JP2001347570A - Manufacturing method for multilayer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a multilayer film by heating a plastic material being easy to mold and absorbing a microwave, by the microwave generated by a microwave oven. SOLUTION: The multilayer film is manufactured out of an aliphatic polyester absorbing the microwave, heating and being melted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a multilayer film using an aliphatic polyester resin.

[0002] The aliphatic polyester resin according to the present invention comprises
Excellent in fluidity and injection moldability, suitable for obtaining molded products such as films, sheets, filaments or fibers.The obtained molded products have sufficient mechanical strength, and absorb microwaves and absorb In many cases, heat is generated and melted, so that various industrial applications are possible. For example, it can be used for heat storage materials used after heating by microwave irradiation, production of multilayer films, heat sealing, bonding, and the like.

[0003]

2. Description of the Related Art Conventionally, in the case of bonding of different and / or the same kind of polymers, bonding is performed by using an adhesive or bonding by heating and melting.

For example, when manufacturing a multilayer film,
It has been necessary to combine a plurality of extruders and bond them in a molten state immediately after the extruders are formed in a die or immediately after the films are formed, or to apply an adhesive and then bond the films individually. However, in the above-mentioned production method, a complicated and large-scale apparatus was required, and the thickness accuracy of the bonded portion was not sufficient.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a microwave-absorbing plastic material which is easy to mold and process by microwave heating with a microwave oven or the like to obtain a multi-layer made of different and / or similar resins. It is to provide a method for manufacturing a film.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that an aliphatic polyester resin that absorbs microwaves from a microwave oven, generates heat, and melts is used. The present invention has been reached.

That is, according to the present invention, a laminating step of laminating a polymer film in contact with at least one surface of an aliphatic polyester resin film is performed, and then a heat treatment step of heating the aliphatic polyester resin film by microwave irradiation to perform laminating and bonding. And a method for producing a multilayer film.

The aliphatic polyester used in the present invention is a polycaprolactone resin or an aliphatic polyester resin containing glycol and an aliphatic dibasic acid as main components.

The process for producing an aliphatic polyester resin comprising a glycol and an aliphatic dibasic acid according to the present invention comprises a first step of polycondensing a glycol and an aliphatic dibasic acid to form an aliphatic polyester oligomer, and if necessary, It comprises a second step of reacting the aliphatic polyester oligomer with the dicarbonate. The first step of the present invention can be carried out by a batch system or a flow system. Here, the batch system will be described.

The first step is a step in which a glycol and an aliphatic dibasic acid are subjected to polycondensation in the presence of a transesterification catalyst to remove water or alcohol by-produced during the reaction and excess glycol. Reaction temperature 100-280 ° C
And finally under reduced pressure. As the pressure, a pressure at which the above-mentioned object is achieved is selected.
The pressure is preferably reduced to not more than mmHg. In this step, different types of glycols, dicarboxylic acid compounds and hydroxycarboxylic acid compounds can be added and copolymerized.

The molecular weight of the aliphatic polyester oligomer,
The acid value and the residual amount of the dihydroxy compound can be controlled by appropriately balancing the distillation rate of the unreacted dihydroxy compound and the reaction rate, and the conditions of the charged molar ratio, the catalyst, the temperature, the degree of reduced pressure, and the reaction time are adjusted. A method of appropriately selecting and combining and a method of blowing an inert gas at an appropriate flow rate are also realistic. Usually, the reaction temperature is 100 to 28 in the presence of a catalyst.
It can be carried out by adjusting the degree of reduced pressure stepwise at 0 ° C. For example, first, esterification is performed at normal pressure to remove water generated by the condensation reaction, and then 200 to 80 mm
A method is used in which the dehydration condensation reaction is further performed at a reduced pressure of about Hg to reduce the acid value and finally to a vacuum of 5 mmHg or less.

The reaction time can be shortened and the residual amount of the dihydroxy compound in the oligomer can be reduced by evaporating the excess dihydroxy compound and increasing the rate of increase in the degree of vacuum.

In the second step, the aliphatic polyester oligomer obtained in the first step is reacted with dicarbonate,
This is a process for producing an aliphatic polyester carbonate having a weight average molecular weight (Mw) by GPC in terms of styrene of at least 10,000 and a melting point of 50 to 180 ° C. Usually 150 to 280 ° C, preferably 200 to 220
C. to remove hydroxy compounds or water by-produced during the reaction. At a temperature of 150 ° C. or lower, a sufficient reaction rate cannot be obtained. At a temperature of 280 ° C. or higher, the polymerization reaction can proceed rapidly, but the polymer may be colored, which is not preferable. In the reaction, it is preferable that the degree of reduced pressure is gradually adjusted as necessary to finally reduce the pressure to 3 mmHg or less.

