JPS58128817A - Manufacturing of modified film - 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 method for producing a modified film.

Conventionally, there are two methods for surface modification of films: for example, improving the surface tension by corona discharge treatment and sputtering treatment on the film surface, which are carried out to increase the printability of the film surface.

Alternatively, coating type droplets such as alanine-type amphoteric surfactants are used for the purpose of imparting antifogging properties to films, and ionic surfactants are used for the purpose of imparting surface conductivity. A common surface modification method involves dissolving the film in a solvent and then applying it to the film surface using a coating device such as a gravure roll. However, discharge treatment,
Methods such as sputtering can improve the surface tension by removing inert substances from the film surface and forming irregularities2. It is extremely difficult to simultaneously impart mechanical strength through this treatment, and in fact, the heat generated during the treatment often requires the film to be heat resistant. Furthermore, even when surface modification is performed by applying a drug, it is inevitable that the drug will fall off over time, making it difficult to maintain physical properties over a long period of time.

Furthermore, it is actually difficult to simultaneously require heat resistance, heat-sealability, mechanical strength, gas barrier properties, printability, etc. in a single film; The only option was to bond films with different functionalities together, or to extrude thermoplastic resins with nine different functionalities using a melt coextrusion method to create a multilayer structure.

By the way, if low molecular weight substances are arranged or mixed in the molten thermoplastic resin, when the thermoplastic resin begins to cool and solidify, the low molecular weight substances cannot be incorporated into the crystal lattice of the thermoplastic resin.

The surface layer that collects on the surface layer is amorphous or has a structure similar to that of a liquid.When the surface layer degree reaches a supersaturated state11, a film having a certain thickness is formed thereafter. The formation of this film can be achieved by selecting the affinity between the low molecular weight substance and the thermoplastic resin, cooling and solidification speeds, and the blending amount.
The degree of this will vary. The present invention has been made by focusing on this IIIK, that is, a thermoplastic resin (B) prepared by mixing and dispersing a radiation-polymerizable or crosslinkable low molecular weight organic compound is extruded into a film ( Q
After forming the film, the film (Q) is solidified by cooling.

This is a method for producing a modified film, characterized in that organic compound (4) K deposited in the form of a film on its surface is polymerized or crosslinked by irradiation with an electron beam. Note that the radiation referred to in the present invention is an electron beam or an α-ray.

I line means rla etc.

The low molecular weight organic compound (4) in the present invention includes:

The average molecular weight is 500 to 9. 1.2 = OOO range
Polybutadiene or 1,4-polybutadiene and acrylic graft modified products thereof.

Ester modified products, isocyanate modified products, and diene oligomers such as butadiene-styrene copolymers having an average molecular weight in the range of 1,500 to 7,000.

Moreover, K is an unsaturated polybasic acid such as maleic anhydride, a saturated polybasic acid such as 7-talic acids, and a varnish dithylated polycondensate of polyhydric alcohol, and the average molecular weight is from 1,000 to aoo.

and polyisocyanate oligomers such as polymerized polyisocyanates and polyincyanate adducts with average molecular weights from aooo to 10.
Polycondensation double addition oligomers such as solid polyamide oligomers with an amine value of 100 V or less and an average molecular weight of 700 to 000, and liquid polyamide oligomers with an amine value of 100 to 50 V), and Polystyrene oligomers having an average molecular weight of 700 to 0.000 and mixtures thereof can be used. Examples of the thermoplastic resin (2) include medium/low density polyethylene/, high density polyethylene/, polypropylene, ethylene-vinyl acetate copolymer resin, ethylene/-propylene/copolymer rubber, and ethylene/-propylene non-conjugated copolymer rubber.

Polyesters such as polyethylene terephthalate, 6
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Copolymerized nylons, ionomers, polystyrene fibers, and mixtures thereof can also be used.

First, when the low molecular weight organic compound (4) is solid.

This and the thermoplastic phase! 1101) is directly blended and charged into hopper +11 of a melt extruder as shown in FIG. The charged mixed resin is extruded into a film from the T-die (7) through the adapter (6) by the screw (2) K, and then passed through the cooling roll (8) and several cooling rolls (9) whose surface temperatures are adjusted. ) to cool at a constant cooling rate. In addition, when the low molecular weight organic compound (4) is liquid or viscous, K as shown in FIG.

