JPS62285928A - Laminable non-oriented sheet or film made of vinylidene chloride resin - Google Patents

Abstract

PURPOSE:To obtain the title sheet or film which is transparent and has a high barrier property and a possibility of widening the applicable range of deep drawing, by using a specified vinylidene chloride/methyl acrylate copolymer resin and specifying its plasticizer content, transparency, heat shrinkage and thickness. CONSTITUTION:A sheet or film which is a non-oriented sheet or film comprising a vinylidene chloride/methyl acrylate copolymer resin of a methyl methacrylate component content of 4-8wt%, wherein the liquid plasticizer remaining in this film layer is 4wt% or below, the transparency (HAZE value) is 10% or below, the heat shrinkage at 90 deg.C<=5%, and the thickness is in the range of 10-100mu. This sheet or film has a high barrier property and a possibility of widening the applicable range of deep drawing, which has not been attained by conventional commercially available films. In addition it is markedly improved in workability in film formation and is very useful in industry as a non-oriented vinylidene chloride resin film for molding.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Industrial Application Field] The present invention provides a matured form that can be laminated with other thermoformable resin sheets/films and has scum and water vapor barrier properties. This invention relates to a vinylidene chloride-based resin that serves as a barrier layer for laminated sheets and films for use in laminates, and an improvement technology for unstretched sheets and films for lamination.

(Conventional technology) Laminated sheet/film for thermoforming (hereinafter abbreviated as film)
A vinylidene chloride resin unstretched film for laminating with a single layer of burrs ψ is commercially available and known, for example, as "Unstretched 1 Nalan Film (trade name, manufactured by Fukaisei Co., Ltd.)".

This material is a vinyl chloride component or about 10% by weight of hnylidene chloride/vinyl chloride copolymer resin, and contains about 7% by weight of a liquid plasticizer as a modifier, so it has a thickness of 10% by weight.
Oxygen permeation G per micron is approximately 30CC'fff'';
Transparent (HAZE 3%) with fj gas burr V- properties
It is also known as unstretched film.

Moreover, this product can be produced by a manufacturing method as shown in FIG. 3 of the published specification of Canadian Patent No. 713,477.
A film that is stretched and coextruded with a vinylidene chloride resin layer sandwiched between two resin layers such as polyethylene, which do not bond well with vinylidene chloride resin, then cooled and rolled up, and then rolled up at a later date. A manufacturing method is used in which the film is peeled off into three pieces and a flat unstretched vinylidene chloride resin film is taken out.

The reason for this is that the resin, which is easily thermally decomposed and difficult to stretch, is made thinner without being decomposed by using the extrusion extensibility of other resins with less plasticizer, and by crystal assimilation. It is said that this method is designed to protect a thin layer that is soft and difficult to deform over time and harden it from external forces.In addition, this manufacturing method involves transferring the plasticizer in the vinylidene chloride resin layer to the outer layer and absorbing it. It is also known that there is an advantage of improving gas barrier properties by reducing the amount of plasticizer in the vinylidene chloride layer.

The unstretched film for lamination carefully made in this way is used as the core of the laminated film for molding.
With the help of advances in molding technology, it has come to be widely used in various molding fields.

[Problems to be Solved by the Invention] However, this unstretched film for lamination has the following three problems.

1 The level of gas barrier property is rather low, at least the thickness is 1
The oxygen permeability per 0 micron is required to be 10cc or less, but the current problem is that it stays around 30cc.In order to improve this gas barrier property, it is necessary to reduce the amount of liquid plasticizer added. However, there is a concept that compensates for the deficiency by adding plasticized resins (for example, "Unstretched 4 Naran Film" C3H1 (trade name, manufactured by Fukkasei Co., Ltd.)).
The film quality of these products becomes cloudy and opaque, and cannot be applied to this field.

? It is predicted that in the field of deep drawing, a forming defect phenomenon in which the vinylidene layer breaks will occur at the wall where the local drawing ratio becomes large, and that this phenomenon can be corrected by increasing the plasticity of the vinylidene layer. Although it is possible, this problem cannot be targeted because the barrier properties are already below the target level.

3 When trying to make a laminate, there are unstretched parts of the laminated resin on the non-stretched film, or uneven and wrinkled parts, which cannot be completely laminated, resulting in a defective product.

The cause of this is that the vinylidene chloride resin does not solidify properly during the production of the unstretched film (currently, it is peeled off after one week or more), and a defective phenomenon occurs during the peeling operation.

