JPH09123322A - Styrene laminated sheet and its molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to provide excellent shapability and moldability without cut-off of a film at the time of heat molding SOLUTION: This styrene laminated sheet is obtained by laminating a styrene film at least on one surface of a foamed polystyrene sheet. The thickness of the polystyrene sheet is 0.8 to 3.5mm. The styrene film contains a resin composition which indispensably contains resins (A) and (B), and is oriented at least in one direction. The resin (A) is 10 to 90wt.% of the styrene polymer containing at least one type of monomer selected from vinyl aromatic hydrocarbons, and the resin (B) is 90 to 10wt.% copolymer containing 60 to 95wt.% of content of the vinyl aromatic hydrocarbon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated sheet and a molded product thereof which are used for packaging lightweight foods and other articles by molding such as vacuum molding and pressure molding.

[0002]

2. Description of the Related Art Conventionally, as a polystyrene-based laminated sheet for molding, a laminated sheet 5 of a polystyrene film 1 and an expanded polystyrene sheet 3 (hereinafter referred to as PSP) shown in FIG. 1 and a PSP3 shown in FIG. There is known a laminated sheet 5 in which an adhesive resin layer 4 of high-impact polystyrene (hereinafter referred to as HIPS) is provided as an intermediate layer of a polystyrene film 1. These laminated sheets 5 are formed by laminating at least one layer sheet and at least one layer film, and the sheet layer is made of a material having a relatively thick rigidity in order to maintain the shape and strength of the molding container. It is used for film 1. It is made of transparent and glossy material in order to finish the printing container on the back side of the film by printing on the back surface of the film, and to enhance the surface strength of the container. A material that enhances durability is used.

The constitution of these laminated sheets is appropriately selected and used depending on the use of the molding container, but in the container utilizing heat insulation (heat retention, cold insulation) or buffer property, the sheet layer is mainly made of P.
The required functions of the container are satisfied by using SP, etc. Although there are various materials, polystyrene-based resins, which are excellent in rigidity, strength, and price, are often used, and for the film to be laminated on them, similar styrene-based resin films that are advantageous in terms of processing and recycling are selected.

The transparency and gloss of the film 1 are indispensable requirements for making the printed finish of the container beautiful, and PS homopolymer is most suitable, but it is brittle and therefore covers the brittleness. For this purpose, a method of stretching and orienting is generally known. The film thus obtained is called a stretched film (or OPS film) and has transparency,
It has excellent gloss, strength, and printability, but since it is highly oriented and is composed of PS homopolymer, the elongation of the film at the temperature at the time of molding is small. Although draw-formed products can be made, deep-drawing products may cause film breakage during molding, and square-shaped molded products having relatively small R corners do not necessarily have sufficient corners as in the mold. stay up. Therefore, a film obtained by another method that does not stretch and orient, for example, a method in which a generally known PS is mixed with a large amount of a rubber component has a toughness and a large elongation at a temperature at the time of molding. It is known that it is good and that deep drawing can be performed in particular. However, since the blending of a large amount of rubber component significantly impairs the optical properties, the container formed by laminating the films is insufficient in transparency and gloss and it is difficult to finish a beautiful printing container at present. is there.
In addition, the rigidity (stiffness) of the film is lost and the suitability for printing is reduced.

For example, Japanese Examined Patent Publication (Kokoku) No. 63-27072 discloses a sheet in which PSP and polystyrene (hereinafter abbreviated as PS) films are laminated. Since PS and HIPS are mixed in the same amount or more, the film is not transparent. Insufficient and poor gloss, it is difficult to obtain a beautiful printing container. In addition,
According to Japanese Patent No. 16690, a PSP base resin is blended with a rubber component (butadiene rubber, styrene-butadiene rubber, etc.) to improve the formability of the sheet layer, and the film layer is made of high impact polystyrene (HIPS) or polystyrene. Using a mixture with rubber, it gives the same level of stretchability as the sheet layer and improves deep drawability. Furthermore, Japanese Patent Publication 5-548
Japanese Unexamined Patent Publication No. 10 discloses a thermoforming method for a laminated sheet having a three-layer structure. The foam layer and the film layer use a mixed resin of PS and polyolefin to improve rigidity and elongation. However, the transparency and gloss of a film in which resins of different types and different in refractive index are mixed are not necessarily good. JP-A-63-
JP-A-227338 also discloses that a resin of a film composited with a styrene-based stretched sheet uses a mixture of styrene and a styrene-butadiene block copolymer. Although there are many examples of using the rubber component as described above, the moldability can be improved, but on the other hand, problems remain in transparency, gloss and rigidity.

It is also known that the use of a rubber component causes another big problem. That is, since the rubber component is prone to thermal oxidative deterioration, it decomposes to generate gel and the like, which causes problems such as deterioration of film quality and appearance, deterioration of printability, and contamination of manufacturing equipment. , There is a constraint that you cannot put a large amount.

[0007]

DISCLOSURE OF THE INVENTION As a result of diligent studies on the above-mentioned problems, the present inventors have found that a styrene-based film is a polymer composed of at least one monomer selected from vinyl aromatic hydrocarbons and a vinyl fragrance. By using a resin composition in which a copolymer of an aromatic hydrocarbon and an aliphatic unsaturated carboxylic acid ester is mixed at a specific ratio, compatibility with PSP is good, separation and recycling are not required, and quality deterioration due to gel etc. occurs. Printing film which is free from defects, has excellent transparency, gloss and rigidity, has a large elongation at the temperature during PSP molding, and has a small apparent tensile elastic modulus at the same temperature, and does not become a deformation resistance of the PSP during molding. By stacking film for film, even in deep-drawing products, there is no film breakage during thermoforming, and good moldability with excellent moldability It found that can provide a styrene-based laminate sheet and its molded body.