After the thermoplastic resin 0) introduced from the hopper (1) is plasticized, it is blended from the hopper (3) through the vent hole (5) using a forced conveyance device such as a gear pump (4). After that, the process was carried out in the same manner as shown in Fig. 1.The cooling roll (9) whose surface temperature was adjusted was used to adjust the cooling rate of the extruded film. Adjustment of chemical degree and precipitated organic compounds (
4) Adjust the thickness of the film.

The thickness of the extruded film aQ may be in the range of 30p to 2000μ, but preferably in the range of 40* to 700−.

After the film is formed, it is irradiated with electron beam radiation, and the low molecular weight organic compound (4) deposited on the film surface is crosslinked and polymerized to form a hardened film. The dose of electron beam is 5 Mrad to 30 Mrad.
Any amount is acceptable, but it is preferably from 7 Mrad to 20 Mrad due to the need to prevent deterioration of the thermoplastic resin (B). In addition, the thickness of the polymerized organic compound (4) is determined by the cooling rate of the fillet trout extruded from the extruder as described above,
For example, it can be made into a thin film with a thickness of 1 OP or less. Figure 3 shows the cross section of the initial αQ of the obtained film, in which a polymerized organic compound (4
) films (b) and (b) exist. This skin H(ro)(
2) is one that has penetrated into the resin (B), and the organic compound (4) has a concentration gradient such that the concentration is highest at the surface of the film (C) 011 and the concentration decreases toward the inside. It is.

Figure 4 shows a three-layer coextrusion device.

For example, thermoplastic resin (2) can be coextruded with other resins to form an intermediate layer. The film obtained in this way is a three-layer film made of a thermoplastic resin containing a low molecular weight organic compound (4) (with Q as an intermediate layer), and as this film is cooled and solidified, the film (C) The low-molecular organic compound (4) precipitates at the interface between the (intermediate layer) and other layers, increasing its concentration, and the film (C
), the concentration of organic compounds decreases in the center. The film thus obtained is as shown in FIG. 5, in which a film (b) (2) of an organic compound (4) is laminated on the surface of the film (0 (intermediate layer) (2)).

Furthermore, another resin layer o4(2) is laminated on the outside thereof. Therefore, by selecting the organic compound (4) and the resin to be laminated, it is possible to obtain a laminate in which the two are firmly adhered, and it is also possible to obtain a laminate film with good peelability.

In addition, using the three-layer coextrusion apparatus shown in Figure 4, for example, a polyester oligomer as a low molecular weight organic compound (4) for obtaining heat resistance is blended into the surface layer (B) or (2) to impart rigidity. The rounded styrene oligomer is used as the middle layer (
By blending in 2), a laminated film having the characteristics of both K and 1 can be obtained.

The present invention has the above-mentioned configuration, and the film 1
When the low molecular weight organic compound (4) that contributes to modification forms a concentration gradient in the thermoplastic resin layer with a high concentration on the surface and a low concentration in the center, it is crosslinked and cured by K. The subsequent film layer has extremely strong adhesion to the thermoplastic resin, and its retention effect is greater than that of a chemical coating method or a lamination method using an adhesive.

Examples will be described below.