Therefore, an object of the present invention is to solve the above-mentioned problems, that is, to provide an unstretched vinylidene chloride resin film that can improve the above-mentioned problems.

(Means for solving the problem) To explain the essential requirements of the present invention according to its role 1, the main part for solving the problem is described in the claims. Vinylidene chloride methyl acrylate containing 4 to 8% by weight of methyl methacrylate component
Consists of copolymer 1 resin, residual content of liquid plasticizer is 4% by weight
It is in the section labeled "Unstretched Sheet/Film" below.

And following this, "Transparency (HAZE value) is 10% or less, heat shrinkage rate at 90℃ is 5% or less, wall thickness is 10μ
~100μ non-stretched sheet/film for laminating is a film that has been adjusted in the mounting process to a shrinkage rate that does not cause devitrification or whitening and is easy to laminate, and can be used in the field of lamination molding. It is clearly stated that the film was formed as a non-stretched film with the same thickness as possible. Therefore, this requirement is necessary to ensure the basic quality of the laminate molded product.

That is, for example, if the resulting unstretched film has a large IAZE value exceeding 10%, the obtained molded product will be opaque and not practical in this field, and it will not be suitable for heating at 90°C ( If the heat shrinkage rate exceeds 5%, the heat shrinkage force (○R3) will naturally be higher than 19 Ky/cm, so heating during lamination will easily cause interlayer displacement and defects.
If the thickness is less than 10 μm or more than 100 μm, it means that it is no longer suitable for the field of lamination molding.

The meaning of the above important requirements will be explained in detail below using drawings and the like.

FIG. 1 is an experimental diagram showing the dissipation rate of the plasticizer contained in the vinylidene chloride resin used in the present invention.

The horizontal axis is the plasticizer claw (% by weight) initially contained in the resin;
The vertical axis is the dissipation rate of the plasticizer sieved from the plasticizer 0 remaining in the final unstretched film.

The solid line indicates the case of the resin used in the present invention (methyl acrylate-1
~ component 5%), and the broken line shows the case of a conventional commercially available film resin (PVC component 10%).

In both cases, polyethylene resin is laminated on both sides of a vinylidene chloride layer, stretched in a die, extruded from a T-die into a plate shape so that the vinylidene chloride layer has a thickness of about 30μ, cooled, and wound up. After 3 days, the film was peeled off and taken out as a vinylidene chloride resin and unstretched film, which was then analyzed.

The results shown in FIG. 1 indicate that the vinylidene chloride resin used in the present invention has a larger loss/lose ratio of plasticizer during processing than conventional products. In addition, in the present invention, by utilizing this phenomenon tendency of the resin, the processing suitability of the resin, which tends to be unstable, is compensated for by adding as many plasticizers as possible during extrusion and film forming processing, and on the other hand, The amount of plasticizer is brought to such a level that it has excellent gas barrier properties and excellent moldability when taken out as an unstretched film. The completion of an invention lies in the investigation of such points of harmony.

FIG. 2 shows examples of molding defects that tend to occur in molding in this technical field, and the figures A), A), and C) show the magnitude of the defects in order.・ Figure 3 is an enlarged sketch (approximately 40 times) showing the causes of the black streaks on the molded container in A), A), and C) of Figure 2, and is a cut cross section of the container wall. It is shown that the vinylidene chloride resin layer in the laminated layer is broken.

The purpose of improving formability in deep drawing in the present invention is to eliminate such phenomena and expand the suitable temperature range for forming.

Figure 4 shows the analysis results.
), the horizontal axis indicates the amount of methyl acrylate-1 component (2% by weight) in the film resin layer.

In Figure 4, the points 7091 to 7091 correspond to the symbols in the overall evaluation section of Table 1, which summarizes the results of Examples and Comparative Examples, and the methyl acrylate component and residual plasticizer amount of the target film. This is an analytical diagram drawn with experiment N (l) at the related coordinates.The arrows indicate changes from the initial plasticizer added to the resin.The amount of methyl acrylate located in the middle is It is based on calculations from ratios.