[0008]

That is, the first aspect of the present invention
The invention is a laminated sheet obtained by laminating a styrene-based film on at least one surface of an expanded polystyrene sheet,
The expanded polystyrene sheet has a thickness of 0.8 to 3.5 mm
The styrene-based film is a film made of a resin composition containing the following resins (A) and (B) as essential components and stretched in at least one direction, and has an apparent appearance measured at 120 ° C. according to ASTM-D882. Tensile elastic modulus is 0.0
5 to 1.00 kg / mm ² , the tensile elongation is 100% or more, and the tensile elastic modulus measured at a temperature of 23 ° C. is 230 to 28.
0 kg / mm ² and 80 in a hot air circulation oven
A styrene-based laminated sheet having a longitudinal and lateral thermal shrinkage ratio of -5 to 5% and a thickness of 10 to 80 µm when heated at 10 ° C for 10 minutes. (A) Vinyl aromatic carbonization At least 1 selected from hydrogen
Styrene-based polymer 10-90 containing a seed monomer as a main component
(B) Copolymer of vinyl aromatic hydrocarbon and aliphatic unsaturated carboxylic acid ester (B) 90 to 10% by weight of a copolymer containing 60 to 95% by weight of vinyl aromatic hydrocarbon. A second invention is a molded product made of the above styrene-based laminated sheet.

In describing the contents of the present invention below,
First, the common points between the first invention and the second invention, and the background of the common invention will be described. The point that the first invention and the second invention are common and different from the prior art lies in the combination of (a) to (e) below. (A) The styrene-based film of the present invention is made of a resin that includes the following (A) and (B) as essential components, and (A) is 10
˜90 wt%, (B) 90 to 10 wt%, and stretched in at least one direction.

(A) is a styrenic polymer containing as a main component at least one monomer selected from vinyl aromatic hydrocarbons. (B) is a copolymer of vinyl aromatic hydrocarbon and aliphatic unsaturated carboxylic acid ester, and the content of vinyl aromatic hydrocarbon is 60 to 95% by weight.

(B) The styrene film of the present invention has an apparent tensile elastic modulus of 0.05 to 120 at a temperature of 120 ° C.
Must be 1.00 kg / mm ² . (C) The styrene film of the present invention has a tensile elongation of 100% or more at a temperature of 120 ° C. (D) The styrene film of the present invention has a tensile elastic modulus of 230 to 280 kg / mm ² at a temperature of 23 ° C.

(E) The styrene-based film of the present invention has a thermal shrinkage of -5 to 5% in both length and width at a temperature of 80 ° C. First, there are three meanings that the styrene film of (a) is composed of the above composition ratios of (A) and (B). That is,
First, the compatibility with the PSP of the sheet layer is good, secondly, the compatibility of (A) and (B) is good, the transparency and gloss of the film are excellent, and thirdly, gel is easily formed during film processing. Since it does not contain a thermoplastic rubber, there is no concern about gelation, and these three meanings bring out the effect of finishing the printing beautifully.

The apparent tensile elastic modulus of (b) is from 0.05 to
Means to be 1.00 kg / mm ² is in order to adjust the mold depends, lower zone to impair the aesthetics increases transcription of the surface irregularities of the die, the upper region is often rounded corner portion. (C) The tensile elongation of 100% or more means a region in which good moldability is obtained, and the lower limit region means that the film is often broken during molding.

(D) Tensile elastic modulus of 230 to 280 kg /
The meaning of mm ² is to ensure the running suitability and printability of the film during the printing process, and the lower limit region is soft and lacks stiffness, while the upper limit region is too rigid and machine adjustment is difficult and printing is difficult. Cause misregistration. It also means that proper film stiffness is also effective in increasing the strength of the molded product.

The fact that the heat shrinkage ratio of (e) is -5 to 5% in both length and width is to improve the finish of the film when laminating, and if the lower limit and the upper limit are not satisfied, wrinkles of the film frequently occur. I mean. Further, (a) to (e) will be specifically described. First, the resin composition comprising (A) and (B), which is the requirement of (a), has (1) good compatibility with PSP, (2) transparent and good gloss, and (3) no gel formation. Is an important requirement for satisfying the three characteristics of
The film composed of (A) a styrene polymer and (B) a copolymer of a vinyl aromatic hydrocarbon and an aliphatic unsaturated carboxylic acid ester is particularly excellent in transparency and gloss of the resin itself, and The resin composition has improved toughness as compared with polystyrene homopolymer, and it is not necessary to add a large amount of a rubber component that hinders transparency and the like. Further, since it is a film made of the resin composition, it is possible to provide an excellent film without any fear of poor transparency, poor gloss, and gel formation. Therefore, excellent printability can be secured without loss of surface smoothness due to the gel, and the contamination of the production facility due to the gel and the decrease in production efficiency can be completely eliminated.

The mixing weight ratio of the styrene polymer (A), the vinyl aromatic hydrocarbon copolymer and the aliphatic unsaturated carboxylic acid ester copolymer (B) is from 10/90 to 90/10. If the styrene-based polymer (A) is less than 10% by weight, there is no problem in moldability, but there is a problem because the film after molding has wrinkles in appearance (mold release is poor and unevenness occurs on the surface). On the other hand, if it exceeds 90% by weight, the elongation of the film becomes extremely poor, and the film may be broken in the molded product, or many mold deficiencies may occur. Further, the content of the vinyl aromatic hydrocarbon in the copolymer (B) of the vinyl aromatic hydrocarbon and the aliphatic unsaturated carboxylic acid ester is in the range of 60 to 95% by weight so that a good molded article is finished. What is important above is that if the content is out of this range, the film forming property of the film is deteriorated, and a problem occurs during lamination. For example, if it is less than 60% by weight, the softening temperature is too low, resulting in insufficient rigidity of the film and a blocking phenomenon, and if it exceeds 95% by weight, the softening temperature shifts to a high temperature side, so that the elongation of the film remarkably deteriorates.

