -
)2 phosphonium salt (CH3)2 (R12)3 (wherein R8, H, 9 and RIO are separately alkyl groups or aryl groups (however, the total number of carbon atoms in the molecule is less than 30) or the formula Y a S iCnH2nb (wherein, Y is a hydrolyzable group, Q is an alkyl group having 1 or 2 carbon atoms or (CH3)3810, the average value of a is 0-3, b is a silyl-substituted alkyl group with an average value of 0-3 and n is an integer of 1 or more, and at least one of R8, R9 and R10 is the above-mentioned silyl-substituted alkyl group, and
- is a water-soluble monovalent anion, and R is separately an alkyl or aryl group (provided the total number of carbon atoms in the molecule is less than 20) or the formula YaSiCnH2o- as defined above.
is a silyl-substituted alkyl group, R4, R5, R6 and R7 have the same meanings as R8+ R9 and RIO above, R11 and R12 are separately alkyl groups or aryl groups (however, the total number of carbon atoms in the molecule is less than 60) ), and d
is an integer greater than or equal to 1.

).

The value of n is usually 1-10.

For practical purposes, the value of d is generally 1-10.

As already mentioned, the size of the alkyl or aralkyl group depends on the type of material used.

For example, when using a sulfonium salt of the formula R8R9R10S+X- or a phosphonium salt of the formula R, RRRPX-, the total number of carbon atoms in the molecule can be up to 30; In this case, a total of up to 20 carbon atoms is required.

Also the substance or formula% formula% honium salt or formula 0(Si(CH3)2CdH2dP+(R12)3X-
) In the case of the phosphonium salt of 2, the total number of carbon atoms in the molecule can be up to 60.

Regarding the latter sulfonium and phosphonium salts, the present invention does not take into account alkyl or aryl groups of 60i11 carbon atoms, but instead disiloxanes containing alkyl or aryl groups on the sulfur or phosphorus atoms, respectively (but not on molecular less than 30 carbon atoms for each sulfur or phosphorus atom in the sulfur or phosphorus atom).

The size and type of alkyl or aryl group are important.

This is because large groups provide a permanent surface modification and, therefore, a permanent bactericidal effect.

Bulky organic cations are basically very strongly adsorbed.

When the organic groups have a linear argyl configuration, these groups tend to be closely packed side by side and extend upwardly from the surface of the substrate in effect.

This closer proximity results in van der Waalska bonding or other similar effects between the alkyl groups.

This increased binding functionality tends to increase the persistence of cationic surfaces.

For purposes of this invention, one or two large alkyl or aryl groups are generally used on the molecule.

For all practical applications, molecules containing more than two large alkyl or aryl groups are difficult to prepare, and furthermore, such molecules are too bulky to provide optimal bonding between the groups for the present invention. It tends to be too much.

Preferred compounds for use in the present invention are those containing at least one alkyl or aryl group having more than 10 carbon atoms.

For purposes of this invention, X- is a water-soluble monovalent anion.

Examples of preferred anions are C1-B'r''-, I- and CI-(3COO-).

The advantage of this newly discovered method is that a very wide range of surfaces (including all substances that develop a negative charge when in contact with water) need not have bactericidal activity in solution, but only in aqueous solution. The point is that it can be modified to have bactericidal activity by treatment with a substance that must be ionized to form cations other than protons.

The most important point in the present invention is that the interface between the surface of the substrate of the present invention and the water must be modified.

This is to be understood as the substrate is not chemically modified.

The interface between the surface of the substrate and the water is modified in the sense that the water adsorbed to the surface is modified.

A substrate falling within the scope of the present invention is any substrate that develops a negative charge on its surface in the presence of water.

For example, fibers, textiles, particulate materials (such as sand, earth, concrete and brick surfaces), wood, plastics and polymers all develop negative charges on their surfaces in the presence of water.

When this surface is treated with a solution of a cationic substance (e.g. a cationic surfactant) as defined later in this specification, this surface causes the hydrogen ions of the adsorbed water to move away from the surface and towards the predominantly water. and are modified to the extent that the cations migrate toward the surface.

One theory is that the cations replace the hydrogen ions of the adsorbed water on the surface of the substrate until the cations become very densely packed, but the present inventor does not intend to support this theory.

Furthermore, if the cationic substance contains appropriate groups (described later herein) in the molecule, this modification is permanent and the sterilization of the substrate surface is maintained.

One of the important aspects of the present invention is that the microorganisms must be brought into physical contact with the modified surface.

For example, if the substrate is a glass bulb treated as described above, and is either water-based or aqueous (e.g. milk), mixing the two and stirring with a spatula for a few minutes will produce the desired effect. Probably.

Similarly, pouring a thin film of beer onto a modified surface (eg polyethylene) may be sufficient to achieve the desired effect.

