CN111703046A

CN111703046A - Method for manufacturing synthetic resin laminated board for commodity packaging tray

Info

Publication number: CN111703046A
Application number: CN202010587791.8A
Authority: CN
Inventors: 徐起源; 姜贤植
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-26
Filing date: 2020-06-24
Publication date: 2020-09-25
Anticipated expiration: 2040-06-24
Also published as: CN111703046B; KR102164466B1

Abstract

The present invention relates to a method for manufacturing a synthetic resin laminate suitable for manufacturing a commodity packaging tray, and more particularly, to a method for manufacturing a synthetic resin laminate for a commodity packaging tray, which has a structure in which a lower layer composed of polystyrene, polylactic acid, and an auxiliary additive and an upper layer composed of polystyrene, polyethylene, sodium bicarbonate, polylactic acid, and an auxiliary additive are laminated, and when the upper layer and the lower layer are co-extruded, a background pattern such as gentle waves or wood rings is formed on the surface of the upper layer due to a difference in fluidity between the upper layer and the lower layer, and the synthetic resin laminate has a soft texture such as paper.

Description

Method for manufacturing synthetic resin laminated board for commodity packaging tray

[ technical field ] A method for producing a semiconductor device

The present invention relates to a method for manufacturing a synthetic resin laminate suitable for manufacturing a tray (tray), and more particularly, to a method for manufacturing a synthetic resin laminate suitable for a tray having a soft texture like paper, in which a lower layer comprising polystyrene, polylactic Acid (PLA) and an auxiliary additive, and an upper layer comprising polystyrene, polyethylene, sodium bicarbonate, polylactic Acid and an auxiliary additive are laminated, and when the upper layer and the lower layer are co-extruded, a background pattern like gentle waves or wood rings is formed on the surface of the upper layer due to a difference in fluidity between the upper layer and the lower layer.

[ background of the invention ]

With the development of industry, the consumption of commodities is expanded, the sales competition is increasingly intense, and the importance of commodity packaging is gradually increased. The commercial packages are generally divided into outer packages and inner packages. The main function of the outer package is to attract the attention of consumers through decoration and provide a commodity identification function, and the inner package has a physical or chemical protection function on commodities according to the characteristics and functions of the commodities.

A commodity packaging tray (tray), which is one type of inner packaging material, is a packaging container that is molded into a three-dimensional structure using styrofoam, paper, or a synthetic resin sheet so as to have a commodity housing portion corresponding to the outer shape of a commodity. The commodity packaging tray can enable commodities to be in fixed positions in the outer container, prevent the commodities from shaking, protect the commodities from external impact, and further play the functions of convenience in commodity display and the like.

A three-dimensional cookie packaging container that can be used when a plurality of cookie foods are sold in a bundle is described in conventional patent No. 10-1018133 (2011, 02, 21), and a product packaging tray in which a product storage space is formed inside a parallelepiped formed by cutting a part of the upper surface of a parallelepiped formed of paper or synthetic resin and folding the same is disclosed in registered utility model No. 20-0468938 (2013, 09, 03).

In addition, various synthetic resin sheets (also referred to as films) have been developed which can be effectively used as materials for commercial packaging trays. For example, patent No. 10-0270480 (08/02/2000) describes a non-stretch, matte laminate film having a polypropylene resin as a core layer and surface layers coextruded on both sides. One surface of the surface layer is formed of a heat-sealable matte layer, and is useful as a food packaging material or a medical packaging material.

In addition, patent No. 10-1429220 (2014, 08/05) describes an extended coextruded film of a multilayer structure in which a heat seal layer and a surface layer are formed on both sides of a center layer composed of a propylene polymer or an ethylene-propylene copolymer, and an intermediate layer is formed at least one of between the center layer and the heat seal layer or between the center layer and the surface layer.

The conventional co-extrusion laminated film as described above has no specific pattern on the surface thereof, and in order to add a certain pattern on the surface thereof, a printed film of PET or PVC is plated on the base film. However, this type of plating of synthetic resin is complicated in the manufacturing process, and particularly, due to the difference in the physical properties, particularly melting point, of the base film and the printed film, the plating of synthetic resin causes delamination, which causes a problem that the plating cannot be reused when discarded after use.