Further, the fact that the film is stretched in at least one direction enhances the flatness and strength of the film, which is particularly useful for preventing film breakage and printing defects during printing processing and the like. There is. Also, the apparent tensile elastic modulus of the film, which is the requirement of (b), is an important characteristic for the mold determination in molding, and it is possible to perform molding along the molding die by providing appropriate elasticity (waist). I am satisfied with that. If it is less than 0.05 g / mm ^2, it is too soft and irregularities of the mold are picked up to cause surface roughness, resulting in 1.00
If it exceeds kg / mm ² , the corners of the mold are rounded and a so-called improper mold determination occurs.

Next, the tensile elongation of the film, which is the requirement (c), is an important requirement for satisfying the moldability. If the elongation of the film at the heating temperature during molding is not 100% or more, the laminated sheet is obtained. As a result, a good molded product cannot be obtained. The stretch of a conventional stretched transparent film is about 70%, and the stretched transparent film containing a small amount of rubber (4% in terms of butadiene) is about 90% within a range that does not impair the transparency. Only a container can be molded, and a deep-drawing container with a complicated shape cannot be molded. If it is less than 100%, the film is often broken.

Further, the tensile modulus of elasticity, which is the requirement (d), is intended to strengthen the rigidity of the film in order to secure mechanical suitability during printing and to impart strength and rigidity to the molded container. If it is less than 230 kg / mm ^2, it is too soft and running defects during printing processing and ink misregistration frequently occur, and the reinforcing effect of the molding container cannot be expected. 280
If it exceeds kg / mm ² , the stiffness is too strong and mechanical adjustment of the tension during printing is difficult, resulting in misregistration.

Finally, the heat shrinkage rate, which is the requirement of (e), is
Considering the suitability for laminating and the finishability, there is an aim to avoid the expansion and contraction of the film at the time of heat-bonding to prevent the occurrence of wrinkles. If it is less than -5%, the expansion is large, and if it is more than 5%, the contraction is large and wrinkles are likely to occur. The present invention was able to satisfy practically useful properties such as transparency, printability, laminating property, and moldability by combining the above five requirements (a) to (e).

The vinyl aromatic hydrocarbon used in the styrene polymer (A) of the present invention is mainly styrene or α-.
Examples thereof include alkyl-substituted styrenes and nuclear halogen-substituted styrenes. A typical example of the styrene-based polymer composed of the components is polystyrene resin (GPPS). HIPS in which rubber is grafted to these resins for another purpose (such as prevention of film blocking rather than imparting film elongation) or a block copolymer of butadiene and styrene (SBBC) does not impair transparency. If the amount is within the range (about 10% or less of the total resin), there is no problem even if compounded.

Copolymer (B) of vinyl aromatic hydrocarbon and aliphatic unsaturated carboxylic acid ester used in the present invention
Vinyl aromatic hydrocarbons are mainly styrene, α-
At least one kind may be selected from α-alkyl-substituted styrenes such as methyl styrene, nuclear halogen-substituted styrenes, and nuclear alkyl-substituted styrenes according to the purpose. Also,
Aliphatic unsaturated carboxylic acid ester is mainly (meth)
Acrylic ester derivatives, specifically, esters with alkyl alcohols (C1 to C12) such as methyl (meth) acrylate, ethyl, propyl, butyl ..., Esters with alkylene oxides, alicyclic alcohols And the like, and at least one kind is selected from these.

The copolymer (B) used in the present invention is disclosed in JP-B-3-12535, JP-B-3-18813,
JP-B-3-18814, JP-A-4-57845, JP-A-4-59833, and JP-A-4-638.
38, JP-A-4-63839, JP-A-7-
Known resins described in JP-B-82387 and JP-B-62-25701 can also be used as long as other physical properties are satisfied.

As the copolymer (B) used in the present invention,
A copolymer of styrene and butyl acrylate, a copolymer of styrene and ethyl acrylate, or the like is preferable because of the availability of these monomers and the cost advantage and the like. Examples of (B) include special polyfunctional radical initiations disclosed in, for example, Japanese Patent Application Laid-Open Nos. 4-149211 and 4-149212, in addition to copolymers polymerized with a general radical initiator. Copolymers with agents are also preferred.

Styrene-based polymer (A) used in the present invention
As a method for mixing the resin composition of the copolymer (B) and the resin composition (B), a commonly known method such as dry blending or kneading can be used. The expanded polystyrene sheet used in the present invention is known as PSP (polystyrene paper) with a general name of about 3 to 15 times (density of 0.35 to 0.06 g / m 2).
A commercially available product having a relatively low expansion ratio of about 1) may be used. The thickness is selected from the range of 0.8 to 3.5 mm depending on the application. If it is less than 0.8 mm, the structural strength of the molding container is insufficient, and if it exceeds 3.5 mm, not only the thickness becomes thick and the effect of the film remarkably decreases, but also the moldability deteriorates. Also, P
If the foaming density of SP is less than 0.35 g / ml, the characteristics as a foamed sheet are difficult to be exhibited, and if it exceeds 0.06 g / ml, secondary foaming becomes severe at the time of molding and it becomes difficult to obtain a good molded body.

The resin for the expanded polystyrene sheet is mainly polystyrene, but impact-resistant polystyrene containing a small amount of rubber component in polystyrene can also be used, and one of these polymers may be used depending on the purpose. You may combine more than one kind. The method for producing the expanded polystyrene sheet can be either a generally known method of extrusion foaming or a method of foaming a foamable sheet by post-heating, but the method of extrusion foaming with a T-die is often used from the viewpoint of productivity and economy. To be done.