In a third example, a solution containing the appropriate substance is stirred using a power stirrer at a rate that creates a vortex in the solution.

In the fourth example, a filter (e.g. furnace filter) whose surface has been sterilized by treating contaminated air according to the present invention
Blow in through.

The amount of physical force required depends on each method used.

Once the surface of the substrate is modified, microorganisms that come into contact with this surface are killed.

In some instances, there is no migration of cationic substances into the system, and the adsorbed surface does not undergo erosion or leaching, so the substrate can be used repeatedly without loss of effectiveness. Any substrate that develops a negative charge in water is encompassed within the scope of the invention.

Properly treated surfaces are essentially immune to attack by microorganisms.

This surface in a system where microorganisms are growing has no apparent effect on the microorganisms in the system, but microorganisms that come into contact with this surface are killed.

All microorganisms can be killed by agitating the system and bringing them into contact with this surface.

Without agitation, a significant number of microorganisms will not be killed, but the surface will be protected from microbial attack.

That is, a preservative effect within the scope of the present invention can be obtained.

Substrates that develop a negative charge in water at a pH of about 10 or less are suitable for the method of the invention.

Such substrates may include all known textile fibers (e.g. cotton,
cellulose acetate, polyester, nylon, wool, rayon, acrylon, etc.), all known organic surfaces (
Examples include paints, polystyrene, silicone polymers, wood,
(rubber, etc.), includes almost all inorganic surfaces (including, for example, silica, sand, earth, silicate minerals, alumina, glass, water-insoluble concrete and brick surfaces, etc.).

Substances capable of sterilizing such substrates are inthiuronium salts, sulfonium salts and phosphonium salts.

This material does not need to have bactericidal activity in solution, nor does it need to have any effect on the degree of bactericidal activity of the substrate surface treated with this material in solution.

Cations containing bulky organic substituents adsorb more strongly to surfaces.

Such cations do not result in a more active surface, but they do result in a surface that is more resistant to loss of activity due to loss of cations from the surface.

Cations containing silyl-substituted organic substituents have unique advantages over other cations.

A cation having a substituent such as (CH30)3SI- undergoes 7) Hinaga decomposition and polymerization to form a substantially irreversible bond.

The manner in which these materials are placed on the substrate surface is of some importance.

It may be sprayed, dipped, painted or rolled onto the cationic material, and may be dispersed in the case of particulate solids or by soaking techniques in the case of fibers.

The time for contacting the cationic substance with the substrate must depend on the type of substrate and cationic substance used.

For example, in the case of fibers, they should not be treated for long periods of time unless the inner surface of the fibers is to be treated.

Contact times can be from several seconds to several hours.

The required contact time is the time required for the exchange of hydrogen ions and cations of adsorbed water on the surface.

When actually performing a treatment, it may be preferable to rinse the surface of the substrate after the treatment.

The time required to rinse the surface is not critical.

Water is generally used for this purpose, but water and organic solvents can also be used.

For example, rinsing with a mixture of alcohol and water followed by rinsing clean with water is generally sufficient.

Some of the advantages of the method according to the invention are listed below.

The materials selected for use in the present invention are non-hazardous compounds and are not found to be toxic, corrosive or hazardous.

Nor does the compound need to be a biologically hazardous substance.

Very small amounts of substances can be used to kill a seemingly infinite number of microorganisms that come into contact with appropriately treated surfaces.

There is no need to introduce any substances into the system where the microorganisms are present.

Therefore, an extremely strong bactericidal effect can be obtained without contaminating the system with bactericidal agents.

Properly treated surfaces can kill most diverse microbial spectrum.

To enable those skilled in the art to better understand and appreciate the present invention, the following examples are now included.

The following examples will provide the necessary guidance to those skilled in the art in implementing the invention.

Example 1 Paint on technique (Paint onT) on multiple substrates
echn 1que).

This method uses a known amount of a chemical solution to wet the solid.

When the solvent evaporates, the amount of chemical in solution precipitates onto the solid surface.

The so-called powder test (The Powder T
The surprising results obtained by mechanically mixing the pulverized powder and the culture of microorganisms in e5t) are shown in Table 2.

Powder tests range from 0.1 to 0.0, depending on the particle size and density of the finely divided solids. ! Measure out 1 liter and put it into a clean test tube.

Samples treated with chemicals using the paint-on technique and untreated samples of the same size were mixed externally for 15 seconds each using a Vortex mixer).
, place in a 37°C incubator for 30 minutes.

Each sample is then stirred for 10 seconds with 10 ml of sterile broth.

Transfer 0.1 ml of this meat juice to an agar medium and culture for 18 hours.

