JP7211590B2 - 3-layer colored film with a matte feel - Google Patents

Description

TECHNICAL FIELD The present invention relates to the technical field of packaging thin films, and specifically to a three-layer colored film with a matte feel.

Currently, the mainstream sanitary napkin products on the market are those printed on polyethylene (hereinafter sometimes abbreviated as PE) transparent film and opaque film, and sanitary napkin packaging bags are generally composite film products. , and PE milky film products. Among them, composite film products adopt the method of matting on the outer layer, printing on the intermediate layer, and overall printing on the inner surface PE. The PE opaque film product adopts the method of overall printing on single-layer and three-layer films.

The above products mainly have the following problems. That is, many transparent matte films are single-layered and are manufactured by adding an opening agent to 100% matte linear low-density polyethylene. When mixed with polyethylene or matte linear low-density polyethylene, the matte feeling is affected whether it is a single-layer film or a three-layer film.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a three-layer colored film having a matt feeling that is advantageous for environmental protection by reducing the printing area.

In order to solve the above problems, a three-layered colored film as one aspect of the present invention has a matte feel and is composed of an outer layer, an intermediate layer, and an inner layer, and the outer layer is composed of the following raw materials : consisting of 90-98% by mass of matte linear low-density polyethylene, 0-7% by mass of high-pressure low-density polyethylene or transparent low-density polyethylene, and 2-3% by mass of an opening agent; 70 to 90% by mass of erased linear low density polyethylene, 0 to 10% by mass of transparent linear low density polyethylene, 0 to 10% by mass of high pressure low density polyethylene, and 10 to 20% by mass of colored masterbatch the inner layer comprises the following raw materials: 35-60% by weight matte linear low-density polyethylene, 27-40% by weight transparent linear low-density polyethylene, 10-25% by weight high-pressure low-density polyethylene, and apertures 2.5 to 4% by mass of the agent.

The three-layer colored film may have a glossiness of 9.0 or less.

The colored masterbatch may be a light colored masterbatch containing an inorganic pigment, and the concentration of the inorganic pigment in the colored masterbatch may be 20% by mass or less.

The interlayer ratio of the outer layer, intermediate layer and inner layer may be outer layer:intermediate layer:inner layer=1.0-1.2:1.0-2.0:0.5-1.0. Further, as a method for producing the three-layer colored film, the resin composition constituting the outer layer, the resin composition constituting the intermediate layer, and the resin composition constituting the inner layer are co-extruded and inflation-molded. can be

According to the present invention, it is possible to obtain a three-layer colored film having a matte feel, which makes it possible to reduce the printing area.

Embodiments of the present invention will be described below. The present invention provides a three-layer colored film having a matte feel, the three-layer colored film is composed of an outer layer, an intermediate layer, and an inner layer, and the outer layer is composed of the following raw materials: matte linear low-density 90-98% by weight of polyethylene, 0-7% by weight of high-pressure low-density polyethylene or transparent low-density polyethylene, and 2-3% by weight of an opening agent; ~90% by weight, 0-10% by weight of transparent linear low density polyethylene, 0-10% by weight of high pressure low density polyethylene, and 10-20% by weight of a colored masterbatch; 35 to 60% by weight of matte linear low density polyethylene, 27 to 40% by weight of transparent linear low density polyethylene, 10 to 25% by weight of high pressure low density polyethylene, and 2.5 to 4% by weight of opening agent Manufactured from The colored masterbatch is an inorganic pale colored masterbatch, and the concentration of the inorganic pigment in the inorganic pale colored masterbatch is 20% by mass or less. The three-layer colored film is inflation-molded, and has a glossiness (in the present invention, glossiness defined in JIS K7105) of 9.0 or less. The interlayer ratio of the three layers is outer layer:intermediate layer:inner layer=1.0-1.2:1.0-2.0:0.5-1.0.

In the present embodiment, three-layer inflation molding is employed to form a colored matte film (glossiness of 9.0 or less), and by controlling the interlayer ratio of the three layers, the matte feeling is maximized. can be done. The light-colored masterbatch contains an inorganic pigment, and from the results calculated based on the interlayer ratio, the concentration of the inorganic pigment is 20% by mass or less, and the concentration of the inorganic pigment in the resin composition is 1.5% by mass. The following colored masterbatches are used and mixed before blow molding. Since linear low-density polyethylene has a high melting point, low-temperature heat-sealing performance was difficult.

Colored masterbatches are divided into organic color masterbatches and inorganic color masterbatches. Organic pigments include colors such as blue, green, yellow, pink, and purple. Organic pigments have strong adhesion to metals, so they adhere to extruder pumps and die heads. hard to do. Inorganic color masterbatches are usually milky white and have poor adhesion to metals, so they do not adhere to the pump and die head of an extruder, and are easily decolored when switching raw materials. Conventionally, organic color masterbatches are inferior in weather resistance, which has been a problem, but by using inorganic color masterbatches, it is possible to obtain three-layer colored films with excellent weather resistance. Therefore, a further feature of the present invention is that this three-layer colored film is produced using an inorganic colored masterbatch (with a concentration of 20% by mass or less).