In order to facilitate pelletization when a low molecular weight product is produced, a nucleating agent can be added in the first step or the second step. Examples of the crystal nucleating agent include talc, mica, calcium carbonate, boron nitride and the like.
1 to 1 part by weight.

The oligomer obtained in the first step can be used in applications requiring a low molecular weight and a low viscosity upon melting. If a certain degree of viscosity is required at the time of melting, a method of increasing the viscosity as much as possible in the first step and increasing the molecular weight with a coupling agent or the like is also possible. However, it is preferable to proceed to the second step in order to obtain a high molecular weight material having excellent thermal stability.

The amount of dicarbonate added in the second step is
As determined by the oligomer molecular weight in the first step, the more the dicarbonate is added, the lower the melting point of the obtained polymer. Therefore, depending on the amount of dicarbonate added,
The heat radiation temperature or the melting temperature can be set according to the application.

The transesterification catalyst used in the first and second steps comprises a Zr compound or Hf compound, Y, La,
At least one selected from Zn and Sn compounds,
It is added in the range of 5 × 10 ⁻⁵ to 1 part by weight based on 100 parts by weight of the starting compound.

The catalyst used in the present invention is selected from transesterification catalysts. Particularly, a zirconium (Zr) compound or a hafnium (Hf) compound, and Y, La, Z
It is composed of a composite system comprising a combination of at least one compound of n and Sn, and is used in a range of 5 × 10 ⁻⁵ to 1 part by weight based on 100 parts by weight of the raw material mixture. Preferred forms of the compound as the catalyst include various salts such as fatty acid salts, hydroxides, alcoholates, phenolates, and acetylacetonates.

The glycol used in this step is
Aliphatic glycols having a straight-chain, branched or alicyclic structure having 2 to 20 carbon atoms are used. Specifically, ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, octanediol, neopentyl Examples include, but are not limited to, glycol, cyclohexanedimethanol, tricyclodecadimethanol, pentacyclodecadimethanol, and the like. Selection is possible depending on the melting point of the material, etc.
Considering physical properties, 1,4-butanediol is preferred.

As the aliphatic dibasic acid of the present invention, succinic acid is used as an essential component. In addition, for example, oxalic acid, malonic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, azelaic acid An acid, maleic acid, fumaric acid and the like can be appropriately used in combination. The above aliphatic dibasic acids may be esters or acid anhydrides thereof.

Examples of the hydroxycarboxylic acid compound used in the present invention include lactic acid, glycolic acid, β-hydroxybutyric acid, hydroxypivalic acid, hydroxyvaleric acid and the like, and these can also be used as derivatives such as esters and cyclic esters. .

These aliphatic dibasic acids, aliphatic dihydroxy compounds and hydroxycarboxylic acid compounds can be used alone or as a mixture and can be combined in any desired manner. It is preferable that the material has a melting point and a melting point high enough to realize practical heat resistance. Therefore, in the present invention, it is preferable that 1,4-butanediol as an aliphatic dihydroxy compound and succinic acid as an aliphatic dibasic acid each contain 50 mol% or more.

In the present invention, a compound having three or more functions can be added as a branching agent in order to improve the shape stability at the time of melting. As the branching agent, any of an aliphatic compound and an aromatic compound can be used as long as the total amount of the hydroxyl group and the carboxylic acid group is three or more.

Further, an aliphatic polyester carbonate obtained by reacting the aliphatic polyester obtained in the second step with a carbonate compound is also preferable. Specific examples of the carbonate compound used for producing the aliphatic polyester carbonate include diphenyl carbonate,
Diaryl carbonates such as ditolyl carbonate, bis (chlorophenyl) carbonate, and m-cresyl carbonate; and aliphatic carbonate compounds such as dimethyl carbonate, diethyl carbonate, diisopropyl carbonate, dibutyl carbonate, diamil carbonate, and dioctyl carbonate. However, the present invention is not limited to these. In addition to the above-mentioned carbonate compound composed of the same type of hydroxy compound, an asymmetric carbonate compound or a cyclic carbonate compound composed of a different type of hydroxy compound can also be used.

When the dicarbonate is added in the second step,
Block copolymerization is possible by adding a glycol component. The glycol to be added may be the same or different from the glycol used in the first step.

