JPH08311185A - Copolyester excellent in antimicrobial property - Google Patents

Abstract

PURPOSE: To obtain a copolyester having suppressed degrees of polymer discoloration and gel generation, improved heat resistance, useful as a molding material for an antimicrobial fiber, an antimicrobial film, etc., excellent in antimicrobial properties. CONSTITUTION: This copolyester contains a phosphonium salt of a sulfonic acid as a substitutent group in a part of a dicarboxylic acid component and a least one metal selected from the group consisting of Mg, Ca and Mn. The copolyester contains 20-200ppm calculated as phosphorus of the total of phosphoric acid and/or its derivative and has the ratio of the total number of mols of P to the total number of mols of the metal of 0.4-1.0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymerized polyester resin in which a part of dicarboxylic acid has a phosphonium salt of sulfonic acid as a substituent as an antibacterial component.

[0002]

2. Description of the Related Art At present, many antibacterial agents are used in various fields such as industrial, agricultural, and food related fields. For example, natural materials such as chitin and chitosan; titanium dioxide ultrafine particles, silver-containing zeolite, etc. Inorganic materials; various synthetic materials are widely used. Of these, synthetic materials are superior in antibacterial performance compared to natural materials and inorganic materials, but since the antibacterial component is added by the surface treatment method, the antibacterial component may volatilize or be separated, Furthermore, it is accompanied by the problem that toxicity is generally high. The reason why synthetic materials have such high toxicity is that they are highly soluble in water, organic solvents, and the like. Therefore, recently, development of immobilized antibacterial agents which are insoluble and have low toxicity has been promoted.

This fixed antibacterial agent is a polymer type antibacterial agent in which an antibacterial component is fixed to a polymer chain of polyester, polyvinyl or the like. As an antibacterial component, a quaternary ammonium salt (JP-A-54-86548, JP-A-61-24)
Nitrogen-containing compounds such as No. 5378) are well known, but in addition, a phosphonium salt compound is known as a compound having a broad antibacterial spectrum against bacteria, fungi, algae, etc. (JP-A-57-204286). No. JP-A-63-6
0903, JP-A-62-114903, JP-A-1-
93596, JP-A-2-24090).

Japanese Unexamined Patent Publication No. 5-310820 discloses an immobilized antibacterial agent containing the phosphonium salt compound. Specifically, it is an antibacterial material in which an antibacterial component in which a phosphonium salt is ionically bonded to an acidic group (for example, a monomer having a sulfonic acid group) is immobilized on a polymer substance, and the antibacterial material is rubber, plastic, fiber, It is expected to give excellent antibacterial properties by molding into films, paints, etc. In the examples of the publication, a polyester copolymer containing an antibacterial component obtained by reacting a phosphonium salt of sulfoisophthalic acid with tri-n-butyldodecylphosphonium chloride is mentioned. When the present inventors actually produced a molded article such as a fiber or a film based on this example, an increase in the molecular weight was not observed, probably because the content of the phosphonium salt was high, and it was difficult to obtain a predetermined strength. Met. The reason is, as will be described later, in spite of the fact that the content of the phosphonium salt is an important factor for imparting a sufficient viscosity in the molding process, the above publication pays no attention to such quantitative control. It is thought to be based on the fact that it has not been paid. Further, it was also found that the coloration of the polymer was conspicuous, and the polymer became a gel depending on the reaction conditions, making it difficult to withstand use.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its purpose is not only to have good antibacterial properties, but also to reduce the degree of coloring of the polymer and gel. An object of the present invention is to provide a copolyester resin which can be suitably used as a molding material such as antibacterial fiber or antibacterial film by suppressing the degree of generation and increasing heat resistance.

[0006]

The copolymerized polyester resin of the present invention which has been able to solve the above-mentioned problems is a copolymerized polyester in which a part of the dicarboxylic acid component has a phosphonium salt of sulfonic acid as a substituent. , And M
In a copolyester resin containing at least one metal selected from the group consisting of g, Ca, and Mn, phosphoric acid and / or its derivative is contained in a total amount of 20 to 200 ppm in terms of P, and The gist is that the ratio of the total number of moles of P to the total number of moles of the metal is in the range of 0.4 to 1.0.