There are two types of existing matte linear low-density polyethylene (FB2230, FB2310). When the outer layer, intermediate layer, and inner layer are all matte linear low-density polyethylene + colored masterbatch + opening agent, the glossiness is increases, causing a decrease in matte feeling. When the outer layer is 100% matte raw material and the intermediate layer is matte raw material + colored masterbatch, matte feeling (glossiness of 9.0 or less) is affected by the formulation of the inner layer raw material. Therefore, the present invention has been completed through intensive studies in order to secure a matte feeling (glossiness of 9.0 or less).

The melting point of matte linear low density polyethylene FB2230 is 124°C, the melting point of FB2310 is 127°C, the melting point of high pressure low density polyethylene is 112°C, and the melting point of transparent linear low density polyethylene is 120°C to 122°C. is. It can be seen from the foregoing that the low temperature heat seal performance of matte linear low density polyethylene is poor. Usually, it is considered to mix with a low-melting resin in order to improve low-temperature heat-sealing performance. However, although the heat-sealing performance is improved, the glossiness is increased and the matte feeling is reduced. Therefore, it is necessary to improve the low-temperature heat-sealing performance while ensuring a matte feeling (glossiness of 9.0 or less). One of the features of the three-layer colored film of the present invention is that the low-temperature heat-sealing performance is improved through the design improvement of raw materials.

In this embodiment, an interlayer ratio of 1.2:2.0:0.8 is adopted for each layer in the three-layer die head, for example, the outer layer is a matte linear low-density polyethylene + opening agent, and the middle layer is a matte Linear low-density polyethylene + colored masterbatch, inner layer matte linear low-density polyethylene + transparent linear low-density polyethylene + high-pressure low-density polyethylene + opening agent, finally maximum gloss It gave off a feeling of extinguishing. The interlayer ratio of the three-layer die head of the three-layer extruder is very important.If the three-layer extruder is not equipped with an extrusion metering control device, the stability of the interlayer thickness of the die head cannot be ensured. If the thickness is not stable, it directly causes a change in matte feeling and an unstable heat seal strength. The three-layer extruder of the present invention is divided into an outer layer extruder, an intermediate layer extruder and an inner layer extruder. Based on the set ratio, the resin between each layer inside the three-layer die head is constant by the automatic extrusion metering control device. extruded in quantity. Normally, without a metering controller, it is not possible to control according to the inter-layer ratio setting. Generally, the interlayer ratio of the three-layer die head for PE film molding is 1:2:1. In order to meet the needs of consumers, the present invention changes the interlayer ratio of the die head of the colored matte film, and the purpose is to achieve the maximum matte feeling (glossiness of 8.0 or less). The feature of the three-layer colored film of the present invention is that the interlayer ratio = outer layer 1.0 to 1.2: middle layer 1.0 to 2.0: inner layer 0.5 to 1.0. It is possible to realize a reduction in glossiness that cannot be achieved by conventional methods.

The three-layer colored film having a matte feel (glossiness of 9.0 or less) of the present invention has the following characteristics.

(1) Light colored masterbatches are generally organic masterbatches. A disadvantage of organic masterbatches is their poor weather resistance, which limits their use. On the other hand, the inorganic light-colored masterbatch has poor adhesion to metals and thus is easily decolored, making it possible to produce a three-layer matte colored film capable of shortening the decolorization time.

(2) Matte feeling (glossiness is 9.0 or less) is inversely proportional to glossiness. To obtain a three-layer matte colored film with excellent low-temperature heat-sealability while maximizing matte feeling (glossiness of 9.0 or less) by adjusting the design of the three-layer raw material resin and the interlayer ratio of the die head. becomes possible.

(3) In the field of sanitary materials, all packaging bags are generally printed on the entire surface. The matte colored film of the present invention not only gives a sense of luxury, but also reduces the printing area, making it a packaging bag that is extremely advantageous in terms of environmental protection.

Although the embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and various changes, replacements, substitutions, and simplifications can be made without departing from the scope and principle of the idea of the present invention. can be implemented by

Claims (4)

A three-layer colored film having a matt feel, the three-layer colored film is composed of an outer layer, an intermediate layer, and an inner layer, and the outer layer is made of the following raw material: 90-98 % by mass of linear low-density polyethylene, 0-7% by mass of high-pressure low-density polyethylene or transparent low-density polyethylene, and 2-3% by mass of an opening agent; 70 to 90% by mass of linear low density polyethylene having a melting point of 127° C., 0 to 10% by mass of linear low density polyethylene having a melting point of 120° C. to 122° C., and 0 to 10% by mass of high pressure low density polyethylene, The inner layer is composed of 10 to 20% by mass of a colored masterbatch ; 27 to 40% by mass of linear low-density polyethylene, 10 to 25% by mass of high-pressure low-density polyethylene , and 2.5 to 4% by mass of an opening agent. A three-layer colored film having a matte feel, which is a masterbatch, wherein the concentration of the inorganic pigment in the colored masterbatch is 20% by mass or less . 2. The three-layer colored film according to claim 1, wherein the three-layer colored film has a glossiness of 9.0 or less. The interlayer ratio of the outer layer, the intermediate layer and the inner layer is outer layer: intermediate layer: inner layer = 1.0 to 1.2: 1.0 to 2.0: 0.5 to 1.0, A three-layer colored film according to claim 1 or 2 . 4. The method for producing a three-layered colored film according to any one of claims 1 to 3 , wherein the resin composition constituting the outer layer, the resin composition constituting the intermediate layer, and the inner layer are composed. A method for producing a three-layer colored film, comprising coextrusion with a resin composition and inflation molding.