[ Prior art documents ]

[ patent document ]

Patent No. 10-1018133 (2011, 02, 21);

registration utility model No. 20-0468938 (09/03/2013);

patent No. 10-0270480 (08/02/2000);

patent No. 10-1429220 (2014, 08.05).

[ summary of the invention ]

[ problem ] to provide a method for producing a semiconductor device

The object of the present invention is to provide a method for manufacturing a synthetic resin laminate suitable for manufacturing a commodity packaging tray, which is easily recycled and has a soft texture like paper, wherein a background pattern of gentle waves or natural irregularity like a tree ring is formed on the surface of an upper layer to make the commodity image more prominent,

[ technical solution ] A

The method for manufacturing the synthetic resin laminate for the commodity packaging tray of the present invention is preferably a method comprising the steps of: A) a preparation step of a lower layer composition which comprises 65-95 weight percent of polystyrene, 3-30 weight percent of polylactic acid and 2-5 weight percent of auxiliary additive and has a melt index of 3.5-4.5 g/10 min; B) the preparation method comprises the following steps of preparing an upper layer composition which comprises 55-80 weight percent of polystyrene, 5-15 weight percent of polyethylene, 4-17 weight percent of sodium bicarbonate, 2-10 weight percent of polylactic acid and 2-5 weight percent of auxiliary additives and has a melt index of 0.2-1.2 g/10 min; C) co-extruding the lower layer composition and the upper layer composition at a temperature of 190 to 210 ℃ into a laminate in which the lower layer and the upper layer are laminated at a thickness ratio of 8:2 to 9.5: 0.5; D) and cooling and drying the laminated board at the temperature of 20-35 ℃.

[ PROBLEMS ] the present invention

The present invention has an advantageous effect in that the synthetic resin laminate manufactured according to the present invention has a soft texture while the surface of the upper layer is formed with gentle waviness or a natural background pattern like a wood ring at the time of co-extrusion due to the difference in fluidity of the lower layer composition and the upper layer composition and the difference in thickness of the lower layer and the upper layer, and further the surface of the upper layer is rough like paper;

the synthetic resin laminate manufactured according to the present invention is used as a commodity packaging tray, can give a high-grade decorative effect in which the image of a commodity is prominent, and the melting points of the lower layer and the lower layer are substantially similar, and thus, it is easily reused when discarded after use.

[ description of the drawings ]

Fig. 1 to 5 are photographed images of the upper layer surface of the synthetic resin laminate manufactured according to examples 1 to 5 of the present invention;

fig. 6 is a pictorial view showing an example of a cosmetic packaging tray produced using the synthetic resin laminate of example 1.

[ detailed description ] embodiments

The present invention is described in detail below. However, even if the structure necessary for implementing the present invention is not described in detail, what has been described in the prior art or can be easily implemented by those skilled in the art according to the well-known technology is not described in detail.

The method for producing the synthetic resin laminate for a commercial packaging tray of the present invention will be described below with reference to steps A) to D).

The lower layer composition is first prepared in step a). The lower layer composition consists of 65-95 weight percent of polystyrene, 3-30 weight percent of polylactic acid and 2-5 weight percent of auxiliary additive, and the melt index is preferably 3.5-4.5 g/10 min.

The polystyrene is a base resin constituting the laminate of the present invention, is colorless, transparent, and has advantages of excellent water resistance, chemical resistance, and moldability, and is currently widely used as various packaging materials.

The content of the polystyrene in the lower layer composition is not technically significant, but less than 65 weight percent or more than 95 weight percent causes a problem that the background pattern appearing on the surface of the upper layer becomes excessively blurred.

The polylactic acid (PLA) is one of plastic materials manufactured using raw materials extracted from corn starch, and is a very safe and environmentally friendly material in which harmful substances such as environmental hormones or heavy metals are not detected. The product molded using the polylactic acid has physical properties substantially similar to those of a plastic material in use, but has an advantage in that it is rapidly biodegraded by microorganisms when it is discarded after use.

