JPH0860036A - Antibacterial antifungal polyester resin composition for powder coating - Google Patents

Abstract

PURPOSE: To obtain an antibacterial antifungal polyester resin composition for powder coating which can be produced at a relatively low cost by using zeolite solid particles carrying ions of a specified metal. CONSTITUTION: This composition is prepared by mixing a polyester for a powder coating material having an intrinsic viscosity of 0.15-0.40dl/g with 0.01-10wt.% zeolite solid particles carrying ions of a metal selected from among silver, copperl and zinc. It is desirable that the polyester resin has a softening point of 50-150 deg.C. When it is one terminated mainly with a hydroxyl group, it has desirably a hydroxyl value of 230-1500geq/10<6> g, while, when it is one terminated mainly with a carboxyl group, it has desirably an acid value of 230-1500geq/10<6> g. The zeolite may be natural one or synthetic one. It is desirable that the zeolite is in the form of a fine powder having a particle diameter of desirably 5μm or below. This composition is mixed with a curing agent to obtain a powder coating material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition for powder coating which has excellent antibacterial and antifungal properties.

[0002]

2. Description of the Related Art Recently, in homes, hospitals and factories, especially in chemicals and food factories, problems such as mold growth on the coating surface have been raised, and solvent-based paints containing antibacterial and antifungal agents have appeared. . However, in recent years, environmental pollution due to organic solvents has become a serious problem, and water-based paints and high solid paints have come to be used. Therefore, although a paint prepared by adding an antibacterial and antifungal agent to a water-based paint has been proposed,
These water-based paints and high-solid paints require organic solvents, albeit in small amounts, and are not preferable in terms of environmental pollution.

On the other hand, powder coating materials are non-polluting coating materials, can be used immediately after coating, do not require multi-layer coating, and are relatively inexpensive as compared with conventional solvent type coating materials. There are advantages such as being able to recover and use the surplus at the time of painting, building materials, home appliances,
Demand is rapidly expanding in recent years as a paint for protection and decoration of parts such as automobile parts.

In the field of powder coatings, a resin composition for antibacterial powder coatings comprising a specific zirconium phosphate salt and a resin for powder coatings is known as a coating having antibacterial and antifungal properties (special characteristics). Kaihei 6-25561) has not known a powder coating having antibacterial properties using zeolite solid particles carrying a metal exhibiting antibacterial properties.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a polyester resin composition for powder coating having antibacterial and antifungal properties which can be produced at a relatively low cost.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the inventors of the present invention blended zeolite solid particles carrying a specific metal ion into a polyester resin for powder coating. As a result, they have found that a polyester resin composition for powder coating having antibacterial and antifungal properties can be obtained, and completed the present invention.

That is, the present invention has an intrinsic viscosity of 0.15 to 0.
An antibacterial and antifungal powder characterized by containing 0.01 to 10% by weight of zeolite solid particles supporting a metal ion selected from silver, copper and zinc in a polyester resin for powder coating of 40 dl / g The subject is a polyester resin composition for body paint.

The present invention will be described in detail below.

In the present invention, the polyester resin for powder coating must have an intrinsic viscosity of 0.15 to 0.40 dl / g. If the intrinsic viscosity is less than 0.15 dl / g, the blocking resistance of the composition will be poor, while if it exceeds 0.40 dl / g, the pulverizability will be poor. Particularly preferred are those having an intrinsic viscosity of 0.20 to 0.35 dl / g.

Furthermore, since it is for powder coatings, it has a softening point of 50.
It is preferably in the range of to 150 ° C.

If the softening point is less than 50 ° C., the powdered resin tends to agglomerate and solidify, resulting in poor blocking resistance. On the other hand, if the softening point exceeds 150 ° C, the kneading temperature must be raised, and the reaction with the curing agent has already progressed during melt kneading, resulting in a decrease in the smoothness and mechanical strength of the coating film. is there.

The polyester resin for powder coating includes a polyester resin having a hydroxyl group as a main terminal and a polyester resin having a carboxyl group as a main terminal, and any type can be used in the present invention.

In the case of a polyester resin having hydroxyl groups at the main terminals, those having a hydroxyl value of 230 to 1500 geq / 10 ⁶ g are preferable. If the hydroxyl value is less than 230 geq / 10 ⁶ , large unevenness will occur on the surface of the coating film, and the smoothness will decrease. On the other hand, if the hydroxyl value exceeds 1500 geq / 10 ⁶ g, not only the mechanical strength of the coating film will decrease, but if the curing agent is added so that the functional group amount corresponds to the hydroxyl value of the resin, the coating will be expensive. Will be.