[0007]

The polyester resin of the present invention comprises a dicarboxylic acid component and a glycol component as main components, part of the dicarboxylic acid component has a phosphonium salt of sulfonic acid as a substituent, and is selected from the group consisting of Mg, Ca and Mn. The precondition is that the resin contains at least one selected metal. Then, by containing a specific amount of phosphoric acid and / or a derivative thereof in this resin and containing the above metal and phosphorus in a molar ratio within a specific range, the antibacterial activity is enhanced and the formation of coloring is suppressed, and the heat resistance is improved. It is characterized in that characteristics as a resin for molding materials are improved by enhancing molding processability such as strength and strength.

First, the basic skeleton of the resin of the present invention will be described. The polyester resin of the present invention is obtained by reacting a dicarboxylic acid component and a glycol component.

Examples of the dicarboxylic acid component include aromatic dicarboxylic acids, alicyclic dicarboxylic acids, aliphatic dicarboxylic acids, and heterocyclic dicarboxylic acids. Among these, aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid,
4,4-dicarboxyl phenyl, 4,4-dicarboxyl benzophenone, bis (4-carboxylphenyl) ethane and derivatives thereof, and the like, and alicyclic dicarboxylic acids include cyclohexane-1,4-dicarboxylic acid and its derivatives. Derivatives and the like, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, dodecanedioic acid, eicoic acid, dimer acid and their derivatives, and the like, as the heterocyclic dicarboxylic acid pyridinecarboxylic acid and its derivatives, etc. Is mentioned. In addition to such a dicarboxylic acid component, it is also possible to include oxycarboxylic acids such as p-oxybenzoic acid, and polyfunctional acids such as trimellitic acid, pyromellitic acid and derivatives thereof.

Examples of the glycol component include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, and an ethylene oxide adduct of bisphenol A. , Polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like. In addition, a small amount of a compound containing an amide bond, a urethane bond, an ether bond, a carbonate bond or the like may be contained.

In the polyester resin of the present invention, a phosphonium salt of sulfonic acid as a substituent is copolymerized with a part of the dicarboxylic acid component as an antibacterial component. Examples of such a phosphonium salt of sulfonic acid include a compound containing a phosphonium salt of sulfonic acid as a substituent in a part of an aromatic dicarboxylic acid, and specifically, tri-n-butyl sulfoisophthalate. Decylphosphonium salt, sulfoisophthalic acid tri-n-butyl octadecylphosphonium salt, sulfoisophthalic acid tri-n-
Butylhexadecylphosphonium salt, sulfoisophthalic acid tri-n-butyltetradecylphosphonium salt, sulfoisophthalic acid tri-n-butyldodecylphosphonium salt, sulfoterephthalic acid tri-n-butyldecylphosphonium salt, sulfoterephthalic acid tri-n- Butyl octadecyl phosphonium salt, sulfoterephthalic acid tri-n-
Butyl hexadecyl phosphonium salt, sulfoterephthalic acid tri-n-butyl tetradecyl phosphonium salt, sulfoterephthalic acid tri-n-butyl dodecyl phosphonium salt, 4-sulfonaphthalene-2,7-dicarboxylic acid tri-n-butyl decyl phosphonium salt , 4-sulfonaphthalene-2,7-dicarboxylic acid tri-n-butyloctadecylphosphonium salt, 4-sulfonaphthalene-2,7-
Dicarboxylic acid tri-n-butylhexadecylphosphonium salt, 4-sulfonaphthalene-2,7-dicarboxylic acid tri-n-butyltetradecylphosphonium salt, 4-sulfonaphthalene-2,7-dicarboxylic acid tri-n-butyldodecyl Examples thereof include phosphonium salts.

