JP2009066915A - Multilayer film or sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer film or sheet having a low environment load, an excellent dimensional stability, and an excellent durability under a high-temperature and high-humidity environment. <P>SOLUTION: The multilayer film or sheet is formed by laminating a plant-derived resin layer (I) (a polylactic acid, nylon-11, or thermoplastic starch), and a rubber reinforcing styrene resin layer (II) (the rubber reinforcing styrene resin independently, or an alloy composed by mixing the rubber reinforcing styrene resin and at least one kind selected from a styrene copolymer resin, a polycarbonate resin, and a polymethyl methacrylate resin). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multilayer film or sheet formed by laminating a plant-derived resin layer (I) and a rubber-reinforced styrene resin layer (II). Specifically, the present invention relates to a multilayer film or sheet having a low environmental load, excellent dimensional stability, and excellent durability under a high temperature and high humidity environment.

In recent years, environmental issues on a global scale include depletion of petroleum resources due to increased use of petrochemical products, global warming that is thought to be due to the increase in carbon dioxide in the atmosphere due to incineration of household garbage and waste plastics, etc. Its seriousness is increasing. In response to these global problems, for example, film or sheet products using polylactic acid are actively developed. Polylactic acid is a resin made of lactic acid obtained from plant corn and moss as a raw material, and is known as an environmentally friendly resin that does not use petroleum as a raw material while having biodegradability. However, polylactic acid alone has a practical disadvantage such as its durability to withstand long-term use, especially in a high-temperature and high-humidity environment, due to its biodegradability, and inferior impact resistance and heat resistance. For this reason, Patent Document 1 (Japanese Patent Laid-Open No. 2006-328368) proposes improving the impact resistance of a film or sheet product by blending polylactic acid resin with polylactic acid. However, concerns remain about the low heat resistance derived from polylactic acid and the durability due to hydrolysis in a high humidity environment, and further improvements are desired.
JP 2006-328368 A

  An object of the present invention is to provide a multilayer film or sheet having a low environmental load, excellent dimensional stability, and excellent durability under a high temperature and high humidity environment.

As a result of intensive studies in view of such problems, the present inventors achieve the above object by forming a multilayer film or sheet obtained by laminating a plant-derived resin, a rubber-reinforced styrene resin, and respective resin layers. It has been found that the present invention has been reached.
That is, the present invention provides a multilayer film or sheet obtained by laminating a plant-derived resin layer (I) and a rubber-reinforced styrene resin layer (II).

  The multilayer film or sheet obtained in the present invention has a low environmental load, excellent dimensional stability, and excellent durability under high temperature and high humidity environment, so existing biaxially stretched polyester, acrylic sheet, etc. It can be practically used as a film or sheet instead of petroleum-based materials, and can greatly expand the range of use of plant-derived materials such as polylactic acid.

Hereinafter, the present invention will be described in detail.
The multilayer film or sheet in the present invention is obtained by laminating a plant-derived resin layer (I) and a rubber-reinforced styrene resin layer (II).

  The plant-derived resin constituting the plant-derived resin layer (I) in the present invention includes polylactic acid, nylon-11, nylon-6.10, thermoplastic starch, polybutylene succinate, polybutylene succinate adipate, polybutylene. Polyalkylene succinates such as succinate terephthalate, polyethylene succinate, and polybutylene succinate carbonate, polyglycolic acid, polycaprolactone, polyhydroxybutyric acid, polyhydroxyvaleric acid, hydroxybutyric acid, hydroxyvaleric acid copolymer, etc. Can be mentioned. Of these, polylactic acid, thermoplastic starch, polybutylene succinate, polybutylene succinate adipate, polybutylene succinate terephthalate, and polyethylene succinate are preferred. Examples of these plant-derived resins that are commercially available include, for example, Mitsui Chemicals, Inc., trade name: Lacia, Unitika Ltd., trade name: Terramac, Showa High Polymer Co., Ltd., trade name: Bionore, BASF, Inc. : Ecoflex, DuPont brand name Biomax, Nippon Shokubai Co., Ltd. Brand name: Lunare, Mitsubishi Gas Chemical Co., Ltd. Brand name: Upek, Arkema Co., Ltd. Brand name: Rilsan B, etc. Of these, polylactic acid, nylon-11, and thermoplastic starch are particularly preferred.

