JPS6018338A - Composite foamed styrene sheet and vessel manufactured by molding said sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel composite foamed styrene sheet and a container made of these sheets, and more particularly to a composite sheet having a matte surface and a textured texture. This invention relates to a composite foamed styrene sheet, which is a container obtained by thermoforming, and a container thereof.

Expanded styrene sheets (hereinafter referred to as PSP) are used for containers, bowls, etc. due to their excellent insulation properties and strong strength.
They are widely used as food containers such as plates, but in recent years there has been a demand for ceramic-like containers with glossy surfaces to differentiate containers and promote sales. There is also a demand for a PSP container that can strongly exhibit a strong bonding effect.

The present invention has been developed to meet these needs. 'ftr That is, the present invention has a structure of at least six layers, the skin layer is made of a mixture of styrene resin and olefin resin, and the core layer is made of styrene resin on one or both sides of the foamed styrene sheet. With only a layer of a mixture of styrene resin and olefin resin, which is a special skin layer characterized by total light transmission through the vaginal core layer, even when laminated with PSP, the surface is Although it exhibits a matte state, the degree of matteness is weak, the sheet has a poor texture in appearance, and its practical strength such as impact strength is weak, so it is difficult to use the molded product for practical purposes. A layer 9 consisting of a mixture of a styrene resin and an inorganic filler as a core layer. Even if it is laminated with PSP, it is difficult to obtain a matte surface, so in the present invention, by laminating PSP and a surface material obtained by combining one thread of a surface layer and a core layer consisting of at least two layers, The present invention has made it possible to obtain a composite foamed styrene sheet 7 which has a matte surface and a curved appearance. Furthermore, this foamed styrene sheet exhibits a very fine printing effect when printed on the surface of a thermoformed product.The structure of the surface layer and core layer, which are the surface materials, is as follows: Even if there are two layers, the epidermal layer and the middle core layer, is there an epidermal layer on both sides of the middle core layer? It may have six layers. In the case of a two-layer structure, the thickness ratio of the outer skin layer and the middle core layer is 5/95 to 5/95.
If the ratio of the skin layer to the core layer is less than 5795, it will be difficult to obtain the desired surface condition, and if it exceeds 5.0150, the strength as a surface material will deteriorate. However, even if it is laminated with PSP and made into a container, its impact resistance is weak and it cannot be put to practical use.

Furthermore, in the case of a 6-layer structure of epidermis/core/epidermis.

Wall thickness ratio is 2.5/95/2.5~:2515
It is preferable to select between 0/25. If the epidermis layer is full, the surface will be less matte, and if the epidermis layer is buried, there will be strength problems similar to the two-layer structure, making it difficult to put into practical use. Sexuality is damaged.

Next, the styrene resin used for the skin layer of the surface material is mainly impact-resistant styrene resin (hereinafter referred to as HI-PS), but in addition to this, styrene resin (hereinafter referred to as GP-PS)
and styrene-butadiene block copolymer (hereinafter referred to as SBR)
The mixing ratio of H-neeps/GP-PS can be changed depending on the practical use, but it should not be used at a ratio of 30/70 or more. is preferable, and H knee PS/GP-P
For S/SBR, 90~60/80~10/30
It is preferable to select from the range of 5 to 5.

On the other hand, the olefin resin used for the skin ff3vc is:
Low density polyethylene (hereinafter referred to as LDPFi), linear dependent density polyethylene (hereinafter referred to as LLDPI), ethylene-vinyl acetate copolymer (hereinafter referred to as EVA), ethylene-ethyl acrylate (hereinafter referred to as EFiA), polypropylene and ethylene-α-olefin A single or mixed random non-polymer resin Z can be used. , the melt flow index (ASTM D-
1238 method), it is suitable to use a method of 0.1 to 15y/10 minutes, preferably 0.3 to 10F/10 minutes, to bring out the effects of the present invention. If the melt flow index is 011P for less than 710 minutes, it will be difficult to mix uniformly with the styrene resin, and if it exceeds 15F/10 minutes, the surface will become insufficiently matte.

Further, regarding the vinyl acetate content of BVA, if the vinyl acetate content is high, eye stain may occur during sheet production, so the vinyl acetate content is preferably 2 Ojk or less. Furthermore, regarding EEA, if the amount of ethyl acrylate is large, the matting effect will be insufficient, so the amount of ethyl acrylate is preferably in the range of 5 to 60% by weight.Next, ethylene-α-olefin random copolymer The α-olefin can be selected from random copolymers of ethylene and propylene, butene, pentene, hexene, etc., but the commercially available product manufactured by Mitsui Petrochemical Industries ■ under the trade name "Tafmer" is suitable. Furthermore, it is possible to use a mixture of two or more of the above-mentioned olefin resins. Next, the weight ratio of styrene resin and olefin resin should be set to achieve the desired matte finish when the amount of olefin resin is small. In addition, if the amount of olefin resin is large, the strength will be weakened, so if the sheet is made into a composite sheet, trimming or scratches will occur when trimming the sheet, and the surface abrasion will increase. The marriage ratio between resin and olefin resin is 9515 to 50150
is suitable.