In the above phosphonium salt, the degree of antibacterial activity is strongly influenced by the length of the alkyl group (which may be the same or different) bonded to phosphorus, and for example, the alkyl group having 10 to 20 carbon atoms is at least The compound having one has a remarkably high antibacterial activity, and exhibits a remarkable antibacterial action as compared with the conventionally used quaternary ammonium salt. From this point of view, particularly preferable are sulfoisophthalic acid tri-n-butylhexadecylphosphonium salt, sulfoisophthalic acid tri-n-butyltetradecylphosphonium salt, and sulfoisophthalic acid tri-n-butyldodecylphosphonium salt. .

The phosphonium salt of sulfonic acid is, for example, a sulfonate of aromatic dicarboxylic acid (for example, dimethyl sodium 5-sulfoisophthalate, sodium sulfoterephthalate, etc.) and a phosphonium salt (for example, tri-n-).
Butylhexadecylphosphonium bromide, tri-n
-Butyltetradecylphosphonium bromide, tri-
n-butyl dodecylphosphonium bromide). The reaction solvent used in this reaction is not particularly limited, but water is most preferable.

In the present invention, the phosphonium salt of sulfonic acid is contained in the copolymer polyester resin in an amount of 1 to 20 mol%.
It is necessary to contain it in the range of. This is an amount necessary to effectively exhibit the antibacterial action and impart a predetermined viscosity to enhance moldability.

Such a copolyester resin further contains at least one metal selected from the group consisting of Mg, Ca and Mn. These metals are supplied to the polymerization reaction system in the form of salts such as magnesium chloride, magnesium acetate, calcium chloride, calcium acetate, manganese chloride and manganese acetate. These metals are useful for improving the degree of coloring and gel generation of the resin, and in order to effectively exhibit such an effect, the total amount of the metal is 20 to 300.
It is necessary to contain it in the range of ppm. If the content is within such a range, the above-mentioned metals may be contained alone or in combination of two or more kinds. Here, when the metal content exceeds 300 ppm, coloring of the polymer becomes remarkable, while when it is less than 20 ppm, improvement in heat resistance and antibacterial property cannot be obtained.

The above is a description of the polyester resin forming the skeleton of the present invention. In the present invention, such a polyester resin is further converted into P amount of (a) phosphoric acid and / or its derivative. 20 to 200 ppm in total, and (b) the ratio of the total number of moles of P to the total number of moles of the metal is in the range of 0.4 to 1.0.

Of these, phosphoric acid and / or its derivative is added for the purpose of improving the degree of coloring and the degree of gel formation of the copolyester of the present invention, as is the case with metals such as Mg. Examples of the phosphoric acid derivative include phosphoric acid trimethyl ester, phosphoric acid triethyl ester, phosphoric acid tripropyl ester, phosphoric acid tributyl ester, and the like. Of these, phosphoric acid and phosphoric acid trimethyl ester are preferably used from the viewpoint of improving the heat resistance and antibacterial property of the polymer.

In order to exert the action of these metals and phosphorus derivatives more effectively, it is necessary to set the ratio of the total number of moles of P to the total number of moles of the above metal to 0.4 to 1.0. is there.

When the above molar ratio is less than 0.4 or more than 1.0, coloring of the polymer is conspicuous, and coarse particles are remarkably formed, making it difficult to process into a molded product such as a fiber, film or plastic. Become. The preferred lower limit is 0.4
5, more preferably 0.50, while the preferable upper limit value is 0.95, more preferably 0.90.

Although the copolyester resin of the present invention has been described in detail as described above, it may further contain the following additives. For example, titanium dioxide, calcium carbonate, barium sulfate, calcium fluoride, talc, kaolin, silicon oxide, alumina, zirconium oxide, iron oxide, alumina /
Inorganic particles such as silica composite oxide; crosslinked polystyrene,
Examples thereof include organic particles such as crosslinked polymethacrylic acid ester and crosslinked polyacrylic acid ester.

Of these, some typical additives will be described. The calcium carbonate particles are classified into trigonal or hexagonal calcite according to their crystal structure; orthorhombic aragonite; and hexagonal or pseudohexagonal vaterite. It is classified into two crystal types. In the present invention, any of these crystal types can be used, and the shape thereof can be arbitrarily selected from a continuous spherical shape, a cubic shape, a spindle shape, a columnar shape, a needle shape, a spherical shape, an oval shape and the like.