The rubber reinforced styrene resin constituting the rubber reinforced styrene resin layer (II) in the present invention is a styrene monomer or a styrene monomer and a vinyl cyanide monomer in the presence of a rubbery polymer. And a resin obtained by copolymerizing one or more of other copolymerizable monomers as required.
The rubbery polymer that can constitute the rubber-reinforced styrene resin includes polybutadiene, polyisoprene, butadiene-styrene copolymer, isoprene-styrene copolymer, butadiene-acrylonitrile copolymer, butadiene-isoprene-styrene copolymer. Polymers, diene rubbers such as polychloroprene, ethylene-propylene copolymers, ethylene-propylene-nonconjugated diene copolymers, ethylene-butene-1-nonconjugated diene copolymers, or acrylics such as polybutyl acrylate Examples thereof include rubbers, polyorganosiloxane rubbers, and composite rubbers composed of two or more kinds of these rubbers. One or two or more kinds can be used. Of these, diene rubber and acrylic rubber are particularly preferable.
Examples of the styrenic monomer include styrene, α-methylstyrene, paramethylstyrene, bromostyrene, and the like, and one or more of them can be used. In particular, styrene and α-methylstyrene are preferable.
Examples of the vinyl cyanide monomer include acrylonitrile and methacrylonitrile, and one or more of them can be used. Particularly preferred is acrylonitrile. Other copolymerizable monomers that can be used with styrene monomers and vinyl cyanide monomers include (meth) acrylic acid ester monomers such as methyl methacrylate and methyl acrylate. , Maleic anhydride, unsaturated acid monomers such as dimethyl maleate, and maleimide monomers such as N-phenylmaleimide and N-cyclohexylmaleimide, which are used singly or in combination. Can do.
The composition ratio of the rubber-like polymer constituting the rubber-reinforced styrene resin and the total monomer (styrene monomer, vinyl cyanide monomer and other copolymerizable monomers) is particularly limited However, from the viewpoint of the balance between the processability and physical properties of the resin composition, particularly the impact resistance, the rubber-like polymer is preferably 5 to 70% by weight and the total monomer is 95 to 30% by weight.
The rubber-reinforced styrene-based resin in the present invention can be obtained by a known emulsion polymerization method, suspension polymerization method, solution polymerization method, bulk polymerization method, or any combination thereof.

In the present invention, as the rubber-reinforced styrene resin layer (II), the rubber-reinforced styrene resin alone, or the rubber-reinforced styrene resin and styrene copolymer resin, polylactic acid, nylon-11, thermoplastic starch, polymethyl It is possible to mix at least one selected from methacrylate resin, polyamide resin, polycarbonate resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyphenylene ether resin, polyvinyl chloride resin, polysulfone resin, polyarylate resin, It is preferable to use one or more thermoplastic resins selected from styrene copolymer resins, polycarbonate resins, and polymethyl methacrylate resins. Of these, the styrene copolymer resin can be used for the purpose of adjusting the content concentration of the rubber-like polymer in the rubber-reinforced styrene resin. It is obtained by copolymerizing a monomer based on a vinyl cyanide monomer and, if necessary, one or more other copolymerizable monomers.
Moreover, what is generally marketed can be used as polycarbonate resin, polymethylmethacrylate resin, and other thermoplastic resins.

  Examples of the method of mixing the rubber-reinforced styrene resin and the other thermoplastic resin as the rubber-reinforced styrene resin layer (II) in the present invention include a method using a known kneader such as a Banbury mixer or an extruder. Also, there is no restriction on the mixing order, and the two components are mixed together. Furthermore, in the case of three components, not only the three components are mixed together, but also the remaining one component is mixed in advance. Is also possible.

  The multilayer film or sheet in the present invention is one in which the plant-derived resin layer (I) and the rubber-reinforced styrene-based resin layer (II) are laminated. The resin layer (I) is 0.001 to 2 mm and the rubber-reinforced styrene resin layer (II) is 0.001 to 2 mm. Moreover, there is no restriction | limiting in particular in the lamination | stacking leaf number and lamination | stacking order of each of said plant origin resin layer (I) and rubber reinforcement styrene resin layer (II), and especially rubber reinforcement styrene resin layer (II) is a single layer. Alternatively, two or more layers may be stacked. In particular, a multilayer film or sheet obtained by laminating the rubber-reinforced styrene resin layer (II) on both outer layers of the plant-derived resin layer (I) is most preferable from the viewpoint of practicality.