As a method for producing the styrene film used in the present invention, a well-known general production method may be used, and an extrusion inflation film formation method, an extrusion sequential biaxial stretching film formation method using a tenter, etc. are industrially often used. It is a method of stretching in at least one direction. The reason for stretching in at least one direction is that the first is to improve the flatness of the film (reduction of uneven thickness, elimination of surface roughness), and the second is to increase the strength of the film. By improving the above, it is possible to dramatically improve the processability of the two processes of printing and lamination, which are indispensable in the present invention. That is, the stretched film is useful for preventing film breakage and film wrinkles during lamination processing (smooth film does not show wrinkles), and in printing processing it has a good finish (preventing ink misregistration and ink uneven coating). Therefore, it is useful for improving productivity (stable running of the film, prevention of film breakage).

The thickness of this film must be 10 to 80 μm. If it is less than 10 μm, it is too thin and often breaks during processing such as printing or lamination.
If the thickness exceeds 80 μm, the heat capacity of the equipment does not follow up, the stacking speed must be reduced, and the economy is deteriorated. 20 to 40 μm is preferable from the viewpoint of processing speed, economic efficiency, processing suitability and the like.

It is important for the present invention that the stretched film has good transparency and gloss, and the transparency is measured by AS.
The measured value by the haze measurement method based on TM-D1003 is preferably 3.0% or less, and the gloss is measured by ASTM-D.
The measured value by the gloss measurement method based on 2457 is 140%.
The above is preferred. When the haze value exceeds 3.0%, the transparency of the film is deteriorated, and it is not clear even when printed, which is not preferable. If the gloss value is less than 140%,
The gloss of the film deteriorates and the gloss of the film surface disappears even when it is used as a molding container.

The method for producing the laminated sheet in the present invention may be any of the generally known methods for laminating by heating. Typical laminating methods are a thermal laminating method (thermal laminating method) in which pressure is applied by a hot roll, an extrusion laminating method of PSP (extrusion laminating method), and a HIPS resin is melt-extruded and laminated between a sheet and a film. The extrusion sand laminating method (commonly called the sand laminating method) and the like are known.

The hot laminating method is economical because it does not require the use of an adhesive because it is styrene-based, but when laminated with PSP, P
Since the surface irregularities of SP also appear on the film surface, the surface is rough and the appearance is not good. Since the sandrami method eliminates the surface roughness, the surface is smooth and has a beautiful luster, which increases the cost, but is often used for containers and the like that require a high-class feeling. As the HIPS resin for the sandrami method, general impact-resistant polystyrene can be used alone or in a mixture with other resins. HIPS resin is a rubber-modified styrenic polymer containing a rubber-like polymer as dispersed particles,
A cross-linked graft rubber-modified styrene polymer having a dispersed particle diameter of 2 to 10 μm and a cross-linking degree of 65% or more is used, but there is no particular limitation.

As described above, the laminating method is selected according to the purpose of use, but the above-mentioned method is generally widely used for reasons such as productivity and economy. Other methods other than this may be used. In the present invention, the method of printing on the film may be any method generally known for printing inks for styrene-based films. For example, multicolor printing such as clavia printing and flexo printing is often used. In this case, if a large amount of a strong solvent for polystyrene such as methyl ethyl ketone, toluene, ethyl acetate is used, the film becomes brittle, the strength is lowered, or the film does not stretch, so for example, a poor solvent such as isopropyl alcohol or methanol is used together. It is known that the film characteristics are retained.

The molded product comprising the laminated sheet of the present invention is excellent in transparency and luster, is a deep-drawn molded product or a molded product having a good mold definition, and is therefore excellent in molding cycle and molding cost. The specific contents of the film physical property measuring method used in the present invention are shown in the following (1) to (6), and the reference physical property measuring method of the resin used is shown in (7) to (9).

(1) Apparent tensile modulus: ASTM-D
882. Measured in an oven at a temperature of 120 ° C,
The stress Y at 50% elongation of the stress-strain curve shown in FIG.
(Kg), initial stress Y ′ (kg), and initial cross-sectional area a (mm ² ) of the sample, the apparent tensile elastic modulus is calculated based on the following equation, and the measured value is displayed in kg / mm ² . Sample size is 5 cm in length (distance between chucks), width 10 mm,
Tensile speed 50 mm / min, heating time 2 min.

Apparent tensile elastic modulus = {(Y−Y ′) ×
(100/50)} / a (2) Tensile elongation: In accordance with ASTM-D882. It is expressed in% elongation of the sample measured in an oven at a temperature of 120 ° C. The original length is 5 cm, which is the distance between chucks, and the width is 10 mm. Tensile speed 50 mm / min, heating time 2 min.

Elongation% = {(length before breaking-original length) / original length} × 100 (3) Tensile elastic modulus: according to ASTM-D882. Stress y at 2% elongation of stress-strain curve measured at a temperature of 23 ° C
(Kg) and the initial cross-sectional area a (mm ² ) of the sample, the tensile elastic modulus is calculated based on the following equation, and the measured value is expressed in kg / mm ² .

Tensile Elastic Modulus = {y × (100 ÷ 2)} ÷ a (4) Heat Shrinkage Rate: Heated at 80 ° C. for 10 minutes in a hot-air circulation type oven and immediately placed in an atmosphere of 23 ° C. for 5 minutes, and then Measure the dimensions of the sample vertically and horizontally. Heat shrinkage% = {(length after heating-original length) ÷ original length} x 100 The original length is a square with a length of 100 mm and a width of 100 mm.