The kaolin particles may be natural kaolin, synthetic kaolin, or any type regardless of whether they are calcinable or non-sinterable, and their shapes are plate-like, columnar, spherical, spindle-like, and egg-like. Etc. can be arbitrarily selected.

As the above-mentioned alumina, crystalline alumina hydrates such as gibbsite, bayerite, nordstrandite, boehmite, diaspore, and todite; amorphous alumina hydrates such as amorphous gel, boehmite gel, bayerite and the like; Examples include intermediate activated alumina such as ρ, η, γ, χ, κ, δ, and θ type or α type alumina.

The average particle size of these additives is not particularly limited, but the average primary particle system is preferably 0.01 μ or more and 5 μ or less, and the total addition amount is preferably 0.01 to 5% by weight. When the content of particles exceeds 5% by weight,
Coarse particles are remarkably generated in the copolyester resin,
When formed into a film, a fiber or the like, coarse projections are conspicuous on the surface of the formed product, which causes a problem that the quality, wear resistance and the like of the formed product are deteriorated.

No particular limitation is imposed on the production of the polyester resin of the present invention, and any method may be employed. For example, when the aromatic dicarboxylic acid and the glycol are reacted, a direct polymerization method of directly reacting them and a transesterification method of transesterifying the dimethyl ester of the aromatic dicarboxylic acid and glycol are applied. When the metal, phosphoric acid and its derivative are further added to the polyester resin thus obtained, it is recommended to add the phosphoric acid at the time of charging the raw material and before the polymerization reaction.

The copolyester resin of the present invention is used for packaging films, magnetic tape films, industrial films,
It is useful as a raw material for plastics, fibers, binders, etc. and is applied to various molded products. The film may be an unstretched film, a uniaxially oriented film, a biaxially oriented film, or the like, but a biaxially oriented film is particularly recommended from the viewpoint of film strength.

The present invention will be described in more detail with reference to the following examples, but the following examples are not intended to limit the present invention, and any modification or implementation is within the scope of the present invention without departing from the gist of the preceding and the following. It is included in the technical scope of.

[0028]

EXAMPLES The methods for measuring the physical properties of the copolyester resins obtained in the examples and comparative examples are shown below. Evaluation of Coloration of Polymer A polymer melt obtained by the polymerization reaction was put into liquid nitrogen and solidified. The color of this polymer was visually observed and evaluated according to the following criteria. ◯: It is transparent without coloring. Δ: Transparent, but colored slightly yellow. X: Transparent, but colored deep yellow.

Evaluation of Gelation Amount After completion of polycondensation, the produced polymer was extruded through an appropriate die to obtain a film having a thickness of 150 μm. This film was placed on an overhead projector and magnified and projected about 10 times. At this time, a scale for size measurement was also projected. Visually check the size of the film 0.8m
The number was counted in four stages of m or more, 0.5 mm or more and less than 0.8 mm, 0.2 mm or more and less than 0.5 mm, and 0.2 mm or less. The number measured in this way is 1 g of film
It was converted into per unit (unit: number / g). Next, according to the following criteria, the weighting correction of the number was performed for each stage. 0.8 mm or more ... x100 0.5 mm or more and less than 0.8 mm ... x50 0.2 mm or more and less than 0.5 mm ... x5 0.2 mm or less ... x0

After making the above correction, the average value was calculated, and the gelled product was evaluated according to the following ranking. ○: less than 10 points △: 10 points or more and less than 50 points ×: 50 points or more

Antibacterial Test Film pre-sterilized by high-pressure steam (5 cm × 6 c
m), 0.1 ml of S. aureus (1.0 Staphylococcus aureus) diluted with 1/50 broth (10 ⁷ cells / ml) was dripped onto the film, and a high pressure steam sterilized Saran wrap film was placed on the film. I made them stick. This test piece was transferred to a sterile petri dish and cultured at 37 ° C. for 24 hours. Next, the bacteria on the film were mixed with SCDLP medium (Soybean-Casein Diges
t Broth with Lecithin & Polysorbate 80) was washed with 10 ml, diluted 10 times and then spread on a regular agar plate, and after 24 hours, the number of bacteria was counted.