On the other hand, the core layer is composed of styrene resin! : No 41
, and a filler, and the mixing ratio is expressed by the total penetration rate of the core layer. It is necessary to have a total light transmittance of 71% or less so that a total light transmittance of 65% or less, preferably 60% or less, can be imparted. Further, the total light transmittance criterion 1 may be determined by the thickness of the core layer, the amount of filler, or a combination thereof. If the total transmittance exceeds 35, the composite sheet will have a poor texture and a marbled appearance, which is not suitable for the purpose of the present invention. The styrene resin used for the core layer has the same composition as the skin layer and has no bulk, but in order to improve its compatibility with the inorganic filler, other components such as olefin resin are used in combination. There is no problem at all. Inorganic fillers include commonly used heavy or light calcium carbonate, titanium oxide, clay, talc, mica, and the like. These may be used alone or as a mixture of two components.

Regarding the skin layer, which is the surface material of the present invention, it is fully possible to add antistatic agents, inorganic pigments, etc. for the purpose of imparting other functions. Surface material σ) As a method of obtaining a composite sheet, a method of simultaneously obtaining a composite sheet using the co-pressing d' and ci method is also possible, in which the skin layer and the core 1@? There is no problem even if they are manufactured separately and later bonded together using adhesive to create multiple units.

In addition, the thickness of the surface material must be at least 50 μm, as a thin layer will result in poor combination effect. There is no particular restriction on the upper limit.
The PSP of the present invention can be freely selected based on the practical strength of containers. Next, the PSP VC used in the present invention will be explained. Preferably, it is 7 to 15 times as large.
If the foaming ratio is less than 5 times, the strength will be low and it will be difficult to put it into practical use.
In addition, if the foaming ratio exceeds 20 times, ps
:py, it is difficult to produce it continuously for a long time.

For PSF rhinoceros, 0.5X from the strength of the container.
If it is less than this, the strength will be weak and the container will crack or collapse.71. There are spaces such as

In addition, although there is no need to rule out the upper limit of LZ in terms of physical properties, it can be said that it is preferable to select from 6.0X or less when economical efficiency is considered.

Next, regarding the bonding of PSP and surface material, there are two methods: extrusion lamination, in which the surface material is extruded and laminated to PSP, and thermal lamination, in which the surface material is extruded into a sheet and then bonded to PSP using heat. Even with the conventional laminating method vc, it is possible to laminate without any problem.

Historically, thermoforming of laminate foamed styrene sheets can be done satisfactorily by both vacuum forming, which is the usual method used, and pressure forming. 1 to 4, Comparative Example 40, % extruder (manufactured by Toshiba Machine L/D = 25) 2 units and 6
5X press FJ'-machine (Hayashiba Machine L/D=28) and 6 layers
Using a co-extrusion chain consisting of a chair (width 600 tX), the outer layer of the surface material as shown in the table is made from a 40 mm extruder, and the core JfJ Y
, 65% extruder, and these surface materials and PSP as shown in the table were laminated. The surface properties of the composite foamed styrene sheets obtained are as shown in the table below.
°C, force tI heat time 10 seconds, plug temperature 50 °C, vacuum #7
60 Hg) VC, IL10Xx7DXxSOofXH
A square container and a pressure forming machine manufactured by Kansai Automatic Machinery (temperature 650
℃, plug 130°G, whole mold temperature 40-50℃, heating time 20 seconds, compressed air 5.5KP/===”
The surface appearance of a 60xa round container is molded! l-I looked into it.

In both cases, the surface was matte and had a matte effect, and a molded product with a strong sense of composition was obtained.

i), H knee PS: Styrene resin with impact resistance, manufactured by Denki Kagaku Kogyo ■, trade name "Denka Styrol HI-B-6j"
2), LLDPE: Linear low-density polyethylene, manufactured by Mitsui Petrochemical Industries, Ltd., product name [Ultra Zex, 20
2OL, Melt 70-index 2.1y/10min-
; 3), J Tsuma: Kosenshin α-Orehui 7 Rough
f Mucolu combination, manufactured by Mitsui Petrochemical Industries ■, product name [Tafmer A4C185, melt flow index 4. ,OF
/10 minutes" 4), EVA: Ethylene-vinegar or vinyl copolymer, manufactured by Mitsui Polychemical ■), product name "Evaflex POn
83, vinyl acetate content 15 weight ratio, melt flow index 1.7;
Manufactured by m, product name "SB Red" 6), Ti○2 titanium dioxide, manufactured by Tokyo Ink ■, product name rPs/83y-13-wj The physical property measurements of υ/addition and comparative examples are as follows. , Total penetration rate: 6717 to J-K S-Surface roughness: Made of Kosakakara Tk" Rad 11-, surface appearance 4 words [
Measured at a magnification of 2000 to 10.000 Gloss: J-K5-Z8741, Gloss Digital 4VG
-Type 10 (manufactured by JEOL Ltd.) Appearance: KJIs texture was introduced by visual inspection of the sheet surface.

Patent applicant Denki Kagaku Kogyo Co., Ltd.

Claims (2)

[Claims] (1) On one or both sides of a foamed styrene sheet, the skin layer is made of a mixture of styrene resin and olefin resin, and the core layer is a mixture of styrene resin and inorganic filler, and the core layer is made of a mixture of styrene resin and inorganic filler. A composite foamed styrene sheet formed by laminating a laminated J-Tobi sheet having a total light transmittance of 35% or less. (2) On one or both sides of a foamed styrene sheet, the surface layer is made of a mixture of styrene resin and olefin resin, and the core layer is a mixture of styrene resin and inorganic filler, and the core layer is made of a mixture of styrene resin and inorganic filler. A container made by thermoforming a composite foamed styrene sheet made of laminated layers having a total light transmittance of less than 35 cm.