In the case of a polyester resin having a carboxyl group as a main terminal, an acid value of 230 to 1500 geq / 10 ⁶ g is preferable. If the acid value is less than 230 geq / 10 ⁶ g, large unevenness is generated on the surface of the coating film, resulting in poor smoothness. On the other hand, the acid value is 15
If it exceeds 00geq / 10 ⁶ g, the mechanical strength of the coating film decreases.

Examples of the acid component of the polyester resin include dicarboxylic acids, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and phthalic anhydride, and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid and dodecanedioic acid. Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid are mainly used. A tricarboxylic or higher carboxylic acid such as trimellitic acid, pyromellitic acid or trimesic acid may be used in combination with the dicarboxylic acid as long as the polyester resin is not gelled.

As the alcohol component, glycols such as ethylene glycol, neopentyl glycol,
Diethylene glycol, propylene glycol, 1,4-
Butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, and an adduct of bisphenol A with ethylene oxide are mainly used. A trifunctional or higher functional polyol such as trimethylolpropane, glycerin, and pentaerythritol may be used together with the glycol in a range that does not cause the polyester to gel.

A small amount of hydroxycarboxylic acid such as 4-hydroxybenzoic acid or ε-caprolactone may be used in combination.

The polyester resin in the present invention can be prepared by a conventional method for polyester production, using the above-mentioned components (including their ester-forming derivatives) as raw materials.

In the present invention, the solid zeolite particles carrying metal ions are mixed with the polyester resin for powder coating as described above. Since powder coating materials are mixed with a curing agent and various additives in the manufacturing process and melt-kneaded, the antibacterial and antifungal agents used must have some heat resistance and the reaction between the polyester resin and the curing agent. Must have no effect on. The zeolite solid particles carrying metal ions used in the present invention meet this condition.

In the zeolite solid particles carrying the metal ions used in the present invention, the metal ions are preferably carried by ion exchange. In the case of simply adsorbing or adhering a metal compound without using ion exchange,
There may be a problem with the bactericidal effect and its sustainability.
As the metal ion, one or more of sterilizing silver, copper and zinc is used.

In the present invention, the solid zeolite particles carrying metal ions selected from silver, copper and zinc are aluminosilicates. Many types of zeolites are known, which differ in composition ratio, pore size, specific surface area, and the like. However, the zeolite solid particles used in the present invention have a specific surface area of 150 m ² / g (anhydrous zeolite reference) or more, and the SiO ₂ / Al ₂ O ₃ molar ratio of the zeolite constituents is 14 or less, particularly 11 or less. Those are preferable. SiO ₂ / Al ₂ O ₃ molar ratio is
With a zeolite of 14 or less, it is possible to uniformly carry metal ions having a bactericidal action, and by using such a zeolite, a sufficient bactericidal effect can be obtained.

As the zeolite material used in the present invention, both natural and synthetic zeolites can be used.

As natural zeolite, anarsine is used.
_{(Analcime: SiO 2 / Al 2} O 3 = 3.6~5.6), chabazite (Chab
_{azite: SiO 2 / Al 2 O} 3 = 3.2~6.0 and 6.4 to 7.6), clinoptilolite _{(Clinoptilolite: SiO 2 / Al 2} O 3 = 8.5~10.
5), Erionite (SiO ₂ / Al ₂ O ₃ = 5.8 to 7.
4), Faujasite (SiO ₂ / Al ₂ O ₃ = 4.2 ~ 4.
6), mordenite _{(Mordenite: SiO 2 / Al 2} O 3 = 8.34~10.
0), Phillipsite (SiO ₂ / Al ₂ O ₃ = 2.6
~ 4.4) and the like.

As the synthetic zeolite, A-type zeolite (SiO ₂ / Al ₂ O ₃ = 1.4 to 2.4), X-type zeolite (SiO ₂ / A
l ₂ O ₃ = 2 to 3), Y-type zeolite (SiO ₂ / Al ₂ O ₃ = 3 to 6), mordenite (SiO ₂ / Al ₂ O ₃ = 9 to 10) and the like.

Particularly preferred are mordenite and chabazite for natural zeolites and A for synthetic zeolites.
-Type zeolite, X-type zeolite, Y-type zeolite and mordenite.

The shape of the zeolite is preferably in the form of fine powder, and the particle diameter may be appropriately selected according to need, but is preferably 5 μm or less, particularly 2 μm or less.

In the resin composition of the present invention, the proportion of solid antibacterial zeolite particles in the composition must be 0.01 to 10% by weight (as anhydrous zeolite).
If the amount of the antibacterial zeolite solid particles is less than 0.01% by weight, it is unsatisfactory in terms of bactericidal effect, and if it exceeds 10% by weight, for example, even if it is 50% by weight, the bactericidal effect is almost unchanged.
When used as a paint, its mechanical properties are poor.

