JPS6219306B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polymer laminate sheet,
More specifically, the present invention relates to a polymeric laminated sheet containing an active substance having physical and/or chemical activity and capable of releasing the active substance in a sustained manner.

As shown in FIG. 1, an active substance storage layer 1 made of a polymer containing a refractory or volatile active substance having physical and/or chemical activities such as pesticide activity, repellent activity, and aromatic activity. Control layer 2 consisting of a polymer for controlling the release of this active substance on the surface
It has a barrier layer 3 having barrier properties against active substances such as polypropylene, polyamide, polyethylene terephthalate, etc. on the back side, and further has an adhesive layer 4 on the exposed surface of the barrier layer, and has a desired adhesive layer. Various functional polymer laminate sheets are known that are adhered to a surface to allow sustained release of an active substance from the surface of a control layer or to transfer an effective concentration of an active substance to the surface of a control layer.

However, especially when the active substance is volatile, none of the polymers conventionally used as control layers are able to control the sustained release of the active substance satisfactorily, and the sustained release function is not sustained over a long period of time. In addition, in order to prolong the sustained release function,
It has also been attempted to include an excess of active substance in the storage polymer layer, but this method is uneconomical and reduces the amount of active substance released, especially at the initial stage, because it unnecessarily exceeds the effective level. Some types of substances can even be harmful.

Conventionally, such a polymeric laminate sheet is manufactured by adhering a sheet-shaped active substance storage layer, a control layer, and a barrier layer, respectively, which requires multiple steps and is therefore expensive to manufacture. In addition, in order to form an active substance storage layer, the active substance is dispersed in plastisol and applied to a synthetic resin film, or a solution of the active substance is applied to a synthetic resin film and dried. , similarly requires multiple steps.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a method for producing a polymer laminate sheet that enables sustained release of active substances over a long period of time.

The method for producing a polymeric laminate sheet of the present invention includes combining a first polymer containing an active substance and a second polymer having barrier properties against the active substance; and a second polymer in the order of multilayer extrusion, thus providing sustained release of the active substance only from the sides of the first polymer layer not covered by the second polymer. It is characterized by

In the present invention, an active substance refers to a substance that has physical and/or chemical activity, and activities include chemical activity including pesticide activity such as insecticidal, sterilizing, antifungal, repellent, and attracting activity, and physical activity such as aroma. Examples include, but are not limited to, physical activities such as physical activity, chemical activity, electrical conductivity, and antistatic property.

Specific examples of active substances include 2,2-dichlorovinyl phosphate (DDVP), organophosphorus and pyrethroid insecticides such as Sumithion, fungicides such as P-chloro-m-xylenol, and diethyltoluamide (DET). ) etc., mosquito, tick, and cockroach repellents, pheromones, attractants such as methyleugenol, linemon, benzyl alcohol, carbon number 6~
Mention may be made of perfume substances such as esters, ethers and aldehydes derived from 16 hydrocarbons.

In the present invention, the first polymer containing the active substance is a synthetic resin, natural rubber, synthetic rubber, or any of these which can dissolve and contain the active substance at a concentration of 5% by weight or more, preferably 10% by weight or more at a temperature of 15°C. Various materials are used depending on the type of active substance, but specific examples include polyvinyl chloride, ethylene-vinyl acetate copolymer with a vinyl acetate content of 12% by weight or more, and acrylic acid with a content of 15% by weight. % by weight or more of ethylene-acrylic acid copolymer, styrene-butadiene rubber, ethylene-propylene rubber, styrene-isoprene-styrene block copolymer, natural rubber, thermoplastic urethane elastomer, and mixtures of two or more of these. I can do it. When the polymer is polyvinyl chloride, the polymer may contain a plasticizer such as dioctyl phthalate.

The content of the active substance in these polymers is appropriately determined depending on the type of active substance and polymer used, the purpose of the polymer laminate sheet, the conditions of use, etc., but in the case of agricultural chemicals, fragrances, etc. ~50% by weight, preferably 10-50% by weight. When the content of the active substance is too low, the activity expressed by the laminate is small and the duration of the activity is short, making it impractical for some applications, while on the other hand, when the content of the active substance is too high. This is because it becomes difficult to form into a sheet.

In the present invention, the second polymer used as the barrier layer is not particularly limited as long as it has barrier properties against the active substance, but typically includes ethylene-vinyl alcohol copolymer, polyethylene terephthalate, polyvinylidene chloride, polyamide, etc. used.

In the present invention, the above-described second polymer, the first polymer containing the active substance, and the second polymer are simultaneously multilayer extruded so that they are laminated in this order. Note that the two second polymers sandwiching the first polymer layer may be the same or different,
Selected appropriately. As is already known in multilayer extrusion molding, for example, each polymer is melt-kneaded in an extruder, fed into a single multilayer sheet die from separate inlets, and then each polymer is mixed at the confluence point in the die. It is fused into multiple layers and extruded from a die lip. Alternatively, immediately after each polymer is extruded into a sheet from a die, the sheets are laminated and pressed together.

FIG. 2 shows a polymer laminate sheet obtained by the method of the present invention, in which a first polymer layer 1 containing an active substance is coated with a barrier layer 3 consisting of a second polymer layer on both its front and back surfaces. Covered. The method of the present invention requires that the side surface area of the polymer layer be sufficiently small compared to the surface area and volume of the polymer layer.
As a result, according to the polymer laminated sheet obtained by the method of the present invention, the active substance is prohibited from being released from the surface and is released only from the side, so that the initial release rate is not unnecessarily increased and the active substance is released from the side. , it is possible to keep the release rate approximately constant over a long period of time, thus significantly increasing the duration of sustained release of the active substance at effective levels.