[Example 1] #l! Figure 4 shows nine T die three layers black, box L
The first layer is made of low-density polyethylene/((
Mitsui Polychemical ■Miraso/401 Density 0.920
) 35 weight, ethylene-propylene copolymer rubber (Mitsubishi Yuka EP-02PX density 0.86) 55 weight - 1 Low molecular weight organic compound (4) unsaturated polyester oligomer (Dainippon I/K Chemical Industry Poly 2ite 1PH-1
23N) 7.5% by weight and adipic acid polyester plasticizer (Dainippon Ia'F Chemical Industry ■Bolinizer W
-1000 average molecular weight 1000) 2.4 weight -2 anhydrous! It was extruded so as to have a blending composition of 0.1 weight of leic acid. The unsaturated polyester was forcibly conveyed through the first vent hole of the first extruder, and the mixture of plasticizer and maleic anhydride was forcibly conveyed through the second vent hole using a gas pump. The second layer contains the second
Using an extruder, high-pressure polyethylene/(Mirason 401) 35% by weight was used as a thermoplastic resin, 60% by weight of ethylene-propylene copolymer rubber (EP-02PX), and low molecular weight polystyrene (Sanyo Kamori Kogyo ■) was used as an oligomer.
・Imer 5T-75 average molecular weight 800) 4.8 weight-2
Liquid Polype/Tadiene (Nippon Bio/■ Quintol
A-500 was extruded to have an average molecular weight of 500) and a blending composition of 0.2 weight. The mixture of low molecular weight polystyrene and liquid polypentadiene was forcibly conveyed through the pit of the second extrusion trench using a vacuum pump. The third layer contains the third
Low density polyethylene (Miraso/401
) was extruded. The extrusion temperature was 230℃, and the film formation rate was 15
The film was formed using rv'wr, and the total thickness of the film was 20 pcm for the first layer, 20 pcm for the second layer, and 20 pcm for the third layer, and the surface temperature of the sheet cooling roll was 150 pcm.
While adjusting the temperature to ~70°C, the melt-formed film is gradually cooled to form a film in which oligomers are blended and dispersed.
Obtained. Furthermore, 2 layers were added from the first layer side of the obtained three-layer film.
A 5 Mrad electron beam was used with Otto-Dur's NP-ES.
It was irradiated using a H-150-020 scanning type electron beam irradiation device to obtain a modified nine film having the physical properties shown in Table 1-1. The modified film compared to the comparative example film.

Both surface hardness and mechanical strength were improved.

Table-1 Note 1) Low density polyethylene/film 60p is i-run y
401 (three-piece polychemical ■) by T-die method to 60
A comparative example was prepared by forming a film to the same thickness as the voice.

[Example 2] Polypropylene (Mikata Petrochemical Industry ■F-631) was produced as a thermoplastic resin using a single-layer T-die melt extrusion device.
30% by weight, and 61% by weight of ethylene-propylene/copolymer rubber (Mitsubishi Yuka EP-02P).

Adipic acid polyester (Dainippon Ink & Chemicals Polycizer W) is used as a siligomer through the extruder vent hole.
-4000 average molecular weight 4000) and liquid polyamide (Dainippon Ink & Chemicals ■Epiclo/1050)
) and 0.3% by weight of maleic anhydride were mixed and dispersed by forcibly conveying with a gear pump, and the processing temperature was 21%.
A film having a thickness of 60p was formed at 0° C. and gradually cooled to obtain a film having an oligomer coating on the surface.

Furthermore, one side of the obtained film was treated with a stain beam of 10 Mr.
A film having the physical properties shown in Table 2-2 was obtained by irradiating the film in the range from ad to 3° Mrad.

cram school Table-2

[Brief explanation of drawings]

The drawings show embodiments of the present invention, FIG. 1 and FIG. 2. FIG. 4 is an explanatory diagram of a dithering extrusion device. 3 and 5 are cross-sectional views of the extruded film. (1)...Hopper (2)...Screw (3)...Hopper +4+...Gear pump (5)
...Vent hole (6)...Adapter ())...
・T-die (8)...Cooling roll (9)...
・Roll A1 that requires cooling and whose surface temperature is adjusted...Film
α111Q! 1...Organic compound (4) (to)
・Thermoplastic resin (B)

Claims (1)

[Claims] (!) After a thermoplastic resin (B) obtained by mixing and dispersing a radiation-polymerizable or crosslinkable low molecular weight organic compound (4) is extruded by melt extrusion to form a film C). A method for producing a modified film, characterized in that the film (an organic compound cA that precipitates in the form of a film on the surface of the film as it cools and solidifies) is polymerized or crosslinked by irradiation with K radiation. (2) Co-extrusion of thermoplastic resin (B) and other resins. 12. The manufacturing method according to item 11 above, characterized in that the film (Q) is formed in a state where it is laminated with another film.