The solid zeolite particles carrying metal ions can be added to the polyester resin for powder coating at any stage during the synthesis of the polyester resin for powder coating or during coating.

When the resin composition of the present invention is used as a powder coating, it is necessary to add a curing agent.

When a polyester resin having a hydroxyl group as a main terminal is used, an isocyanate type curing agent, a glycoluril type curing agent or the like is used. As the isocyanate-based curing agent, B1530, B1065, BF154 manufactured by Huls
0 and the like. Examples of the glycoluril-based curing agent include tetramethoxymethylglycoluril curing agent, such as POWDERLINK 1174 manufactured by Cytec. The amount of the curing agent used is appropriately in the range of 0.8 to 1.2 times equivalent amount of functional groups, which corresponds approximately to the amount of hydroxyl groups of the polyester resin.

When a polyester resin having a carboxyl group as the main terminal is used, an epi-bis type epoxy resin derived from bisphenol A and epichlorohydrin, a melamine type curing agent, triglycidyl isocyanurate, etc. are used. As the epi-bis type epoxy resin, Tohto Kasei Co., Ltd.YD-128, YD-014, etc., as the melamine-based curing agent, Rohm & Haas Co., Ltd. Primid XL-552, etc., and as triglycidyl isocyanurate, Ciba Geigy Co. 810 etc. are mentioned. The amount of curing agent used is
It is suitable that the amount of the functional group substantially corresponds to the acid value of the polyester resin, preferably 0.8 to 1.2 times the equivalent.

If necessary, a leveling agent, a curing catalyst, a pigment such as titanium dioxide or carbon black, and other additives may be added.

[0033]

[Function] The reason why the polyester resin composition for powder coating of the present invention has excellent antibacterial and antifungal properties is that zeolite, silver,
It is presumed that the metal ion selected from copper and zinc is held by an ionic bond, so that it is safe and its effect lasts. In addition, since zeolite is also excellent in heat resistance, it is possible to obtain an antibacterial and antifungal polyester resin composition for powder coating at a relatively low cost without problems in the powder coating manufacturing process and heat during baking. It is presumed that.

[0034]

EXAMPLES Next, the present invention will be explained by examples. The measuring method of the characteristic value is as follows. (a) Intrinsic viscosity It was determined from the solution viscosity measured at 20 ° C using an equal weight mixture of phenol and ethane tetrachloride as a solvent. (b) Hydroxyl value After acetylation, it was determined by titration with a methanol solution of potassium hydroxide. (c) Acid value It was determined by dissolving in dioxane and titrating with a potassium hydroxide methanol solution. (d) 60 degree specular gloss Measured according to JIS K 5400. (e) Impact resistance: Measured according to JIS K 5400 using a ball having a diameter of 1/2 inch and 1 kg. (f) Antibacterial property A coating composition is coated on a zinc phosphate-treated steel sheet having a diameter of 30 mm so that the coating film becomes uniform, and baked at 190 ° C for 20 minutes to obtain a test piece. Next, test the test piece with 1 liter of water and glucose.
Attach to the center of the culture surface of a plate medium consisting of g, 10 g of peptone, and 10 g of agar. Furthermore Aspergillus nige
r, Penicillium funiculosum, Cladosporium cladospr
1 ml of a mixed spore suspension of ioides and Aureobasidium Pullulans is evenly spread on the surface of the medium and on the test piece, and the Petri dish is covered and incubated at 28 ° C for 14 days. And, ++ when the bacteria did not grow, 1/3 of the test piece
The case where the bacteria grow is shown as +, and the case where the bacteria grow to about 1/3 or more is shown as − below.

The antibacterial agents A to D used in the examples are shown below.