Example 1 149 g of terephthalic acid (TPA), 66 g of tri-n-butylhexadecylphosphonium salt of dimethyl 5-sulfoisophthalic acid (PC16), 124 g of ethylene glycol (EG), theoretical amount of copolymerized polyester Antimony trioxide (added as a polycondensation catalyst) was added as Sb amount of 250 ppm, magnesium acetate as Mg amount of 100 ppm, and phosphoric acid trimethyl ester was added.
The esterification reaction was carried out at 0 ° C. and a pressure of 2.5 kg / cm ² .

After the completion of the esterification reaction, 70 ppm of trimethyl phosphate as a P amount was added to the obtained reaction product, and the mixture was stirred at 260 ° C. for 10 minutes under normal pressure. After that, polycondensation reaction was performed for 30 minutes under vacuum, and the intrinsic viscosity was η = 0.6.
0 copolymerized polyester resin was obtained. The physical properties of the polyester resin thus obtained are shown in Table 1 below.

An average particle size of 0.
After mixing 10 parts by weight of polyethylene terephthalate in which 5 μm calcium carbonate fine particles are dispersed at a concentration of 20000 ppm, melt-extruding at 290 ° C. and cooling with a cooling roll at 30 ° C. to obtain an unstretched film having a thickness of about 180 μm. It was This unstretched film was stretched 3.5 times in the longitudinal direction between a pair of rolls heated to 85 ° C. and having different peripheral speeds, and then stretched 3.5 times in the transverse direction at 130 ° C. by a tenter, and further 200 times. A biaxially stretched copolyester film having a thickness of 14.5 μm was obtained by heat setting at ˜210 ° C. The antibacterial evaluation results of the obtained film are also shown in Table 1 below.

Examples 2 to 8 The kinds and amounts of the glycol compound, the phosphonium salt of sulfoisophthalic acid, and the kinds of the metal compound and the phosphorus compound contained in the polyester resin were changed as shown in Tables 1 and 2. Except for the above, the copolymer polyester resins of Examples 2 to 8 were obtained in the same manner as in Example 1. The physical properties of the resins thus obtained were evaluated in the same manner as in Example 1. In the table, NPG is neopentyl glycol, PC12 is 5-sulfoisophthalic acid dimethyl ester tri-n-butyldodecylphosphonium salt, and PC14 is 5-sulfoisophthalic acid dimethyl ester tri-n-butyltetraester. Represents a decylphosphonium salt, respectively.

Comparative Examples 1 to 9 The kinds and amounts of glycol compounds, phosphonium salts of sulfoisophthalic acid, and kinds of metal compounds and phosphorus compounds contained in the polyester resin were changed as shown in Tables 1 and 2. Except for the above, a polyester resin was produced in the same manner as in Example 1, and the physical properties thereof were evaluated in the same manner. The measurement results in the above Examples and Comparative Examples are summarized in Tables 1 and 2.

[0037]

[Table 1]

[0038]

[Table 2]

As is clear from these results, the polyester resin of the present invention is excellent in antibacterial properties, and is resistant to coloring and gelation and is excellent in thermal stability. It has been found to be very useful as a material. On the other hand, the resin of Comparative Example which did not satisfy the requirements of the present invention was inferior to any of the above properties.

[0040]

Since the copolyester of the present invention is constituted as described above, it has good antibacterial properties, and is less likely to cause coloring and gelation and has excellent thermal stability.
It can be suitably used as a molding material such as antibacterial fiber or film.

Claims (1)

[Claims] 1. A copolymerized polyester in which a part of the dicarboxylic acid component has a phosphonium salt of sulfonic acid as a substituent, and contains at least one metal selected from the group consisting of Mg, Ca and Mn. The copolymerized polyester resin contains phosphoric acid and / or its derivative in a total amount of 20 to 200 ppm in terms of P amount, and the ratio of the total mole number of P to the total mole number of the metal is 0.4 to 1 A copolymerized polyester resin having excellent antibacterial properties, which is in the range of 0.0.