The polylactic acid resin has a defect of slightly weak durability, but has less shrinkage by thermal deformation, and can be precisely injection-molded and formed, and particularly, the outer surface of the commodity packaging tray is roughened in the present invention, so that the texture is soft like paper. The content of the polylactic acid depends on the content of the polystyrene.

The auxiliary additive is a masterbatch type auxiliary additive including a whitening agent, a dispersing agent, and the like, which are common additives, preferably used together with a base resin for a masterbatch and a pigment.

Then the upper layer composition is prepared in step B). The upper layer composition consists of 55-80 weight percent of polystyrene, 5-15 weight percent of polyethylene, 4-17 weight percent of sodium bicarbonate, 2-10 weight percent of polylactic acid and 2-5 weight percent of auxiliary additive, and the melt index is preferably 0.2-1.2 g/10 min.

The composition of the upper layer composition, the same polystyrene and polylactic acid and auxiliary additives as those used for the lower layer composition of the step a) were used.

The polyethylene is a base resin constituting an upper layer together with polystyrene, and chemically reacts with the sodium bicarbonate to roughen the outer surface of the commodity packaging tray, giving it a soft texture like paper.

When the content of the polyethylene is less than 5 weight percent, the surface of the product packaging tray is too smooth to realize the desired texture and touch, whereas when it exceeds 23 weight percent, the surface of the product packaging tray is irregularly formed with minute groove marks such as flame-jet.

The Sodium Bicarbonate (Sodium Bicarbonate, chemical formula NasHCO)₃) Is one of the unique components of the present invention, also called Sodium bicarbonate (Sodium bicarbonate) or baking soda, or bicarbonates.

The sodium bicarbonate is a white crystalline mass or crystalline powder, is easily dissolved in water and hydrolyzed, has the characteristic of slowly generating carbon dioxide at a temperature of about 65 ℃ or higher, and is mainly used as a food additive, for example, for making bread or cookies, to swell the material, to improve the taste and mouthfeel, and to soften it for easy digestion.

However, in the present invention, the polyethylene chemically reacts with the polyethylene to roughen the surface of the upper layer and has a soft texture like paper. The content of sodium bicarbonate depends on the content of polyethylene.

And then C) a step of co-extruding the upper layer composition and the lower layer composition at a temperature of 190-210 ℃ to form a laminate in which the upper layer is laminated on the lower layer, after drying the upper layer composition and the lower layer composition at a temperature of 75 ℃ for about 30 minutes to remove moisture, respectively.

The thickness ratio of the lower layer to the lower layer is preferably 8:2 to 9.5:0.5, the lower layer composition is preferably coextruded at a temperature of 200 ℃ and the upper layer composition is preferably coextruded at a temperature of 195 ℃.

In the synthetic resin laminate of the present invention, the lower layer is much thicker than the upper layer, and the lower layer composition is extruded in a much larger amount than the upper layer composition, so that the lower layer composition is preferably extruded at a temperature about 5 ℃ higher than that of the upper layer composition when the lower layer composition is co-extruded.

If the thickness ratio of the lower layer and the upper layer is less than 8:2 or exceeds 9.5:0.5, a desired pattern does not appear on the surface of the upper layer or delamination phenomenon in which the lower layer and the upper layer are separated from each other may occur.

And D) cooling the laminated board at the temperature of 20-35 ℃, thereby completing the manufacture of the synthetic resin laminated board. Preferably, in said step D) the laminate is cooled by means of a cooling roller.

The laminate manufactured according to the present invention is such that the surface of the upper layer forms gentle waves or natural background patterns like wood rings due to the difference between the melt indexes of the lower layer composition and the upper layer composition and the thicknesses of the lower layer and the upper layer.

That is, the upper layer composition has a much lower melt index than the lower layer composition and the upper layer has a much thinner thickness than the lower layer, so that a difference in fluidity occurs between the lower layer composition and the upper layer composition during the co-extrusion of the lower and upper layers, and due to the difference, the upper layer composition cannot be continuously applied to the lower layer, a phenomenon in which a portion is broken occurs, and further a random pattern such as waves or growth rings is formed on the surface of the upper layer.