As the aliphatic polyester resin of the present invention, those having a high molecular weight, such as injection molding, extrusion molding, inflation method, T-die method, spinning, filament molding, blow molding, vacuum pressure molding or foam molding. Molding by a usual molding technique is possible. In addition, fillers, antioxidants, stabilizers, nucleating agents, ultraviolet absorbers, lubricants, waxes, coloring agents, which are usually added to the polymer as needed.
Additives such as colorants, contents, fillers and the like can be added.

When a molded article is obtained using the aliphatic polyester resin of the present invention, the molecular weight of the polymer to be used is appropriately selected depending on the molding conditions, the type of the molded article, the molding temperature and the like, and is measured by GPC. Those having a weight average molecular weight Mw of 10,000 to 300,000 in terms of styrene are used.

The melt viscosity of the aliphatic polyester resin is from 500 to 30,000 poise. This melt viscosity is a melt viscosity measured by a flow tester at a temperature of 190 ° C. under a load of 60 kg.

It is also possible to use the composition containing the aliphatic polyester of the present invention. The content of the aliphatic polyester in the composition must be at least 5%, and below this, the effect of the present invention is small. As a method of containing, it is possible to use either copolymerization or blending, and it is also possible to contain an inorganic filler. Further, the aliphatic polyester of the present invention can be used as a heat-shrinkable film or a heat-shrinkable label.

In the case of copolymerization, there is no particular limitation as long as it is a method of copolymerizing an aliphatic polyester in a block state, and aromatic and / or aliphatic polyester, aromatic and / or aliphatic polycarbonate, nylon, It can be copolymerized with polyolefin and the like. When the present material is blended, the resin to be mixed is not particularly limited, and aromatic and / or aliphatic polyester, aromatic and / or
Alternatively, it can be blended with aliphatic polycarbonate, nylon, polyolefin and the like.

Next, an example of a method of using the present material will be described.
Here, the case where an aliphatic polyester carbonate (a copolymer of 90% aliphatic polyester and 10% aliphatic polycarbonate) is used will be described.

In producing a multilayer film, a multilayer sheet or a multilayer laminate, a film or sheet made of the present material is superimposed on a film, sheet or paper of a polymer different from the present material (hereinafter referred to as a different polymer). After or at the same time as the irradiation with microwaves, the layers can be multilayered by pressing with a roll or the like. At this time, since the heterogeneous polymer does not absorb microwaves, there is no significant change in the thickness, and a multilayer film with good thickness accuracy is obtained. It should be noted that a multilayer film can be produced by a usual molding method using melt coextrusion, dry lamination, or an adhesive, and sufficient strength can be exhibited by the excellent physical properties of the resin itself of the present invention.

When the resin of the present invention is multi-layered and used for an adhesive surface, heat sealing by a normal heat sealer is sufficiently possible, but heat welding by microwave is possible.
This is particularly effective when it is not desired to directly heat another film layer. When the present resin is used as an adhesive layer, bonding can be performed by sandwiching the present resin formed in a film, sheet, rod shape or other form at a portion to be bonded, heating with microwaves, and pressing.

The polymer layer which can be multi-layered, laminated or adhered by the resin is not particularly limited, but may be aromatic and / or aliphatic polyester, aromatic and / or aliphatic polycarbonate, nylon, polyolefin, vinyl chloride, And polyethers. More specifically, PET, PBT, polycaprolactone, polyhydroxybutyrate, polylactic acid, polyglycolic acid, polycarbonate, 6 nylon, 6,6-nylon, 6, T-nylon, MXD6 nylon, polyethylene, polypropylene, polystyrene , ABS resin, PM
MA, polyoxymethylene, modified polyphenylene oxide, PPS, PEEK and the like are exemplified.

The aliphatic polyester and polyester carbonate materials comprising a glycol and an aliphatic dibasic acid compound of the present invention also have biodegradability by microorganisms,
It is also possible to obtain a biodegradable molded product by selecting a resin to be decomposed by microorganisms for other resins to be combined.

As described above, according to the present invention, the use of an aliphatic polyester which absorbs microwaves with sufficient moldability and processability enables the use of microwave-based multilayers,
Various processes such as laminating, laminating, and bonding are possible.

Next, the present invention will be described in more detail with reference to examples. Here, a case mainly using an aliphatic polyester carbonate obtained by using 1,4-butanediol as a glycol component, succinic acid as an aliphatic dibasic acid compound, and diphenyl carbonate as a dicarbonate ester will be mainly described.

In this example, the molecular weight was measured using GPC (GPC Sys, manufactured by Showa Denko KK) using chloroform as a solvent.
tem-11) using a styrene-equivalent weight average molecular weight (Mw) and a number average molecular weight (Mn). The residual amount of the unsaturated bond is determined by NMR (JEOL Ltd.)
The measurement was carried out using NMR EX-270 manufactured by KK.