  Furthermore, the plant-derived resin layer (I) and / or rubber-reinforced styrene-based resin layer (II) constituting the multilayer film or sheet of the present invention may be mixed with a resin depending on the purpose as long as the physical properties are not impaired. Stabilizer, UV absorber, lubricant, mold release agent, plasticizer, antistatic agent, flame retardant, pigment, dye, reinforcing agent (talc, mica, clay, glass fiber, etc.), colorant ( Known additives such as carbon black, titanium oxide, etc., inorganic fine particles (titanium oxide, silica, barium sulfate, calcium carbonate, etc.), and organic crosslinked fine particles (methacrylic resin, silicon resin, etc.) can be used. Although there is no restriction | limiting in particular in the shaping | molding temperature at the time of shape | molding the multilayer film or sheet | seat of this invention, It is preferable that it is 160-250 degreeC.

The method for forming the multilayer film or sheet of the present invention is not particularly limited. For example, molding using a multilayer extruder such as a multilayer sheet extruder or a multilayer inflation molding machine, or individual roll molding, calendar molding, or sheet molding. It is possible to mold each film or sheet molded by inflation molding by bonding with an adhesive or a hot press method. Furthermore, the multilayer film or sheet of the present invention may be stretched by a known uniaxial or biaxial stretching method even in an unstretched state.
The multilayer film or sheet thus prepared can be used for thick materials such as trays and blister packs in addition to packaging films such as shrink films and agricultural material films. Furthermore, by using an insert molding method or an in-mold molding method using an injection molding machine or a press molding machine, it can also be used as a base film to be bonded to the surface of a thermoplastic resin such as ABS resin or polyolefin resin. is there.

〔Example〕
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not restrict | limited at all by these.

-Plant-derived resin layer (I)-
a-1: Polylactic acid resin (LACEA H-400, manufactured by Mitsui Chemicals, Inc.)
a-2: Nylon-11 (Rilsan B BESN O manufactured by Arkema Co., Ltd.)
a-3: Thermoplastic starch (Golden Starch manufactured by E-Lab)

-Rubber reinforced styrene resin layer (II)-
Rubber reinforced styrene resin b-1-1: 50 parts by weight of polybutadiene latex (weight average particle diameter 0.3 μm, gel content 85%), 150 parts by weight of water, ethylenediaminetetraacetic acid disodium salt in a nitrogen-substituted polymerization reaction vessel 0.1 part by weight, ferric sulfate 0.001 part by weight, sodium formaldehyde sulfoxylate 0.3 part by weight, heated to 60 ° C., 14 parts by weight acrylonitrile, 41 parts by weight styrene and cumene hydroperoxide 0 A mixture consisting of 2 parts by weight was continuously added over 3 hours and further polymerized at 60 ° C. for 2 hours to obtain a graft copolymer latex. Thereafter, 100 parts by weight (solid content) of the latex was salted out using 0.5 parts by weight of sulfuric acid and 1.5 parts by weight of magnesium sulfate as a salting-out agent, and then 1.5% of rubber-reinforced styrene resin particles. Double volume of water was added, stirred, dehydrated and washed, and then dried to obtain a rubber-reinforced styrene resin (b-1-1).
b-1-2: Plug flow tower type reactor having a volume of 15 liters (described in “New Polymer Production Process (Industry Research Committee, Koji Saeki / Shinzo Omi), page 185, FIG. 7.5 (b)”) Using a continuous polymerization apparatus in which one 10-liter complete mixing tank is connected in series to a reaction tank of the same type as the Mitsui Toatsu type, showing C1 / C0 = 0.955 divided into 10 stages. A rubber-reinforced styrene resin was produced. 50.8 parts by weight of styrene, 16.9 parts by weight of acrylonitrile, 22.4 parts by weight of ethylbenzene, 9.9 parts by weight of Nipol NS310S manufactured by Zeon, 0.38 parts by weight of t-dodecyl mercaptan, 1,1-bis (t -Butylperoxy) A raw material comprising 0.045 parts by weight of 3,3,5-trimethylcyclohexane was continuously supplied to the continuous polymerization apparatus to polymerize the monomer. The first plug flow tower reaction vessel was set to 95 ° C., and the second complete mixing vessel was set to 120 ° C. After supplying the polymerization solution from the second reaction tank to a devolatilizing apparatus comprising a preheater (180 to 270 ° C.) and a decompression chamber (5 kPaabs), the rubber reinforced styrene resin (b-1-2) is passed through an extruder. Got.
Other thermoplastic resin b-2-1: Polymethyl methacrylate resin (Sumitex EX, manufactured by Sumitomo Chemical Co., Ltd.)
b-2-2: 120 parts of pure water and 0.3 part of potassium persulfate were charged in a pressure vessel, and then heated to 65 ° C. with stirring. Thereafter, a mixed monomer solution composed of 67 parts of styrene, 30 parts of acrylonitrile, 3 parts of methacrylic acid and 1.5 parts of t-dodecyl mercaptan and 30 parts of an emulsifier aqueous solution containing 2 parts of sodium dodecylbenzenesulfonate were continuously added for 5 hours. After that, the polymerization system was heated to 70 ° C. and aged for 3 hours to complete the polymerization. Thereafter, salting out, dehydration and drying were performed using calcium chloride to obtain an unsaturated carboxylic acid-modified copolymer b-2-2. The reduced viscosity of the obtained copolymer b-2-2 was 0.3.
b-2-3: Carboxyl group-containing olefin copolymer (Bondyne AX-8390, manufactured by Sumitomo Chemical Co., Ltd.)