A: Natural mordenite supporting silver ion B: Natural mordenite supporting copper ion C: Natural chabazite supporting silver ion D: Synthetic A-type zeolite supporting silver ion Examples 1 to 4 and Comparative Examples 1-3 The raw material compounds shown in Table 1 were placed in an esterification reaction vessel in the amounts (parts by weight) shown in Table 1 and subjected to a pressure of 2.5 kg / cm ² and 160
An esterification reaction was carried out at ˜250 ° C. for 4 hours, and water produced was removed from the reaction system to prepare an esterified product. After transferring the obtained esterified product to a polycondensation reactor, 5.83 g of antimony trioxide (2 × 10 ⁻⁴ mol / mol of acid component) as a catalyst,
3.65 g of triethyl phosphate (2 × 10 ^-4 mol / mol of acid component) and 0.68 g of tetrabutyl titanate (0.2 × 10 ^-4 mol / mol of acid component) were added, and polycondensed at 280 ° C. for 3 hours under a reduced pressure of 0.4 hPa. The reaction was carried out to obtain a polyester having an intrinsic viscosity of 0.45 dl / g. Next, the compounds listed in the column of depolymerization in Table 1 were added to this polyester in the amounts (parts by weight) shown in Table 1, and the depolymerization reaction was carried out at 270 ° C. for 1 hour under normal pressure in an inert atmosphere, A polyester resin having the characteristic values shown in Table 1 was obtained. In the obtained polyester resin, a blocked isocyanate curing agent; B 1530 manufactured by Hüls Ltd. is used as a functional group amount corresponding to the hydroxyl value of the polyester resin, and the total amount of the resin and the curing agent is 100 parts by weight. The amount of antibacterial agents shown (parts by weight) in Table 1, dioctyltin maleate
(Curing catalyst): 0.3 parts by weight of Stann OMF manufactured by Sansha Kisei Co., Ltd., butyl polyacrylate-based leveling agent: 1 part by weight of Acronal 4F manufactured by BASF, 0.5 part by weight of benzoin,
Titanium dioxide pigment; rutile titanium dioxide manufactured by Ishihara Sangyo Kaisha, Ltd.
After adding CR-90 in a ratio of 50 parts by weight and dry blending with FM 10B type Henschel mixer (Mitsui Miike Seisakusho),
A PR-46 type co-kneader (manufactured by Buss) was melt-kneaded at 110 ° C., cooled, pulverized, and separated with a 140-mesh wire net to obtain a powder coating material.

The powder coating thus obtained was electrostatically coated on a zinc phosphate-treated steel sheet and baked on at 180 ° C. for 20 minutes. The test piece was coated with 60 ° specular gloss, impact resistance and antibacterial property. The sex was evaluated. Table 1 shows the evaluation results of coating film performance.

[0038]

[Table 1]

Comparative Example 4 An attempt was made to prepare a powder coating material in the same manner as in Example 1, using a polyester resin having an intrinsic viscosity of 0.45 dl / g before the depolymerization reaction in Example 1. It was difficult to pulverize the polyester resin, and it was not possible to obtain a powder coating material that could be used for the test.

Examples 5 to 7 Polyesters having an intrinsic viscosity of 0.45 dl / g were obtained in the same manner as in Example 1 except that the raw material compounds shown in Table 2 were used in the amounts (parts by weight) shown in Table 2. Then, the amount of the compound described in the column of depolymerization of Table 2 in this polyester (part by weight)
And the antibacterial agents shown in Table 2 were added in the amounts (parts by weight) shown in Table 2 and the depolymerization reaction was carried out at 270 ° C. for 1 hour under atmospheric pressure in an inert atmosphere to obtain the characteristic values shown in Table 2. A polyester resin was obtained. The same amount of the composition excluding the antibacterial agent was added to the obtained polyester resin, and a powder coating material was obtained in the same manner as in Example 1. Using the obtained powder coating material, Example 1
Table 2 shows the results of evaluation of coating film performance by obtaining test pieces in the same manner as in.

[0041]

[Table 2]

Examples 8 to 11 and Comparative Examples 5 to 6 In the same manner as in Example 1, except that the starting compounds shown in Table 3 were used in the amounts (parts by weight) shown in Table 3, the intrinsic viscosity was 0.45 dl / g. I got polyester. Then, the amount of the compound described in the column of depolymerization in Table 3 in this polyester (part by weight)
Then, the depolymerization reaction was carried out at 250 ° C. for 3 hours under atmospheric pressure in an inert atmosphere to obtain a polyester resin having the characteristic values shown in Table 3. To the obtained polyester resin, the same composition as in Example 1 was added in the same amount as in Example 1 except that the curing agent and the curing catalyst were changed as follows. Obtained. Using the obtained powder coating material, Example 1
Table 3 shows the results of evaluation of coating film performance by obtaining test pieces in the same manner as in. Curing agent: Epi-bis type epoxy resin; Toto Kasei YD-128 (Examples 8 to 9 and Comparative Example 5) Toto Kasei YD-128 (Examples 10 to 11 and Comparative Example 6) Curing catalyst: 2 -Undecyl imidazole; Cuizol C11Z 0.2 parts by weight manufactured by Shikoku Kasei

[0043]

[Table 3]

[0044]

According to the present invention, a polyester resin composition for a powder coating having antibacterial and antifungal properties is provided at a relatively low cost.

Claims (1)

[Claims] 1. Zeolite solid particles in which a polyester resin for powder coating having an intrinsic viscosity of 0.15 to 0.40 dl / g is loaded with a metal ion selected from silver, copper and zinc in an amount of 0.01 to 10
A polyester resin composition for antibacterial and antifungal powder coatings, characterized in that it is contained by weight%.