The melt flow rate of the aliphatic polyester or aliphatic polyester carbonate was measured at 190 ° C. under a load of 2.1 using a melt indexer (Toyo Seiki).
It was measured at 6 kg.

The hydroxyl value and acid value of the aliphatic polyester oligomer were measured according to JIS K-1557. From the measured value of the hydroxyl value, the mole of the terminal hydroxyl group per unit weight was determined, and the half amount was defined as the theoretical amount of the dicarbonate and / or dicarboxylic acid compound.

Production Example 1 18,740 g of succinic acid was placed in a 50-liter reaction vessel equipped with a stirrer, a distillation condenser, a thermometer, and a gas inlet tube.
(158.7 mol), 1,4-butanediol 21,4
30 g (237.8 mol), 745 mg of zirconium acetylacetonate and 1.40 g of zinc acetate were charged and reacted under a nitrogen atmosphere at a temperature of 150 to 220 ° C. for 2 hours to distill water. Then, the degree of decompression is 150-80m
Aging was performed for 3 hours at a reduced pressure of mHg to advance the dehydration reaction, and finally the reduced pressure was gradually increased to a final reduced pressure of 2 mmHg or less to further distill water and 1,4-butanediol, and total distillation The reaction was stopped when the amount reached 10,460 g. The number average molecular weight of the obtained oligomer is 1,7.
80, the terminal hydroxyl value was 102 KOH mg / g, and the acid value was 0.51 KOH mg / g.

Next, 24,000 g of the obtained oligomer was charged into a 50-liter reaction vessel equipped with a stirrer, a fractionating condenser, a thermometer and a gas inlet tube, and 4,680 g of diphenyl carbonate was added. Temperature 210-220 ° C
The reaction was finally performed under reduced pressure of 1 mmHg for 5 hours. The obtained high molecular weight product (A-1) has a melting point of 104 ° C. and a GP
The weight average molecular weight (Mw) measured by C is 238,00.
0 and MI was 2 g / 10 min. According to 13 C NMR measurement, it had 14.3% of carbonate units as a polycarbonate component.

The obtained pellets of the high molecular weight substance (A-1) were dried by a vacuum dryer at a temperature of 90 ° C. for 5 hours, and supplied to an extruder (screw diameter: 20 mmφ, L / D = 25).
1 through a 200 mm wide T-die attached to the extruder
Extruded at a temperature of 85 ° C, a sheet (B-1) having a thickness of 1 mm
And a 50 μm film (B-2). B-
1 was a white plate, and B-2 was a milky white translucent film.

Example 1 When the sheet (B-1) obtained in Production Example 1 was irradiated with microwaves in a household microwave oven of 600 W, the sheet was heated and melted after 5 minutes to become transparent, and the resin temperature was lowered. 100
The degree had been reached.

Comparative Example 1 A 1 mm thick polycarbonate sheet was heated in a microwave oven in the same manner as in Example 1, but after 5 minutes the temperature of the sheet rose only slightly.

Example 2 A B-2 film was sandwiched between two polycarbonate sheets having a length of 10 cm, a width of 10 cm, and a thickness of 200 μm, and was irradiated with microwaves for 2 minutes in a home microwave oven. And it cooled and the multilayer sheet was obtained. The sheet had sufficient strength and did not peel off the sheet.

[0047]

According to the aliphatic polyester of the present invention,
Heat treatment with microwaves has made it possible to produce multilayer films made of different and / or similar resins.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 9:00 B29L 9:00 (72) Inventor Maki Ito 22 Wadai, Tsukuba, Ibaraki Pref. Mitsubishi Gas Chemical Co., Ltd. 4F100 AK01B AK41A BA02 EJ52 4F211 AA24 AA24E AA28E AG03 TA01 TA13 TC05 TD11 TH02 TH06 TJ09 TN13 TQ04 TW15

Claims (3)

[Claims] 1. A laminating step of laminating a polymer film in contact with at least one surface of an aliphatic polyester resin film, and then performing a heat treatment step of heating the aliphatic polyester resin film by microwave irradiation for laminating and bonding. A method for producing a multilayer film, comprising: 2. The aliphatic polyester resin is obtained by a polycondensation reaction of glycol with an aliphatic dibasic acid, an anhydride of an aliphatic dibasic acid or an ester of an aliphatic dibasic acid. Method for producing a multilayer film. 3. The method according to claim 1, wherein the glycol is mainly butanediol and the aliphatic dibasic acid is succinic acid and / or adipic acid.