According to the results shown in Figure 4, the level of gas barrier properties is maintained,
It also improves moldability, maintains the appearance quality of the finished molded product, improves workability during film formation, shortens holding time before peeling off, and eliminates film wrinkles and peeling defects, all of which contribute to high performance. Those that reach the standard have a methyl acrylate content of 4 to 8% by weight, a residual plasticizer content of 4% by weight or less, and have a long arrow length, i.e., those with a long arrow length, i.e., many plasticizers were first published at h0
It turns out that he was trying to avoid dissipating it later.

However, achieving the objective of the present invention, i.e., gas barrier
If it is guaranteed that methyl acrylate ■ is 4 to 8% by weight and the amount of residual plasticizer is 4% by weight or less in order to improve the level of properties, the improvement level of moldability, and poor film peeling. It has also been shown that this objective is achieved satisfactorily.

The present inventors have discovered that the following phenomena occur in the dissipation zone of plasticizer, which affects processability during film formation, elimination of film wrinkle defects that remain after peeling, and shortening of holding time until peeling. In other words, the excess plasticizer that first plasticized the resin and made it easier to stretch is extruded from the vinylidene 4 by the suction action of the adjacent resin as the resin crystallizes. However, since the adjacent resin cannot absorb the entire amount in a short time, it accumulates between the vinylidene layer and the adjacent resin.On the other hand, the vinylidene layer, which has undergone crystallization, is smeared due to the resin properties of the methyl acrylate component. It is speculated that the layer is stiff and resistant to deformation, and that it is extremely easy to peel off between the layers, resulting in a phenomenon where the layer can be completely peeled off along the lines between the layers.

The liquid plasticizer used in the present invention refers to a liquid plasticizer known as a plasticizer for vinyl chloride resin. Among these, liquid plasticizers are carefully selected from aliphatic dibasic acid ester-based, citric acid ester-based, fatty acid ester-based, polyester-based, etc. from the viewpoint of food safety and hygiene.

The qualitative and quantitative characteristics of plasticizers can be found in publications related to analysis, such as the "Polymer Analysis Handbook" (edited by the Japanese Society for Analytical Chemistry, 1985).
It can be carried out by a method using a gas chromatograph and a mass spectrometer using the solvent extraction method described in 2006).

The plasticizer dissipation rate is the ratio (wt%) of the amount of plasticizer (B) dissipated during the extrusion-laminated film forming and peeling process to the initial content ♀ (8), that is, the dissipation rate of the plasticizer. (1%) = -X100.

In addition, the thermoplastic resin used for the amphoteric side layer, which is peeled off after forming a three-layer structure with vinylidene chloride resin as the core layer, does not exhibit sufficient thermal adhesion to the vinylidene chloride resin, and the extrusion temperature is too high for chloride. There is no particular limitation as long as it does not accelerate thermal deterioration of the vinylidene resin, but it is preferable to use a polyolefin resin from the viewpoint of repeated reuse or the usability of the film after peeling off. More preferably, low density polyethylene is used.

The evaluation method and evaluation scale used in the present invention are shown below.

■] Suitability for film forming processing When forming a laminated film containing an unstretched vinylidene chloride resin film, the generation of bubbles due to carphone and thermal decomposition is observed with the naked eye, and the time required until generation is recognized is evaluated below. It was evaluated using a scale.

Evaluation symbol Evaluation scale ◎; 6 hours or more ○; 3 hours or more and less than 6 hours Δ; 1 hour or more and less than 3 hours The film was stored at 20°C and 10
0711111 width, 2Tr1. Cut into strips, 5T
The film was taken out at a peeling speed of rL/min, and the elapsed time required until the length of the taken out film was suppressed to an increase of 3% or less with respect to the discoloration in the laminated state was evaluated using the following evaluation scale.

Evaluation symbol Evaluation scale ◎; Less than 1 day ○; 1 day or more and less than 3 days △; 3 days or more and less than 7 days Then, it was brought into contact with a heated roll of diameter 250 mm heated to 120'C at a holding angle of 90°, and run at a speed of 6()TrLZ to check the occurrence of vertical wrinkles at the winding section and horizontal wrinkles at the edge section. It was inspected with the naked eye and the number of wrinkles per 100 m was evaluated using the following evaluation scale.

Evaluation symbol Evaluation scale ◎; No occurrence O; 1 to 2 occurrences △: 3 to 5 occurrences The vinylidene resin film was turned over for 100 m, during which time the surface of the film was observed with the naked eye, any peeling defects were measured, and the film was evaluated using the following evaluation scale.