(5) Haze: Displayed in% by the haze measuring method according to ASTM-D1003. (6) Gloss: According to ASTM-D2457. The incident reflection angle is 45 degrees. (7) Vicat softening temperature: According to ASTM-D1525. The load is 1 kg and the temperature rise rate is 2 ° C./min.

(8) MFR (melt flow rate): A
It is measured under the G condition of STM-D1238 (200 ° C., 5 kg) and displayed in g / 10 minutes. (9) Melt viscosity: 25 ° C. in toluene containing 10% by weight of solute
Canon Fence Viscosity Tube No. Measured at 200,
Displayed in cps. It is an indicator of molecular weight.

Further, the evaluation method and evaluation scale of the film used in the present invention are as follows. The symbols used for the scale are determined as follows. A: The best level. Especially excellent in quality. ○: Practically good level. Δ: A level at which some problems occur in practical use.

X: A level at which practical problems remain. (A) Number of gels in the film: 0.2 mmφ, which is the size seen in the deflector in a film of size 0.5 m × 2.0 m
The number of gels, decomposed products, and foreign substances is measured (n = 3). ◎: 0 to 15 pieces ○: 16 to 30 pieces △: 31 to 60 pieces ×: 61 pieces or more (b) Printability: Gravure roll printing machine (roll width 80
cm, roll diameter 10 cm, speed 80 m / min), and a test film with a width of 64 cm was applied to three gravure roll plates (plate depth 38 μm, 22 μm, 6 μm, all 1
Three colors of 75 lines / inch) are printed. The printing ink is gravure ink XGS- manufactured by Sakata Inx Co., Ltd.
820 Ai 800, XGS-810 White 120, XGS-8
20 ink 1000 was used. The printability was evaluated for the following four items (ink splattering, appearance aesthetics, register misalignment, and film running property), and the following evaluation scales were used. The printability is judged by the comprehensive evaluation of 4 items.

Ink jump: The number of large ink jumps of 0.8 mmφ or more is measured in 10 m ² , and
The smaller the amount of foreign matter such as gels and decomposed products in the film, the better the printability. ◎: 20 pieces or less ○: 21 to 40 pieces △: 41 to 100 pieces ×: 101 pieces or more ・ Appearance of appearance: Observing the cleanness of printing as seen through the film surface, the film may be opaque If it is not glossy, the appearance will be poor. ◎: The transparent gloss is excellent and the finish is good. It is used to judge how well the printed pattern matches with, such as meandering, and the quality of the film (uneven thickness, softness, waist, etc.) can be determined.

⊚: There is no misregistration ○: There is some misalignment, but there is no problem in practical use. Can be corrected by adjusting the equipment △: Misregistration is noticeable and cannot be corrected by adjusting the equipment ×: Misalignment of vertical and horizontal registration is not possible. ・ Film running property: Machine suitable for printing such as film break or meandering after running for 1,000 m. The characteristic of the film is judged to be good or bad (rigidity, uneven thickness, strength and elongation, etc.).

⊚: No film breakage or meandering ○: No film breakage, a slight meandering but no problem in practical use Δ: Film breakage occurs once or twice. There is also meandering ×: The film is broken three times or more. There is also meandering ・ Comprehensive evaluation of printability: The judgment of the above 4 items is determined according to the following criteria.

⊚: 3 to 4 ◎ pass level ○: 1 to 2 ⊚ (no Δ, ×) Pass level Δ: 1 to 4 ∘ (no x) Fail level × : Poor level with 1 to 4 x (c) Lamination suitability: The wrinkles caused by uneven thickness or shrinkage of the film when laminating deteriorates the finishability, so the smaller the better. Also, it is preferable that there is no film breakage, film meandering, or film melting. The determination of wrinkles is represented by the number of wrinkles observed with the naked eye in the size of the laminate sheet having a width of 63 cm and a length of 5 m.

⊚: No wrinkle ○: 1 wrinkle Δ: 2 to 5 wrinkles, film breaks, meandering, and difficult to adjust lame ×: 6 wrinkles or more, film breaks, meandering, film melting (d) Molding Suitable range (area where film breaks, wrinkles, and secondary foaming do not occur): With a vacuum forming machine (sheet width 630 mm, heating zone 2 zone, far infrared heater radiant heating method),
The mold for moldability evaluation shown in the plan view of FIG.
1, 0.2, 0.3, 0.4, 0.5, molds with container body angle θ of 10, 20, 30 degrees), and vacuum forming test (without plug assist) There are four temperature ranges (230, 240, 2 for extrusion sand lamination)
50, 260 ° C., 200, 210, 220, 230 ° C. in the case of thermal lamination and double-sided thermal lamination), film breakage when molding is carried out in a molding time of 5 seconds / zone,
Judgment is made on the extent of the range in which a molded container with good moldability in which molding wrinkles and secondary foaming of PSP are not seen is obtained.

In the molding test, n = 4 shots are molded under one condition, and the average value (width) is displayed. FIG.
6 to 6 are A- in FIG. 4 (plan view of mold for evaluating moldability)
3A and 3B are cross-sectional views taken along the lines A ′ and BB ′, respectively, and the above-mentioned aperture ratio is Lh / Lm shown in FIGS.
And the angle of the body of the container is indicated by θ. Also,
FIG. 7 is an explanatory view showing the molding range. That is, when the relation between the above-mentioned drawing ratio and the set temperature of the heater is taken, it shows the range in which a well-defined molding container in which film breakage, molding wrinkles, and secondary foaming of PSP are not obtained is obtained. The range is represented by the number of square sections 7, and the larger the number of square sections, the wider the molding range. The number of squares is represented by a total of three types in which the container body angle θ is 10, 20, and 30 degrees.