  Each component for the rubber-reinforced styrene resin layer (II) is melt-kneaded with the composition shown in Table 1, and the resin composition for rubber-reinforced styrene resin layer (II) (c-1 to c-) shown in Table 1 The pellet of 7) was obtained.

[Examples 1 to 5]
Creation of multilayer film or sheet: Using the plant-derived resin layer (I) and the resin composition for rubber-reinforced styrene-based resin layer (II) shown in Table 1, the cylinder temperature is set to 210 ° C. in the combinations shown in Table 2. Then, using a 65 mm multilayer extruder, a two-layer unstretched film having a plant-derived resin layer (I): rubber-reinforced styrene resin layer (II) = 1: 3 and a thickness of 0.1 mm was prepared.
[Examples 6 and 7]
In the combinations shown in Table 2, plant-derived resin layer (I): rubber-reinforced styrene-based resin layer (II): rubber-reinforced styrene-based resin layer (II) = 1: 3: 1, thickness of 0.1 mm A three-layer unstretched film was prepared in the same manner as described above except that.
[Examples 8 to 10]
In the combinations shown in Table 2, rubber-reinforced styrene resin layer (II): plant-derived resin layer (I): rubber-reinforced styrene resin layer (II) = 1: 3: 1, thickness of 0.1 mm A three-layer unstretched film was prepared in the same manner as described above except that.
[Comparative Examples 1-3] A single-layer unstretched film having a thickness of 0.1 mm was prepared in the same manner as described above except that the plant-derived resin layer (I) was a single layer.
These evaluation results are shown in Table 2. The evaluation method is as follows.

Adhesiveness : A cross-cut test was performed on the outer layer (first layer described in Table 2) of the prepared film or sheet according to JIS K5400, and the following evaluation was performed according to the number of peeled cells.
○: Less than 5 squares peeled ×: 5 or more squares peeled
Dimensional stability : The prepared film or sheet is cut into 150 mm x 90 mm and left in a constant temperature room at 23 ° C and 50% relative humidity for 24 hours, and the length of the long side (150 mm direction) is L0. When the length of the long side after standing for 200 hours under the conditions of 40 ° C. and 90% relative humidity is L1, the evaluation is performed according to the value represented by the following formula.
(L1-L0) / L0 × 100 (%)
◎: Less than 0.5% ○: 0.5% or more, less than 1% ×: 1% or more
Humidity and heat resistance : The prepared film or sheet was left in a constant temperature and humidity chamber of 65 ° C. and 95% relative humidity for 200 hours, and then the film or sheet was bent 180 ° and the durability was observed.
○: Not broken ×: Cracked

  The multilayer film or sheet in the present invention is practically used as a film or sheet substitute for existing petroleum-based materials because it has low environmental impact, excellent dimensional stability, and excellent durability under high-temperature and high-humidity environments. It is possible and is very useful for the development of various environmentally friendly film or sheet products.

Claims (4)

A multilayer film or sheet obtained by laminating a plant-derived resin layer (I) and a rubber-reinforced styrene-based resin layer (II). 2. The multilayer film or sheet according to claim 1, wherein the plant-derived resin layer (I) is selected from polylactic acid, nylon-11, and thermoplastic starch. The rubber-reinforced styrene resin layer (II) is a rubber-reinforced styrene resin alone, or a rubber-reinforced styrene resin and a styrene copolymer resin, polylactic acid, nylon-11, thermoplastic starch, polymethyl methacrylate resin, polyamide resin. 2. A multilayer film according to claim 1, which is an alloy formed by mixing at least one selected from polycarbonate resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyphenylene ether resin, polyvinyl chloride resin, polysulfone resin, and polyarylate resin. Or sheet. The multilayer film or sheet according to any one of claims 1 to 3, wherein a rubber-reinforced styrene resin layer (II) is laminated on both outer layers of the plant-derived resin layer (I).