Evaluation symbol Evaluation scale ◎; Absolutely no defects ○; 1 to 5 defects △; 6 to 10 defects The film is ASTHD-39851 and then HOCON 0XT
Oxygen gas permeability was measured using a RAN 100 model at 20'C and 65% RII, and evaluated using the following evaluation scale.

Evaluation symbol Evaluation scale (unit cc/74.day, atm) ◎: 6 or less ○: Over 6 and 10 or less △; Over 10 and 15 or less Unstretched polypropylene sheets (manufactured by Mitsui Toatsu Co., Ltd. > 5) are placed on both sides of the stretched vinylidene chloride resin film.
00μ and unstretched polypropylene film (manufactured by Tohcello Co., Ltd.)
50μ and 50 μm were laminated together using an adhesive to form a sheet with a total of three layers, plug-assist molding was performed using an Erich molding machine, and the following items were evaluated: ■Appearance quality ■Mold reproducibility ■Resistance to mold reversion.

The heating temperature of the sheet is determined by the discoloration of the heat label attached to the edge of the sheet, and the heating level is T150-160°.
C, I [165-175°C, 1180-190°C1
The drawing ratio (mold depth ÷ frontage diameter) level @ 0.3. II O,6,III O,9,IV
1.2. Five levels of V 1.5 were set.

(2) Appearance Quality The molded products, which were molded into container shapes by changing the heating temperature and drawing ratio, were visually observed from the bottom to evaluate the presence or absence of defects in appearance as illustrated in FIG. 2.

The breadth of the range of heating temperature and drawing ratio in which this defect does not occur was evaluated using the following evaluation scale.

Evaluation symbol: Evaluation scale Drawing ratio rank IV or higher ■ Mold reproducibility ■ Measure the degree of roundness of the bottom corners of a container-shaped molded product measured by 1q from the outside of the container with an R gauge, and the roundness of the corners of the molded product is 5 or less. The range of heating temperature and drawing ratio that resulted in the following evaluation was evaluated using the following evaluation scale.

Evaluation symbol Evaluation scale Heating rank level 3 or above Drawing ratio rank ■ Q ; Or Heating rank 2 level Drawing ratio rank IV or above Drawing ratio rank ■ Below ■ Resistance to molding ■ The bottom outer diameter of the molded product obtained. LJ that is measured and the value divided by the inner diameter of the mold is 0.95 or more
The breadth of the range of O heat humidity and aperture ratio was evaluated using the following evaluation scale.

Evaluation symbol: Evaluation scale heating rank is level 3 or higher and drawing ratio rank is IV or higher; Heating rank is level 3 or lower and drawing ratio rank is ■ Comprehensive evaluation of the above 8 evaluation items individually evaluatedflT
For combination I of the i symbol, emphasis was placed on -C, gas barrier properties, poor peeling, film wrinkles, moldability, and the product 1t, and the degree of sufficiency was evaluated using the following scale.

Evaluation scale　　　　　　　　　　　　　　　　rating symbol All items are ◎ or Q ◎ Number of O's is 2 or less All items are ◎ or ○.

Number of ○ is 3 or more Even one term must have Δ △ There is X even in term 1. The content of the present invention will be explained in detail in the following Examples and Comparative Examples.

The vinylidene chloride resin that is the base resin used for the evaluation of Examples and Comparative Examples is:
It is a copolymer resin of vinylidene chloride and methyl acrylate, and each component in the resin, vinylidene chloride to methyl acrylate, is adjusted to a range of 97:3 (wt%, the same hereinafter) to 91:1. can also be obtained, for example, by the method described in Japanese Patent Application No. 59-240483,
1.0% by weight of epoxidized linseed oil was added to the resin component in advance.

To the above base resin, diisobutyl adipate and tributyl acetyl citrate were added in advance at an Ifm ratio of 60:40.
A vinylidene chloride-based resin composition was prepared by adjusting the amount of liquid plasticizer mixed in (% by weight) to correspond to the starting point of the arrow in FIG.

These compositions were sequentially melt-extruded using an extruder with a diameter of 90 m and L/D: 24, while AS'rM D-12
Low-density polyethylene with a melt index of 2.5 measured at 190'C and 2.1 sKg VJ weight according to 38 was melt-extruded using an extruder with a diameter of 120 mm and L/D: 22, and both molten resins were extruded, for example. The vinylidene chloride resin was laminated into a three-layer structure with a core layer using a laminating device such as the Feed Port Block manufactured by Dow Chemical Company in the United States, and then rolled up as a three-layer film with a width of 1200 m using the usual T-DieCrest method. .