⊚: The molding temperature, molding time, and deep drawing are all wide and the best. Number of compartments 50-60 ○: Molding is good, but molding range is moderate. Number of compartments 40 to 49 Δ: Moldability is rather narrow and molding is difficult. Number of sections 2
4-39 x: The suitability range is narrow due to film breakage, secondary foaming, etc. Number of compartments 0 to 23 (e) Deep drawability: Expressed by the maximum drawing ratio of a good molded product obtained under the optimum conditions (temperature, time) in the above molding test method, and a standard to see how deeply the deep drawing can be done. To The aperture ratio is a value calculated by the following equation from FIG.

Aperture ratio = die depth Lh / die long side length L
m ◎: 0.5 ◯: 0.4 △: 0.3 ×: 0.2 or less (f) Mold regularity: Shows the degree of the mold regularity with respect to the mold, and is the container obtained in the above-mentioned molding test. Visually observe the particularly severe bottom part of the. For the target sample, select the best molded product and examine it.

⊚: Molded as the mold did not transfer the irregularities on the surface of the mold. ◯: Molded almost as it was Δ: It was a mild mold. Or irregularities on the surface of the mold can be seen. ×: Does not conform to the mold. (G) Uneven thickness of the molded product: Expressing as a ratio how much the film layer becomes thinner at the corner than the original thickness before molding at the corner. However, if the ratio is large, it means that the film locally expands and the uneven thickness is large, and it is good that the entire film stretches uniformly. ⊚: 0.31 or more O: 0.26 to 0.30 Δ: 0.21 to 0.25 ×: 0.2 or less (h) Film breakage of molded product: Visual inspection of container obtained in the above molding test Express the situation of running out of film. It is good that there is little or no film break. Temperature 4 levels × drawing ratio 5 levels = 20 The number of film breaks out of 20 is shown.

◎: 0 pieces ○: 1 piece Δ: 2 to 5 pieces ×: 6 pieces or more (i) Molding temperature range: In the above molding test, the drawing ratio was 0.1.
How wide the temperature range that can be molded by 3 or more is expressed by the temperature range (width). The wider the temperature range, the easier the molding temperature can be adjusted, which means that the moldability is good and the molding defects are small.

⊚: Width of 30 ° C. or more ◯: Width of 20 ° C. Δ: Width of 10 ° C. ×: Almost no width (j) Overall evaluation of moldability: (c) to (h) above ) The 6 items of comprehensive judgment are defined by the following criteria.

⊚: 4 to 6 ◎ (no Δ, ×) Pass level ◯: 2 to 3 ◎ (no Δ, ×) Pass level Δ: 1 to 6 Δ (x No) Rejection level x: 1 to 6 x disqualification level (k) Appearance of appearance of molded container (transparency and gloss): Printing of molded container is clean in the above molding test By observing from the outer surface of the film whether it is made, it is preferable that it has excellent transparency and gloss. This shows the same tendency as the transparency and gloss of the film, but there are some cases in which the transparency and gloss are deteriorated by molding, so observe it to confirm it. Printing is done on the back side of the film and observation is done from the front side.

⊚: Both transparency and gloss are good, and the printing finish of the molding container is excellent. ○: Transparency and gloss are also good. △: Transparency is slightly good, but no gloss. ×: Both transparency and gloss are bad.

[0055]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[0056]

Example 1 and Comparative Example 1 The styrene-based polymer (A) was selected from the three resins (PS-1, 2, 3) shown in Table 1, and vinyl aromatic hydrocarbon and aliphatic unsaturated carboxylic acid. Eight types of resins shown in Table 2 were prepared for the copolymer (B) with ester. Further, one type of styrene-butadiene block copolymer (SBBC) resin (SB-1) was prepared and shown in Table 1. The above-mentioned polymer (A) and copolymer (B) and S
B-1 was blended in the resin mixing ratios shown in Tables 3 and 4, mixed in a blender, and then melt-mixed in an L / D = 32 65 mmφ extruder having a kneading and mixing head, and 18 types of pellets were mixed. Got

Films of the various pellets thus obtained were formed by various methods shown below under the conditions shown in the column of film forming method in Tables 3 and 4, respectively. J1
.About.J7 and 11 types of H1 to H11 in the comparative example, a total of 18 types of films were obtained. The film forming conditions (resin temperature, draw ratio) and film thickness are shown in Tables 3 and 4.

Inflation film forming method: L / D = 45
The tube extruded by an extruder with a circular die having a screw of 60 mmφ is inflationed, cooled, and wound into a desired film. In this case, the film thickness is appropriately adjusted by the die slit and the draw ratio. If the resin temperature is largely shifted to the high temperature side, a low orientation, commonly known (low) stretched film can also be obtained.

Tenter sequential biaxial stretching film forming method: L / D =
A parison extruded from a T-die with an extruder having 32 screws of 65 mmφ is stretched by a roll heating type longitudinal stretching machine, transversely stretched by a tenter and cooled, and then the film is wound to obtain a desired film. The thickness of the film is appropriately adjusted by the die slit and the draw ratio.

Calender uniaxially stretched film forming method: L / D = 3
The parison extruded from the T-die by an extruder having a 65 mmφ screw of No. 2 is stretched by a roll heating type longitudinal stretching machine, then cooled and wound to obtain a desired film. The thickness of the film is appropriately adjusted by the die slit and the stretching ratio.

Each of the obtained films was measured for the physical properties of 6 items (apparent tensile elastic modulus, tensile elongation, tensile elastic modulus, heat shrinkage, haze, gloss) and gel number by the physical property measuring method described above. . As a result, Examples are shown in Table 5 and Comparative Examples are shown in Table 6.
From Table 5, No. The physical properties of the films J1 to J7 were excellent in the properties to be provided as a laminating film. It can be seen that the expected level is satisfied with particularly important optical properties such as haze and gloss and the small amount of gel. On the other hand, in Comparative Example No. H1 to H3
It can be seen that the physical properties of the H6 to H10 films are not balanced with the desired physical properties due to the resin itself and the resin composition.