And a texture that is rough and soft like paper is achieved on the surface of the upper layer by the physical properties of the polylactic acid resin contained in the lower layer composition and the upper layer composition, and the chemical action of the polyethylene and sodium bicarbonate contained in the upper layer composition.

The following describes embodiments of the present invention. These examples are provided only to further illustrate the present invention, and the scope of the claims of the present invention is not limited to these examples.

[ examples ]

The lower layer composition and the upper layer composition were prepared according to the composition and content (unit: weight percentage) of table 1 below, respectively.

TABLE 1

In Table 1, the master batch used in each example was an M/B dark brown 7838 product of Korean (strain) D plastics. The master batch was composed of a polystyrene resin 82.3 weight percent, a white pigment 4 weight percent, a yellow pigment 1.1 weight percent, a red pigment 0.5 weight percent, a black pigment 0.1 weight percent, and other additives 12 weight percent, and the whole color was pale brown.

The lower layer composition and the upper layer composition of table 1 were dried at a temperature of 75 ℃ for about 30 minutes to drain off moisture, respectively. The lower layer composition and the upper layer composition were then placed in a co-extrusion apparatus, the lower layer composition was co-extruded at a temperature of 200 ℃ and the upper layer composition was co-extruded at a temperature of 195 ℃ to extrude a laminate of 1mm thickness. The laminate is now such that the lower layer has a thickness of up to 0.9mm and the upper layer has a thickness of up to 0.1 mm.

The laminate is then passed between three cooling rolls at a temperature of 25 ℃ or less while being cooled, thereby producing the synthetic resin laminate of the present invention.

The surface states of the respective upper layers of the synthetic resin laminates manufactured according to examples 1 to 5 were photographed, and the results are shown in fig. 1 to 5. Fig. 6 is a pictorial illustration of a cosmetic packaging tray molded using the synthetic resin laminate manufactured according to example 1.

As shown in fig. 1 to 6, the synthetic resin laminate for a commodity packaging tray manufactured according to the present invention has a surface of an upper layer exhibiting a soft texture like paper and a natural background pattern of gentle waviness or woodrings formed, and the background pattern shows a slight difference in morphology depending on the content ratio of each component constituting a lower layer composition and an upper layer composition.

The synthetic tree laminate manufactured according to the present invention has the advantage that the melting points of the base resins constituting the lower layer composition and the upper layer composition are substantially similar, and thus the product is easily reused after being discarded.

In the present invention, commodity packaging trays are used as the synthetic resin laminate manufactured according to the present invention for convenience, but the laminate may be used for other purposes than commodity packaging trays according to the need.

Claims

1. A method for manufacturing a synthetic resin laminate for a commodity packaging tray, comprising:

A) a preparation step of a lower layer composition which comprises 65-95 weight percent of polystyrene, 3-30 weight percent of polylactic acid and 2-5 weight percent of auxiliary additive and has a melt index of 3.5-4.5 g/10 min;

B) the preparation method comprises the following steps of preparing an upper layer composition which comprises 55-80 weight percent of polystyrene, 5-15 weight percent of polyethylene, 4-17 weight percent of sodium bicarbonate, 2-10 weight percent of polylactic acid and 2-5 weight percent of auxiliary additives and has a melt index of 0.2-1.2 g/10 min;

C) co-extruding the lower layer composition and the upper layer composition at a temperature of 190 to 210 ℃ into a laminate in which the lower layer and the upper layer are laminated at a thickness ratio of 8:2 to 9.5: 0.5;

D) a step of cooling the laminate.

2. The method of producing a synthetic resin laminate for a commercial packaging tray according to claim 1,

the auxiliary additives contained in the lower layer composition of the step a) and the upper layer composition of the step B) are a master batch including a polystyrene resin and a pigment, and a whitening agent and a dispersing agent.

3. The method of producing a synthetic resin laminate for a commercial packaging tray according to claim 1,

in the step C), the lower layer composition is coextruded at a temperature of 200 ℃ and the upper layer composition is coextruded at a temperature of 195 ℃.

4. The method of producing a synthetic resin laminate for a commercial packaging tray according to claim 1,

in the step D), the laminated board is cooled by passing through a cooling roller with the temperature of 20-35 ℃.