In addition, when the polymer laminated sheet is used by being attached to furniture, floors, walls, etc., an adhesive layer is provided on the surface of one of the barrier layers as necessary.

According to the method of the present invention, as described above, a polymer laminate sheet is produced by simultaneous multilayer extrusion molding of a first polymer containing a dissolved active substance and a second polymer as a barrier layer. Unlike the conventional method described above, the number of steps is significantly reduced and the manufacturing cost is also low.

Examples of the present invention are listed below, but the present invention is not limited to these Examples. In addition, in the following examples, parts indicate parts by weight.

Example Fragrance (Fragrance GARDENIA HH- manufactured by Takasago Fragrance Co., Ltd.)
2942) and 400 parts of ethylene-vinyl acetate copolymer resin (P3307 manufactured by Mitsui Polychemical Co., Ltd.) were kneaded with a hot roll, and then pressed to form an approximately 2 mm x 5 mm x 500
Cut into mm ribbons.

As a polymer formulation for the barrier layer, 100 parts of vinylidene chloride resin Saran 311 manufactured by Dow Chemical Company;
10 parts of an epoxy stabilizer and 3 parts of a tin stabilizer were mixed in a Henschel mixer.

The fragrance-containing compound and the Saran resin compound were simultaneously extruded using a three-layer T-die to form a three-layer sheet consisting of a Saran resin layer, a fragrance-containing polymer layer, and a Saran resin layer in this order.

A 20 mm diameter extruder was used for extrusion of Saran resin, and the extruder temperature was 160 °C, and 40 °C for extrusion of fragrance-containing polymers.
A mm diameter extruder was used, and the extruder temperature was 130°C. Also, the die temperature was 165°C. In the three-layer sheet thus obtained, each barrier layer is
100μ, and the fragrance-containing polymer layer was 900μ.

Cut this sheet into 10cm x 10cm and heat it at 40℃ or 50℃.
Weight loss due to fragrance release was measured in a constant temperature bath at 0.degree. The results are shown in Figure 3.

Comparative Example An ionomer resin (Himilan P1702 manufactured by Mitsui Polychemical Co., Ltd., ion type Zn, MI 14 g/10 min) was used as the polymer for the control layer, the same formulation as in the example, and acrylic acid content of 8% by weight as the adhesive.
EAA resin (EAA459 manufactured by Dow Chemical Company,
The above ionomer resin, compound and EAA resin were simultaneously multi-layer extruded in this order using a three-layer T-die using MI90g/10 minutes), and the ionomer resin layer, the aroma active substance-containing polymer layer and the EAA resin layer were sequentially formed.
It was made into a three-layer sheet consisting of a resin layer. A 20mm diameter extruder is used for extrusion of ionomer resin and EAA resin.
A 40 mm diameter extruder was used to extrude the aromatic active substance-containing polymer, and the extruder temperature was 130°C and the die temperature was 140°C. The EAA resin layer of the three-layer sheet obtained in this way
15μ aluminum foil is thermocompressed at a temperature of 12℃,
Control layer thickness 100μ, fragrance-containing polymer layer thickness 900μ,
A polymer laminated sheet with an adhesive layer thickness of 100 μm was obtained.
Cut this sheet into 10cm x 10cm and heat it at 40℃ or 50℃.
Weight loss due to fragrance release was measured in a constant temperature bath at 0.degree. The results are shown in Figure 3. Compared to the laminated sheet according to the present invention, the initial fragrance release is much greater and the sustained fragrance release period is significantly shorter. Further, in the case of the laminated sheet of the present invention, although the fragrance was observed even after 40 days, the laminated sheet of this comparative example had no fragrance after 25 days under the same conditions.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional polymer laminate sheet, Fig. 2 is a sectional view showing an example of the polymer laminate sheet of the present invention, and Fig. 3 is a sectional view of a polymer laminate sheet of the present invention and a comparative example. 1 is a graph showing the weight loss of active substance versus time; 1... Active substance-containing polymer layer, 3... Barrier layer.

Claims (1)

[Scope of Claims] 1. A first polymer containing an active substance and a second polymer having barrier properties against the active substance are combined into a second polymer, a first polymer and a second polymer having barrier properties against the active substance. A polymer characterized by multilayer extrusion molding in the order of two polymers, so that the active substance is released in a sustained manner only from the sides of the first polymer layer that are not covered by the second polymer. Method for manufacturing laminated sheets. 2. The method for producing a polymeric laminate sheet according to claim 1, wherein the active substance is a chemical substance having pesticide activity or aromatic activity. 3. The first polymer is polyvinyl chloride, an ethylene-vinyl acetate copolymer with a vinyl acetate content of 12% by weight or more, an ethylene-acrylic acid copolymer with an acrylic acid content of 15% by weight or more, styrene-butadiene rubber, 2. The method for producing a polymer laminate sheet according to claim 1, wherein the material is ethylene-propylene rubber, styrene-isoprene-styrene block copolymer, natural rubber, or a mixture of two or more thereof. 4. The polymer laminate according to claim 1, wherein the second polymer is an ethylene-vinyl alcohol copolymer, polyethylene terephthalate, polyvinylidene chloride, polyamide, or a mixture of two or more thereof. Method of manufacturing sheets.