For example, in H1 to H3, since the copolymer (B) is out of the range of the present invention, other physical properties (apparent elastic modulus, tensile elongation, tensile elastic modulus, heat shrinkage rate) are obtained even though the optical properties are good. )
Is not satisfied. Since the film thicknesses of H4 to H5 are out of the preferable range, it is found that when the thickness is thin, the tensile elongation is insufficient, and when the thickness is thick, the haze is insufficient, which is inconvenient. H6 ~
Since the resin composition of H10 is out of the preferable range, only an unbalanced film having advantages and disadvantages in apparent elastic modulus, tensile elongation, tensile elastic modulus, and thermal shrinkage can be obtained. H10
Because of low stretching (low orientation), the thickness variation is large. Further, it can be seen that when a large amount of rubber component such as H9 to 11 occurs, gel generation and optical characteristics (haze, gloss) deteriorate.

[0063]

Example 2, Comparative Example 2 Seven kinds of films of Example 1 and 11 kinds of films of Comparative Example 1 were printed by the method described above,
The printability of the obtained film was evaluated. The results of Examples are shown in Table 7, and the results of Comparative Examples are shown in Table 8. From the table, the film No. of the example. While the printability of J1 to J7 (evaluation of four items of ink splattering, appearance aesthetics, misregistration, and film runnability) exhibited desired performance, the film Nos. Of Comparative Examples were used. It can be seen that the printability of H1 to H11 is insufficient and the unbalanced characteristics of the film hinder the printing process and the finishability.

For example, in H1 to H3, the copolymer (B) is a resin not included in the present invention, and in H1 to H2, the tensile modulus is too large and H3 is too small, which may cause misregistration or film breakage. ing. Since H4 to H5 are out of the preferable range of the film thickness, if the film is thin, running of the film is cut off, and if it is thick, the appearance is deteriorated. It can be seen that H6 to H10 have a resin composition outside the preferable range, and H6 to H8 have less gel and have better optical characteristics, and thus have no ink jump and have a good appearance, but have insufficient processability. On the contrary, H9 ~ H
In the case where a large amount of rubber is mixed as in No. 11, ink splattering often occurs. In addition, a film having a large thickness variation such as H10 has a poor running property (such as meandering) and a large amount of misregistration, and uneven printing of the ink is observed.

[0065]

[Example 3 and Comparative Example 3] A total of 18 types of films obtained in Example 2 and Comparative Example 2 (Experiment Nos. 1 to 7, ratio 1 to ratio 1)
With respect to 1), a laminating process and a forming test were carried out to evaluate them. First, regarding lamination, as shown in Table 9 and Table 10, P is laminated for each film.
A laminated sheet was prepared by selecting the type of SP, the thickness, and the laminating method. The laminating method was performed by the following two methods (a thermal laminating method and a sand laminating method).

Thermal laminating method: A thermal laminating machine equipped with a thermocompression-bonding roller (dielectric heating roll having a roll surface temperature of 198 ° C., diameter 400 mm, roll width 1.3 m, roll speed 10 m / min) by selecting a film and PSP. Laminate. The thermocompression rolls are installed on the top and bottom, so both single-sided and double-sided laminating can be done in one pass. Further, the laminating of the thick film or the thin film is adjusted by raising or lowering the temperature of the heating roll.

Extrusion sand laminating method: film and P
Select SP and use 780 for 90mmφ extruder with L / D = 36
HI with an extrusion sand laminator with a mm width T-die
Immediately after the PS resin (PS-3) is melt extruded and the resin having a temperature of 185 ° C. is extruded in the middle of the PSP and the film, the PS resin (PS-3) is pressure-bonded with a cooling roll and laminated at a speed of 10 m / min. At this time, the thickness of the HIPS layer to be extruded is adjusted to be 100 μm on average.

Experiment No. 2 of the second embodiment. For the printing films of Nos. 1, 2, 3, and 4, PSP having a thickness of 2.3 mm (# 60 manufactured by Pearl Package Co., Ltd., foaming density 0.09 g / ml, width 630 mm) and extrusion sand laminate were used. 5 has a thickness of 2.1 mm PSP (Pearl Package Co., Ltd.)
# 70, foam density 0.11 g / ml, width 630 mm)
And a single-sided heat laminate with No. 6 has a thickness of 3.0
Double-sided thermal lamination with PSP (Pearl Package Co., Ltd. # 90, foam density 0.10 g / ml, width 630 mm) of No. 7, PSP with a thickness of 1.8 mm
(Pearl package # 50, foam density 0.09
g / ml, width 630 mm) and single-sided heat lamination was performed to obtain each laminated sheet of Example 3.

In addition, in Experiment No. 2 of Comparative Example 2. The printing films of the ratios 1 to 9 have a thickness of 2.3 mm PSP (# 60 manufactured by Pearl Package Co., Ltd., foaming density 0.09 g / ml,
630 mm width extruded sand laminate with the same ratio of 10
-11, PSP (Pearl Package Co., Ltd. # 70, foam density 0.11 g / ml, width 63) with a thickness of 2.1 mm.
0 mm) and one-sided heat lamination was performed to obtain each laminated sheet of Comparative Example 3. Lamination suitability of these laminated sheets in the laminating process was evaluated, and the results of the examples are shown in Experiment No. 9 of Table 9. 8 to 14 show the results of the comparative example in Experiment No. Ratios 12 to 22 are shown respectively.

Experiment No. of the example. The laminating suitability of Nos. 8 to 14 was good in both the sand laminating method and the hot laminating method. Only four cases of ratio 15, ratio 18, ratio 21, and ratio 22 failed. At the ratio of 15, the film thickness is thin and thus film melting and wrinkles are often observed. At the ratios of 18 and 22, there are many wrinkles due to a large heat shrinkage ratio of the film, and in the ratio of 21, the film has meandering and wrinkles due to uneven thickness of the film. It has been observed that the lami intensity is partially uneven.

Next, these laminated sheets are vacuum-formed by the above-mentioned method to obtain a molded article shown in FIG. 8 and its moldability (appropriate range, deep drawability, mold deciding property, uneven thickness of the molded product). , Film breakage, and temperature range (6 items) were evaluated. The evaluation results of the examples are shown in Experiment No. 11 of Table 11. 8 ~
No. 14 shows the evaluation results of the comparative example.
Ratios 12 to 22 are shown respectively.

Experiment No. 3 of the third embodiment. 8 to 14 are moldability (suitability range, deep drawability, mold determining property, uneven thickness of the molded product,
Film break, temperature range) and appearance of molded container (looks good)
In all of the items, excellent performance was exhibited evenly, but in Experiment No. 3 of Comparative Example 3. It can be seen that, in the ratios 12 to 22, even if there are seven excellent appearances (the appearance of the molding container), none of them pass the molding aptitude of the liver and kidney.
For example, in experiment no. The appearance of the container is good except for a film having a large rubber component such as the ratio 20 to 22 and a film having a relatively high haze of the ratio 16 but the ratio of the moldability is 12,
Since the film has a high apparent tensile elastic modulus, such as 13, 17, 19 and 20, the suitable range in molding, deep drawability, mold regularity and molding temperature range are poor, the same ratio 13, 17,
It can be seen that the film breakage of the molded product becomes conspicuous because the tensile elongation is extremely small as shown in No. 19. In addition, FIG.
Experiment No. of Example 3 Experiment No. 9 of Comparative Example 3 and Comparative Example 3.
As shown in the example of the wide range of the moldability range for the ratios 19 and 20, it is understood that the moldability of the example is remarkably excellent. As described above, the laminated sheet which is the aim of the present invention is indispensable to be comprehensively excellent in the three properties of laminating suitability, molding suitability, and appearance of the molded body, and from comparative examples outside the suitability requirements of the present invention, It can be seen that the desired laminated sheet and its molded body cannot be obtained.

[0073]

[Table 1]

[0074]

[Table 2]

[0075]

[Table 3]

[0076]

[Table 4]

[0077]

[Table 5]

[0078]

[Table 6]

[0079]

[Table 7]

[0080]

[Table 8]

[0081]

[Table 9]

[0082]

[Table 10]

[0083]

[Table 11]

[0084]

[Table 12]

[0085]

EFFECTS OF THE INVENTION The present invention, as clearly shown in the above examples, is a styrene resin film that has good compatibility with PSP, does not require separation and recycling, and has no deterioration in quality due to gels, etc. , Excellent in gloss and rigidity, PSP
The elongation at the molding temperature is large, and the apparent tensile elastic modulus at the temperature is small so that the film for printing that does not become the deformation resistance of the PSP at the time of molding is laminated. It is an excellent product useful for the industrial world, which can provide a laminated sheet having excellent moldability with excellent moldability and a molded product thereof.

[Brief description of the drawings]

FIG. 1 Cross-sectional view of a single-area layer of a polystyrene-based laminated sheet (thermal laminate)

FIG. 2 Cross-sectional view of a single-area layer of a polystyrene-based laminated sheet (extrusion sand laminate)

FIG. 3 is a stress-strain curve diagram for obtaining an apparent tensile elastic modulus.

FIG. 4 is a plan view of a mold for evaluating formability.

5 is a vertical cross-sectional view of a moldability evaluation mold (AA in FIG. 4).
line)

6 is a vertical cross-sectional view of a moldability evaluation mold (BB ′ in FIG. 4).
line)

FIG. 7 is a grid division diagram showing a molding suitability range.

FIG. 8 is a perspective view of a container molded with a mold for evaluating moldability.

FIG. 9 is a grid section diagram showing the molding suitability ranges of Example 3 and Comparative Example 3.

[Explanation of symbols]

 1 Polystyrene film 2 Printing layer 3 Expanded polystyrene sheet 4 Adhesive resin layer 5 Laminated sheet 6 Molding container 7 One section of a square section showing a range with good moldability

Claims (2)

[Claims] 1. A laminated sheet obtained by laminating a styrene film on at least one surface of an expanded polystyrene sheet, wherein the expanded polystyrene sheet has a thickness of 0.8-3.
5 mm, the styrene film is the following resin (A)
And at least 1 comprising a resin composition containing (B) as an essential component
A film stretched in the transverse direction has an apparent tensile elastic modulus of 0. 0 measured at a temperature of 120 ° C according to ASTM-D882.
05-1.00 kg / mm ² , tensile elongation is 100% or more, and tensile elastic modulus measured at a temperature of 23 ° C. is 230-2.
80 kg / mm ² and 80 in a hot air circulation oven
A styrene-based laminated sheet having a longitudinal and lateral thermal shrinkage of -5 to 5% when heated at 10 ° C. for 10 minutes and a thickness of 10 to 80 μm. (A) at least 1 selected from vinyl aromatic hydrocarbons
Styrene-based polymer 10-90 containing a seed monomer as a main component
% (B) Copolymer of vinyl aromatic hydrocarbon and aliphatic unsaturated carboxylic acid ester, copolymer containing 90 to 95% by weight of vinyl aromatic hydrocarbon, 90 to 10% by weight 2. A molded product comprising the styrene-based laminated sheet according to claim 1.