At the time of extrusion film formation, film forming processability was also evaluated using the evaluation method and evaluation scale described in the text.

The jqed laminated film is stored in a 20'C atmosphere,
The peeling retention time was evaluated using the evaluation method and evaluation scale described in the text, while keeping up with the passage of time based on the plasticizer dissipation rate data obtained in preliminary experiments.

An unstretched vinylidene chloride resin film having a width of m was taken out.

All unstretched films are transparent (ASTM
HAZE value measured with D-1003 7% or less > Indication of heat shrinkage g': A (AS'rM D-2732 equivalent 90°C
(7) shrinkage rate of 3% or less).

Poor peeling of these unstretched films, film wrinkles,
While the barrier property was evaluated according to the evaluation method and evaluation scale described in the text, the residual plasticizer in the portions where both surfaces of the film were wiped with ethyl alcohol was measured and is shown in Table 1 together with Experiment No.

Furthermore, regarding the moldability of the film, items such as appearance quality, mold reproducibility, and mold reversion resistance were evaluated in accordance with the evaluation method and evaluation scale described in the text from the viewpoint of a wide range of possible conditions.

Table 1 shows the above evaluation results along with the ratio of each component and residual plasticizer of the vinylidene chloride/methyl acrylate copolymer resin film.

It is difficult to understand useful factors from the evaluations in Table 1 alone, so
An analytical diagram illustrating the relationship between the content of Methyl Acrylate-1 and the amount of residual plasticizer is shown in FIG. 4.

From the results of this evaluation and analysis, methyl acrylate-1 to 4 components
If the amount is too small (less than 8% by weight), film forming processability, appearance quality of the molded product, and mold reproducibility are likely to be impaired;
It can be seen that if the amount exceeds the weight percentage, the peeling retention time, peeling failure, film wrinkles, and mold reproducibility become worse.

Furthermore, it can be seen that when the residual plasticizer content is too large, exceeding 4% by weight, not only does molding reversion become worse, but also the target barrier properties are likely to be impaired.

From the above, the content of the methyl acrylate component in the copolymer resin is in the range of 4 to 8% by weight, and the amount of residual plasticizer is 4% by weight.
It can be seen that high standards can be maintained in all evaluation items if the results are within the following ranges.

As is clear from the above, the embodiment of the present invention is based on the first evaluation experiment Nc5.6.7.10.11.14.16.17.18.
The comparative examples are the same actual risk NQ1, 2, 3, 4.8°9,
12.13.15.19.20.21.22.

(The following is a margin) (Effects of the Invention) By adopting the above-described configuration, the present invention can be applied to a commercially available film such as "Uncentrifuged Saran Film, JC2M.

C5H (product name, manufactured by Asahi Kasei Corporation) etc. could not be achieved.
Industrially used as an unstretched hnylidene chloride resin film for molding, which can be transparent, has high barrier properties, expands the range of suitability for deep drawing, and at the same time greatly improves workability in film forming processing. This is an extremely useful invention.

[Brief explanation of drawings]

FIG. 1 is an experimental diagram showing the dissipation rate of plasticizer. 2nd p1 is a perspective view of the molded product showing a state of defective molding. FIG. 3 is an enlarged cross-sectional view (approximately 40 times) of the defective portion shown in FIG. 2. Figure 4 is an analysis diagram of the experimental results. Patent applicant Asahi Kasei Kogyo Co., Ltd. Agent Patent attorney Kazuya Nozaki Figure 1 Plasticizer addition amount Weight % Figure 2 Figure 3 X: Propylene resin layer Y; Vinylidene chloride resin layer Z: Polypropylene resin layer 4 Figure Methyl acrylate component content - 11i% procedure manual (
Voluntary) November 6, 1986

Claims (1)

[Claims] In an unstretched film for lamination made of vinylidene chloride-based resin, the methyl methacrylate component is made of a vinylidene chloride/methyl acrylate copolymer resin of 4 to 8% by weight, and the liquid plasticizer remaining in the film layer is 4% by weight or less. , transparency (HAZE value) is 10% or less, heat shrinkage rate at 90°C is 5% or less, wall thickness is 10μ to 100μ
An unstretched sheet/film for lamination made of a vinylidene chloride resin, characterized in that it is within the range of .