Thereafter, the number of viable microorganisms extracted from the treated sample is compared with the number extracted from the untreated sample.

The % reduction in viable cells is calculated from the difference between these two numbers.

In other words, if no living microorganisms are extracted, the sample can be said to have achieved 100% sterilization.

This technique allows evaluation of bactericidal activity in relatively small volumes and large surface areas.

The data in Table Ⅰ is for Escherich cells cultured for 18 hours.
A 1:100 dilution of iacoliB was added in 0.1 ml. Obtained using

Samples are often washed and extracted with water before being subjected to powder testing.

As a typical example, about 1 g of sample is thoroughly mixed with about 10 ml of distilled water, and the mixture is filtered or centrifuged and suction dried in a vacuum filter.

In some cases, samples are washed in this manner multiple times.

Table 2 lists the following compounds (the test numbers correspond to the test numbers in the table).

The data shown in Table Ⅰ revealed a number of unexpected effects.

What is most surprising is that all the substances tested were bactericidal in the powder test.

This is most surprising considering that many substances have little or no bactericidal activity in solution.

Perhaps the most widely standardized method for determining the bactericidal activity of any substance is the sterile tube dilution method (Serial T
uber DiIlution).

In this technique, 1 g of material is added to 9 rrl in a sterile glass tube.
Mix with l of sterile meat broth.

1 ml of this mixture was transferred under aseptic conditions to a second tube containing 97111 broth and 1 ml of the test substance 1710
Make a 0 dilution.

This series of operations is repeated while increasing the dilution rate by 10 times.

That is, 1/10, 1/100.1/1000, 1
/10.000 etc.

Choose a meat juice that contains vitamins, amino acids, sugars, etc. (choose the juice that is most suitable for the growth of the microorganisms used in the test).

Each series of tubes is inoculated with approximately 0.1 ml of the test organism and incubated for 24 hours at 37°C for bacterial growth and 25°C for fungal growth.

After culturing, the concentration of the substance with the highest dilution rate that inhibits the growth of microorganisms is determined as the Minimum Inhibitory Concentration (Minimum Inhibitory Concentration).
MIC).

This value is usually PPM (per hundred parts) or μg/7d (
In other words, it is the weight part in the meat juice).

In most of the tests in Table 1, the amount of test substance in the powder test dissolves from the substrate and enters the medium.
This was insufficient to kill ol i-B.

Calculating the number of grams of substance for the unwashed sample (assuming complete dissolution in 0.1ff17 medium) shows that the solution does not reach the MIC of the substance.

I don't know how much material there is after washing, but it is necessarily less.

Example 2 (CH30)3S1(C■■2)3SC(NH2)2+
C4- is mixed with water and this mixture is
Aerosi 1200 silica manufactured by SA Co., Ltd. (Thus, the Aerosi 1200 is treated in an aqueous solution.

Homogenize this using a blender for 5 minutes.

This material is then dried in a 90°C oven for 10-15 minutes.

Next, the silica was prepared using the following method.
Polyethylene oxytosdarate with units CIJ2CH20.

Heat both parts A and B separately to 75℃, then stir until a creamy and smooth substance is obtained, then add B to A.
Add to.

Gradually cool the material with stirring until it stands up, then cool to room temperature without stirring.

Get this cold cream from CTFA CosmeticJ
It is evaluated by the method described in "Evaluation Method for Determining Preservative Efficacy", Vol.

Briefly, a sample of the cream is challenged with microorganisms, and the sample is incubated at 37° C., and the presence or absence of microorganism growth is observed every day.

The results of this test are listed in Table ■.

Similar results can be obtained.

Claims (1)

[Scope of Claims] 1. A surface of a substrate that has been modified by bringing a substrate that develops a negative charge in water into contact with a substance that ionizes in water to generate cations and anions, and a viable microorganism in the system. in physical contact with the substances having the formula [wherein R8, R9 and R10
is separately an alkyl group or an aryl group (provided that the total number of carbon atoms in the molecule is less than 30) or a compound of the formula YasICnH
2n- (wherein b Y is a hydrolyzable group, Q is an alkyl group having 1 or 2 carbon atoms or (CH3) 3810, the average value of a is 0-3, and the average value of b The value is O-3 and n
is an integer of 1 or more), and at least one of R8, R9 and R10 is the above silyl-substituted alkyl group, and X- is a water-soluble monovalent anion; , R is separately an alkyl or aryl group (provided the total number of carbon atoms in the molecule is less than 20111) or the formula YaSiCnH2n- as defined above, R' + R5rb R6 and R7 are the same as R8, R9 and RIO above and R11 and R12 are independently alkyl or aryl groups (with the total number of carbon atoms in the molecule being less than 60), and d is an integer of 1 or more. A method for reducing the number of microorganisms, characterized by: