JP2001054941A - Lactic acid polymer laminate for card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biodegradable lactic acid polymer laminate for a card having good heat fusibility, punching/cutting properties, embossing processability, card appearance and rigidity. SOLUTION: Lactic acid polymers (A), (B) contain 3-20 wt.% of a polyester structure unit obtained by the dehydrocondensation of dicarboxylic acid and diol and/or a polyether structure unit obtained by the dehydrocondensation of dicarboxylic acid and polyether polyol and 97-80 wt.% of a substrate unit originating from lactic acid and the lactic acid polymer (A) contains 7-22% by wt. of titanium oxide to lactic acid and a lactic acid polymer laminate for a card consists of a core layer (I) comprising the lactic acid polymer (A) and an overlay layer (II) comprising the lactic acid polymer (B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cash card used for payment and deposit at a financial institution such as a bank via an automatic payment machine, a credit card used for payment at a store, and a tape recording personal information. The present invention relates to a lactic acid-based polymer laminate for a card made of a biodegradable polymer that can be suitably used for a substrate generally called an information recording card, such as an ID card having a magnetic layer in the form of a card.

[0002]

2. Description of the Related Art Conventionally, a thermoplastic resin such as polyvinyl chloride resin (PVC) or polyethylene terephthalate (PET) has been used as a base material of an information recording card.
These information recording cards are each provided with an extrusion-molded sheet having a thickness of about 100 μm called an overlay layer utilizing the transparency of a thermoplastic resin, on both surface layers of the card, and a core layer to which titanium oxide for imparting concealment properties is added. Called 280
An extruded sheet having a thickness of about μm is provided in the middle layer of the card, and a tape-shaped magnetic material is further laminated on one surface layer of the card.

[0003] PVC and PET not only have good transparency and heat sealability, but also have appropriate flexibility.
When processing into a card, embossing is performed by using a punch with a concave / convex shape to make it possible to punch out and cut at once using a punching blade having the shape of a card, and to use a plate with irregularities in order to clarify the important printing part of the card. Excellent in nature.

The overlay layer and the core layer constituting the card are formed by extrusion molding. The former is about 100 μm and the latter is 280 μm.
It is processed into a sheet having a constant thickness of about μm. The core layer is printed as needed. A typical configuration of a credit card is an overlay layer / core layer / core layer / overlay layer. A magnetic tape is attached to this laminated body and heat-sealed, cut into a size of about 85 mm × 54 mm, and embossed or the like is applied to produce a credit card.

[0005] However, thermoplastic resins that have been conventionally used are known to have excellent chemical stability, do not readily decompose when disposed of in the natural world, and remain semipermanently in their original form. And its disposal has caused pollution problems for the natural environment. In other words, when discarded in a natural environment without any care, the landscape is impaired, marine organisms, birds and the like are erroneously eaten, and this contributes to a decrease in valuable biological resources.

[0006] In order to solve these problems, biodegradable polymers have recently been actively studied. Among them, polylactic acid has excellent transparency, easily decomposes in the natural environment, eventually turns into water and carbon dioxide, and has low calorie burning, so that it does not hurt the furnace even when incinerated. It has the characteristic of not generating harmful gas during combustion. In addition, since renewable plant resources can be used as a starting material, it is an environmentally circulating polymer. Due to these advantages, it is expected to be used as a substitute for thermoplastic resins conventionally used from petroleum resources.

[0007] However, polylactic acid composed of 100% lactic acid component has excellent transparency, but is poor in flexibility and relatively hard and brittle, so that processing characteristics such as punching and cutting properties and embossing properties in card processing are required. Had a problem.

[0008]

The problem to be solved by the present invention is to provide a biodegradable lactic acid-based polymer laminate for cards having good heat-sealing properties, punch-cutting properties, embossability, card appearance and rigidity. Is to provide the body.

[0009]

Means for Solving the Problems The present inventors consider that a polyester structural unit obtained by dehydration-condensation of a dicarboxylic acid and a diol and / or a polyether structural unit obtained by dehydration-condensation of a dicarboxylic acid and a polyether polyol have a content of 3 to 20% by weight. %
And lactic acid-based copolymers (A) and (B) each containing 97 to 80% by weight of a structural unit derived from lactic acid, and the polymer (A) contains 7 to 22% by weight of titanium oxide based on the lactic acid-based polymer. It has been found that the object can be achieved by a lactic acid-based polymer laminate for a card comprising a core layer (I) composed of a polymer (A) and an overlay layer (II) composed of a lactic acid-based polymer (B). Reached.

That is, the present invention relates to (1) a polyester structural unit obtained by dehydration-condensation of a dicarboxylic acid and a diol and / or a polyether structural unit obtained by dehydration-condensation of a dicarboxylic acid and a polyether polyol; A lactic acid-based polymer (A) comprising 97-80% by weight of a structural unit derived therefrom, and a lactic acid-based polymer (A)
Contains 7 to 22% by weight of titanium oxide with respect to the lactic acid polymer, and comprises a core layer (I) composed of a lactic acid-based polymer (A) and an overlay layer (II) composed of a lactic acid-based polymer (B). A polymer laminate;

(2) The core layer (I) composed of the lactic acid-based polymer (A) and the overlay layer (II) composed of the lactic acid-based polymer (B) are (II) / (I) / (I) / (II) or (II) /
(I) / (II), wherein the lactic acid-based polymer laminate for a card according to (1) is laminated;

(3) Lactic acid-based polymers (A) and (B)
Comprises a lactic acid-based polymer in which residual monomers have been reduced by at least one of a deactivation treatment, a devolatilization treatment, and a reprecipitation treatment of a polymerization catalyst with a deactivator of the polymerization catalyst (1). ) Or a lactic acid-based polymer laminate for a card according to (2),

(4) The lactic acid-based polymer (A) or (B) is added with at least one of a polycarboxylic acid, an anhydride of a polycarboxylic acid, and a polyisocyanate. (1) The lactic acid-based polymer laminate for a card according to any one of (1) to (3), wherein the lactic acid-based polymer has a high molecular weight.

(5) The 1% secant modulus of each of the core layer composed of the lactic acid-based polymer (A) and the overlay layer composed of the lactic acid-based polymer (B) is 1.6 GPa or more (1) to (4). A lactic acid-based polymer laminate for a card according to any one of the above,

(6) A core layer (I) composed of a lactic acid-based polymer (A) and an overlay layer (II) composed of a lactic acid-based polymer (B) are separately produced by an extrusion molding method, and thereafter, the core layer (I) And a lactic acid-based polymer laminate for a card according to any one of (1) to (5), wherein the overlay layer (II) is laminated by heat fusion with the overlay layer as a surface layer;

(7) A laminate of a core layer (I) composed of a lactic acid-based polymer (A) and an overlay layer (II) composed of a lactic acid-based polymer (B) has a magnetic layer on at least one surface layer of the laminate (1) To (6) a lactic acid-based polymer laminate for a card according to any one of (1) to (6).

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The contents of the present invention will be described below in detail. The present invention provides a lactic acid-based polymer (A) and (B),
Contains a polyester structural unit obtained by dehydration-condensation of a dicarboxylic acid and a diol and / or a polyether structural unit obtained by dehydration-condensation of a dicarboxylic acid and a polyether polyol, and 3 to 20% by weight, and 97 to 80% by weight of a lactic acid-derived structural unit. A core layer (I) composed of a lactic acid-based polymer (A), which is a lactic acid-based copolymer and containing 7 to 22% by weight of titanium oxide, and an overlay layer (II) composed of a lactic acid-based polymer (B), preferably (II) ) / (I) / (I) / (II) or (II) / (I) / (II).

Taking into account the practical rigidity of the card and the punch-cutting and embossing properties during processing, the dicarboxylic acid and diol of the lactic acid-based polymer (A) to be the core layer and the lactic acid-based polymer (B) to be the overlay layer Is preferably 3 to 20% by weight, more preferably 5 to 20% by weight, more preferably 5 to 20% by weight.
１５15% by weight.

When the amount of the polyester structural unit and / or the polyether structural unit is less than 3% by weight, chips called burrs are easily generated at the time of punching in card processing, and the appearance is easily impaired. Further, at the time of embossing, the card base material does not stretch, so that problems such as the fact that printing does not clearly stand out and that the card is cracked easily occur, which is not preferable.

Conversely, if the polyester structural unit and / or polyether structural unit exceeds 20% by weight, the rigidity of the card will not be sufficient for practical use. That is, when the card is inserted into a discriminating machine such as an automatic dispensing device, deformation such as bending is likely to occur, which is not preferable.

Further, the core layer of the credit card needs to have a sufficient concealing property so that printing on the printing surface cannot be seen through to the opposite surface. A lactic acid-based polymer has good transparency and is therefore preferred as an overlay layer, but it is necessary to add a highly opaque coloring agent such as titanium oxide to the core layer.

Titanium oxide added to the core layer is preferably from 7 to 22% by weight, more preferably from 10 to 20% by weight, in consideration of sufficient concealing properties and extrusion workability. If it is less than 7% by weight, sufficient concealing properties cannot be obtained, and if it exceeds 22% by weight, stable film formation cannot be performed at the time of extrusion film formation to produce a sheet, and a core layer having a uniform thickness cannot be produced. If the thickness of the core layer is not good, air bubbles are contained at the time of heat fusion for producing a laminate with the overlay layer, and the appearance of the card is deteriorated. Further, when printing is performed, a defect such as missing of printing occurs.

As a scale for judging the rigidity, there is a measurement of a 1% secant modulus value using a tensile tester. 1%
The measured value of the secant modulus is JIS K-71
27 corresponds to the measurement of the tensile secant modulus at 1% strain. The 1% secant modulus values of the core layer composed of the lactic acid-based polymer (A) and the overlay layer composed of the lactic acid-based polymer (B) are each preferably 1.6 GPa or more, and more preferably 1.8 GPa or more. If it is less than 1.6 GPa, the card is likely to be bent or deformed when inserted into a discriminating machine such as an automatic teller machine.

The lactic acid polymer used in the present invention is a structural unit derived from a lactic acid component obtained by dehydrating and condensing lactic acid or lactide, a polyester structural unit obtained by dehydrating and condensing a dicarboxylic acid component and a diol component, and / or a dicarboxylic acid and a polyether polyol component. Is a lactic acid-based copolymer containing a polyether structural unit obtained by dehydration-condensation.

By improving the molecular weight of the lactic acid-based polymer, mechanical workability such as punching and cutting properties can be further improved. The weight average molecular weight of the lactic acid polymer used in the present invention is preferably about 50,000 to 500,000, and more preferably 100,000 to 400,000. If it is less than 50,000, mechanical properties are inferior.
Not practical. On the other hand, when it exceeds 500,000, extrusion processability becomes poor when a core layer or an overlay layer made of a lactic acid-based polymer is produced.

The lactic acid component in the lactic acid-based copolymer used in the present invention is a condensed component of lactic acid, and these are L, D, DL-lactic acid, which are optical isomers, or L, a cyclic dimer of these lactic acids. , D, DL-lactide, or polylactic acid obtained by polymerizing these, can be used as a raw material of the copolymer. As a method for producing polylactic acid, a method of obtaining a high molecular weight polylactic acid by ring-opening polymerization of lactide is widely used, but a method obtained by directly synthesizing polylactic acid by dehydration condensation from lactic acid is also used. .

The dicarboxylic acid component in the polyester component of the lactic acid copolymer used in the present invention includes, for example, adipic acid, sebacic acid, succinic acid, dimer acid and the like. The diol component has a main chain having 2 carbon atoms. ~ 6, such as ethylene glycol, propylene glycol, butylene glycol, 1,4-butanediol,
6-hexanediol and the like.

Examples of the polyether polyol component include polyethylene glycol, polypropylene glycol, polybutylene glycol and the like. Among these, it is most preferable to use adipic acid, sebacic acid or dimer acid as the dicarboxylic acid component, propylene glycol as the diol component, and polypropylene glycol as the polyether polyol.

The lactic acid-based copolymer used in the present invention is an aliphatic polyester, an aromatic polyester, caprolactone, acetic acid or the like having the above-mentioned dicarboxylic acid component, diol component or polyether polyol component during or immediately after the polymerization of polylactic acid. It can be obtained by adding one or more of vinyl, ethylene terephthalate polymer and ethylene vinyl alcohol, and further proceeding the polymerization.

At any stage of these polymerizations, any one or more high molecular weight agents such as polycarboxylic acids and / or acid anhydrides and polyisocyanates may be added.
The lactic acid-based polymer can be further increased in molecular weight. As the polyvalent carboxylic acid, any known and commonly used polyvalent carboxylic acid can be used without particular limitation.For example, trimellitic acid, pyromellitic acid, succinic anhydride as an acid anhydride,
Trimellitic anhydride, pyromellitic anhydride and the like can be mentioned.

As the polyvalent isocyanate, any known polyvalent isocyanate can be used without any particular limitation. Examples thereof include 2,4-tolylene diisocyanate and 2,2 tolylene diisocyanate.
A mixture of 4-tolylene diisocyanate and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, triphenylmethane-4, 4 ', 4 "-
And triisocyanates.

The amount of the high molecular weight agent to be added may be about 0.01 to 5% by weight based on the lactic acid-based polymer, and the weight-average molecular weight of the lactic acid-based polymer, which usually rises only to about 300,000, is 600,000 to 500,000. It can be raised to about 700,000.

Further, a chelating agent or an acid phosphate is added as a deactivator of the polymer polymerization catalyst during and / or after the polymerization of the polymer, thereby
It forms a complex with a metal ion in the polymerization catalyst contained in the polymer, loses its activity, and can greatly improve the thermal stability and storage stability of the composition.

As the chelating agent used, there are an organic chelating agent and an inorganic chelating agent. Organic chelating agents include, but are not limited to, amino acids, phenols, hydroxycarboxylic acids, diketones, amines,
Oximes, phenanthrolines, pyridine compounds, dithio compounds, N-containing phenols as coordinating atoms, N-containing carboxylic acids as coordinating atoms, diazo compounds, thiols,
And porphyrins.

Specific examples of the inorganic chelating agent include phosphoric acids such as phosphoric acid, phosphorous acid, pyrophosphoric acid and polyphosphoric acid. They have high hygroscopicity and lose their effect if they absorb moisture, so care must be taken when handling them.

The amount of the chelating agent varies depending on the type of the chelating agent used and the type and amount of the catalyst contained in the lactic acid-based polymer.
It is preferable to add 1 to 5 parts by weight, or 0.1 to 100 parts by weight based on 1 part by weight of the used catalyst.
Further, a mixture of an organic chelating agent and an inorganic chelating agent may be used.

The acidic phosphoric acid esters include acidic phosphoric acid esters, phosphonic acid esters, alkylphosphonic acids and the like, and mixtures thereof. In acid phosphates,
In particular, acidic phosphates have a great effect on catalyst deactivation. The amount of the acidic phosphoric acid ester added is preferably 0.001 to 5 parts by weight based on the lactic acid-based polymer, or 0.1 to 100 parts by weight based on 1 part by weight of the catalyst used. .

In addition to deactivating the polymerization catalyst with the deactivator of the polymerization catalyst, there is a devolatilization method in which the lactic acid-based polymer is heated and devolatilized under reduced pressure as a method for physically reducing the residual monomers and oligomers. Concrete devolatilization is performed by a single-screw or twin-screw extruder, a thin-film evaporator, a pot-type decompression device, or the like.

For devolatilization, it is preferable to take out the lactic acid-based polymer while heating under reduced pressure after polymerization.
The devolatilization conditions for preventing the molecular weight of the lactic acid-based polymer from being lowered include a devolatilization time of 10 seconds to 10 minutes and a temperature of 100 to 230.
° C, the degree of decompression is 0.1 to 50 Torr, more preferably 0.1 to 10 Torr, and still more preferably 0.1 to 5 Torr.
rr.

There is also a method in which the lactic acid-based polymer is pelletized or pulverized after the polymerization is completed, and the lactic acid-based polymer is taken out while heating under reduced pressure. Also in this case, for the purpose of not lowering the molecular weight of the lactic acid-based polymer, the devolatilization time is 2 to 400 minutes, the temperature is 60 to 200 ° C., the degree of reduced pressure is 0.1 to 50 Torr, more preferably 0.1 to 10 Torr, and still more preferably. Is 0.1 to 5 Torr.

Further, after the polymerization, the lactic acid-based polymer is taken out, and when processing into a sheet using a single-screw or twin-screw extruder or the like, a vent port or the like is provided in the extruder to perform devolatilization. The same devolatilizing effect can be obtained. Also in this case, for the purpose of not lowering the molecular weight of the lactic acid-based polymer, the devolatilization time is 10 seconds to 10 minutes, the temperature is 145 to 230 ° C., and the degree of pressure reduction is 0.1 to 50 Torr, preferably 0.1 to 10 Torr.
r, more preferably 0.1 to 5 Torr.

Further, there is a reprecipitation method in which after the polymerization reaction is completed, the lactic acid-based polymer is dissolved in a solvent and added to a poor solvent to obtain a lactic acid-based polymer having a small amount of residual monomers. Solvents that dissolve lactic acid-based polymers include benzene, toluene, ethylbenzene, xylene, cyclohexane, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, methyl isobutyl ketone, methyl ethyl ketone, isopropyl ether, dichloromethane, chloroform, carbon tetrachloride, chlorobenzene, Chlorobenzene, trichlorobenzene, chloronaphthalene and the like can be mentioned.

These solvents may be used alone or as a mixture. Water, methanol,
Ethanol, propanol, butanol, pentane, octane, nonane, decane, diescyl ether and the like, and a mixed solvent thereof can be mentioned. In the reprecipitation method, a lactic acid-based polymer is dissolved in a solvent at a concentration of 2 to 20% by weight at room temperature or while heating, and then gradually added to a poor solvent of 2 to 15 times the amount with stirring, and the solution is allowed to stand for 10 to 180 minutes. Place to generate precipitate and remove. The removed precipitate removes residual solvent under reduced pressure and / or under heating.

The method for reducing the residual monomers and oligomers includes a method for preventing the generation of residual monomers and oligomers by a deactivator of the polymerization catalyst, and a method for mechanically removing residual monomers and oligomers such as a devolatilization method and a reprecipitation method. There are ways to exclude. The lactic acid-based polymer used in the present invention is preferably a lactic acid-based polymer in which residual monomers and oligomers have been reduced by any one of these methods. good.

The lactic acid-based polymer used in the present invention can be reduced to 2% by weight or less, more preferably 1% by weight or less, further preferably 0.1% by weight or less, by these treatments. preferable. By reducing the residual monomers and oligomers, the storage stability can be increased, and further, during extrusion molding, adhesion of the residual monomers and oligomers to the cooling roll and the forming die can be prevented, and the appearance of the product can be prevented from being impaired.

The core layer made of the lactic acid-based polymer (A) and the overlay layer made of the lactic acid-based polymer (B) of the present invention may contain other polymer or second component as the second and / or three components as long as the effects of the present invention are not impaired. It may contain additives such as a plasticizer, a stabilizer, an antioxidant, an antiblocking agent, an antifogging agent, a colorant, and a dispersant. Other polymers include aliphatic polyesters, polyvinyl alcohol, polyhydroxybutyrate-hydroxyvalerate, starch-based polymers, and the like.

Examples of the additives include polyester plasticizers such as 1,3-butanediol and adipic acid, and plasticizers such as dioctyl phthalate and polyethylene glycol adipic acid.
Epoxidized soybean oil, stabilizers such as carbodiimide, t-
Antioxidants such as butyl-4-methylphenol (BHT) and butyl hydroxyanisole (BHA), antiblocking agents such as silica and talc, glycerin fatty acid esters, antifoggants such as monostearyl citrate, oxidation Colorants such as titanium and ultramarine, and dispersants of fatty acids such as stearic acid, oleic acid, and lauric acid are included.

Next, a method for producing an overlay layer and a core layer comprising the lactic acid-based polymer of the present invention will be described. The overlay layer and the core layer made of a lactic acid-based polymer are efficiently produced by an extrusion molding method. Lactic acid-based polymers have high hygroscopicity and strong hydrolyzability, so moisture management is necessary.
When extrusion molding is performed using a general single-screw extruder, it is necessary to efficiently dehydrate the polymer through the vent port of the extruder, or to dehumidify and dry the polymer using a dehumidifying dryer or vacuum dryer before film formation. is there. Film formation by a vented twin-screw extruder has a high dewatering effect, and enables efficient film formation.

The melt extrusion temperature when forming the lactic acid-based polymer is not particularly limited, but is usually in the range of 150 to 250 ° C. The melt-extruded sheet is cast to a predetermined thickness, and is cooled if necessary. At that time, a uniform sheet is formed by using a touch roll, an air knife, and electrostatic pinning. Among them, a touch roll can transfer a mirror surface to a sheet, and can improve the appearance of the sheet. The interval between the lips for performing the melt extrusion is generally 0.2 to 5.0 mm, but 0.2 to 3.0 mm is more preferable in consideration of the film forming property.

In order to prevent the lactic acid-based polymer from absorbing moisture, it is desirable that the raw material supply port of the extruder be in an absolutely dry state or an environment in which nitrogen or the like is purged. Lactic acid based polymer
Addition of titanium oxide to (A) may be carried out by blending with a lactic acid-based polymer before extrusion molding, or may be carried out by continuous mixing such as an auto feeder at a desired blending ratio into a raw material supply port of an extruder while performing extrusion molding. You may use the apparatus which can mix.

A more preferable method is to use a twin-screw extruder to improve dispersibility and handling in the lactic acid-based polymer.
Using a Banbury mixer or the like, add 50 parts of titanium oxide in advance.
A masterbatch mixed at a high concentration of about weight% or more is prepared, and the masterbatch is added to the lactic acid-based polymer so that the titanium oxide in the core sheet has a desired concentration during extrusion molding.

At this time, if the added amount of titanium oxide exceeds 22% of the whole polymer, the back pressure at the time of extrusion film formation becomes unstable and the sheet thickness becomes difficult to be constant. In addition, in order to prevent hydrolysis of the lactic acid-based polymer during thermal processing, it is preferable that the titanium oxide be previously dehydrated using a vacuum dryer or a dehumidifying dryer. Suitable drying conditions are 80 ° C. for 2 hours for vacuum drying and about 2 hours at 120 ° C. for a dehumidifying dryer.

Titanium oxide is classified into a rutile type and an anatase type depending on the crystal form, and either one may be added to the lactic acid-based polymer. More preferably, it is a rutile type which has a bluish hue and is beautiful when added to a lactic acid-based polymer.
Considering the handling during processing such as addition, the concealing property of the core and the appearance of the card, the average particle diameter of the titanium oxide used is preferably 0.1 to 0.3 μm, more preferably 0.1 μm.
5 to 0.25 μm. The average particle system is obtained by observing a single particle system with an electron microscope.

The overlay layer (sheet) formed by extrusion film formation can be subjected to a matting treatment as required in order to improve the heat fusion property with the core layer (sheet). In order to perform the matting process efficiently, the molten resin sheet discharged from the die for forming the sheet at the time of extrusion film formation is cast on a casting roll (cooling roll) at regular intervals of 1 to 100 μm with a fine and uneven roll. There is a method of sandwiching and transferring the irregularities.

The sheet to be the core layer and the sheet to be the overlay layer produced by extrusion film formation are laminated as an overlay layer / core layer / core layer / overlay layer or an overlay layer / core layer / overlay layer, respectively.
The lactic acid-based laminate for a card is produced by heat fusion by heating from both surface layers or one side. The heating temperature for heat fusion is preferably from 120C to 150C, more preferably from 130C to 150C.
C. to 140C.

Thereafter, the shape of the card, approximately 85 mm × 5
The card is punched out to a size of 4 mm. The core layer is printed as necessary before lamination, but the surface of the core layer is chemically etched by corona discharge treatment, flame plasma treatment, chromic acid treatment, etc. before printing in order to improve the adhesion of printing ink. Treatment, surface treatment such as ozone / ultraviolet treatment, or surface unevenness treatment such as sandblasting can be improved.

If the heat bonding property between the core layer and the overlay layer is poor, a chemical etching treatment such as a corona discharge treatment, a flame plasma treatment, or a chromic acid treatment is performed before the core layer or the overlay layer is thermally fused. By selecting a surface treatment such as an ozone / ultraviolet treatment or a surface unevenness treatment such as a sand blast, the heat fusion property can be improved.

At the time of heat fusion between the core layer and the overlay layer, a tape having an adhesive and a magnetic material is laminated on one surface of the card, and the magnetic material is transferred from the tape to the card. At present, a polyester-based adhesive is used for a card based on PET, and a mixed adhesive of vinyl acetate and urethane resin is used for a card based on PVC. Either adhesive can be used for the lactic acid-based polymer laminate of the present invention, but it is preferable to use a magnetic tape using a polyester-based adhesive from the viewpoint of adhesiveness.

Further, it is possible to use an adhesive containing a diol, a dicarboxylic acid and / or a polyether polyol component constituting a polyester component or a polyether component as a component in the lactic acid-based polymer of the present invention. It is preferable from the viewpoint of the adhesive strength between the card and the magnetic material. As for the magnetic material, a material commonly used in the art can be used. For example, cobalt ferrite using cobalt,
Examples include chromium dioxide using chromium, aluminum Heusler alloy using manganese, iron oxide such as magnetite using iron, nickel ferrite, and yttrium iron garnet.

The core layer and the overlay layer constituting the lactic acid-based polymer laminate for a card according to the present invention are not made from blends having different thermal properties, but contain polyester structural units and / or polyether structural units. The use of a lactic acid-based copolymer adjusted to give an overlay layer and a core layer having a good appearance when extrusion molding is performed.

Moreover, since the overlay layer has excellent transparency, the printed surface of the core layer can be seen beautifully, and it can be punched and cut into a card shape and embossed so that prints can be embossed. It has excellent rigidity suitable for use.

The core layer composed of the lactic acid-based polymer (A) and / or the overlay layer composed of the lactic acid-based polymer (B) of the present invention may have a glass transition of the lactic acid-based polymer, if necessary, for the purpose of further improving the mechanical properties. The stretching treatment can be performed at a temperature of about 55 ° C. or higher and a crystallization temperature of about 80 ° C. or lower.

The stretching method is not particularly limited, but is performed immediately after melt-extrusion of the lactic acid-based polymer, after laminating or after storage, rolling, longitudinal uniaxial stretching, horizontal uniaxial stretching, simultaneous biaxial stretching, sequential biaxial stretching. It can be performed by any of axial stretching, and can be performed up to about 16 times in area magnification.

If the lactic acid-based polymer is crystalline, crystallization can be performed at a crystallization temperature of about 80 ° C. or higher and a melting point of about 160 ° C. or lower to improve heat resistance. In order to perform the crystallization efficiently, it is preferable to perform the crystallization after performing the stretching. Usually, a processing time that requires several minutes to several tens minutes is 10 seconds to
This can be performed in about 60 seconds, and the overlay layer can maintain transparency.

[0065]

EXAMPLES The present invention will be described in detail with reference to examples. First, a method for producing the lactic acid-based polymer used in the present invention will be described.

(Preparation of lactic acid-based polymer) Aliphatic polyester (weight average molecular weight: 35,000 (in terms of polystyrene), sebacic acid 50 mol%, 1,6-hexanediol 20 mol%, ethylene glycol 20 mol%, 1,3
97 parts by weight of lactide (99 mol% of L-lactide and 1 mol% of D-lactide) were added to 3 parts by weight of butanediol (10%), and the atmosphere was replaced with an inert gas.
The mixture was mixed at 1 ° C. for 1 hour, and 0.02 parts by weight of tin octoate was added as an esterification catalyst, followed by a reaction for 8 hours.

Thereafter, 0.04 parts by weight of an acidic phosphoric acid ester as a deactivator was added and kneaded, and the mixture was heated with a twin-screw extruder and devolatilized under reduced pressure. The devolatilization condition is that the devolatilization time is 12
0 seconds, the temperature is 200 ° C., and the degree of pressure reduction is 5 Torr. The obtained lactic acid-based polymer was a colorless and transparent resin, and the weight-average molecular weight was 200,000 as measured by GPC. This polymer is called P1.

Aliphatic polyester (weight average molecular weight:
35,000 (in terms of polystyrene), 50 mol% of sebacic acid, 20 mol% of 1,6-hexanediol, 20 mol% of ethylene glycol, 10% of 1,3-butanediol
30 parts by weight of lactide (98 mol% of L-lactide,
D-lactide 2 mol%), and the atmosphere was replaced with an inert gas, followed by mixing at 170 ° C. for 1 hour,
0.02 parts by weight of tin octoate was added as an esterification catalyst, and the mixture was reacted for 8 hours.

Thereafter, 0.04 parts by weight of an acidic phosphoric acid ester as a deactivator was added and kneaded. Further, devolatilization was carried out under heating and reduced pressure by a twin screw extruder. The devolatilization condition is that the devolatilization time is 12
0 seconds, the temperature is 200 ° C., and the degree of pressure reduction is 5 Torr. The obtained lactic acid-based polymer was a colorless and transparent resin, and the weight average molecular weight was 140,000 based on the result of GPC measurement. This polymer is called P2.

Aliphatic polyester (weight average molecular weight:
650,000 (in terms of polystyrene), 15 mol parts of dimer acid and 50 mol% of propylene glycol, and 85 parts by weight of lactide (96 mol% of L-lactide, 4 mol% of D-lactide) were added to give The atmosphere was replaced with an active gas, and the mixture was mixed at 170 ° C. for 1 hour. Then, 0.02 parts by weight of tin octoate was added as an esterification catalyst, and the mixture was reacted for 8 hours.

Thereafter, 0.04 parts by weight of an acidic phosphoric acid ester as a deactivator was added and kneaded, followed by heating with a twin screw extruder.
Devolatilization was performed under reduced pressure. The conditions for devolatilization are as follows:
Second, the temperature is 200 ° C., and the degree of reduced pressure is 5 Torr. The obtained lactic acid-based polymer was a transparent resin, and the weight-average molecular weight was 1370,000 as measured by GPC. This polymer is called P3.

The atmosphere was replaced with an inert gas containing 96 mol% of L-lactide and 4 mol% of D-lactide, mixed at 165 ° C. for 1 hour, and added with 0.02 parts by weight of tin octoate as an esterification catalyst. A time reaction was performed. After this,
As a deactivator, 0.04 parts by weight of an acidic phosphoric acid ester was added and kneaded. Further, devolatilization was carried out under heating and reduced pressure by a twin screw extruder. The devolatilization conditions were as follows: devolatilization time was 120 seconds, temperature was 200 ° C,
The degree of pressure reduction is 5 Torr. The obtained lactic acid-based polymer was a colorless and transparent resin, and the weight average molecular weight was 272,000 from the result of GPC measurement. This polymer is called P4.

Aliphatic polyester (weight average molecular weight:
35,000 (in terms of polystyrene), 50 mol% of sebacic acid, 20 mol% of 1,6-hexanediol, 20 mol% of ethylene glycol, 10% of 1,3-butanediol
5 parts by weight of lactide (L-lactide 99 mol%, D
95% by weight of lactide), the atmosphere was replaced with an inert gas, and the mixture was mixed at 170 ° C. for 1 hour. Then, 0.02 part by weight of tin octoate was added as an esterification catalyst, 1% of pyromellitic acid is added as
The reaction was performed for 8 hours.

Thereafter, 0.04 parts by weight of an acidic phosphoric acid ester as a deactivator was added and kneaded. Further, devolatilization was carried out under heating and reduced pressure by a twin screw extruder. The devolatilization condition is that the devolatilization time is 12
0 seconds, the temperature is 200 ° C., and the degree of pressure reduction is 5 Torr. The obtained lactic acid-based polymer was a colorless and transparent resin, and the weight average molecular weight was 350,000 based on the result of GPC measurement. This polymer is called P5.

(Examples 1 to 6) A single-screw extruder (effective cylinder length / cylinder) was prepared by using a lactic acid-based polymer shown in Tables 1 and 2 and titanium oxide (Taipe CR-60 manufactured by Ishihara Sangyo Co., Ltd.). An overlay layer having a thickness of 100 μm and a core layer having a thickness of 280 μm, which constitute a credit card, were manufactured with a diameter of 24 mm and a diameter of 50 mmφ. Tables 1 and 2 show the amounts of titanium oxide blended in the core layer.

In Example 5, each sheet is prepared from a blend of two lactic acid-based polymers. Table 2 shows the types and blend ratios of the resins. The core layer obtained here was printed on one side, an overlay layer was laminated on the printing side, and a card laminate was produced by heat fusion. Tables 1 and 2 show the structure of the laminate. At this time, PET used for existing credit card
The transfer magnetic tape for the substrate was also bonded. afterwards,
The card was punched and cut into a card shape and embossed. Each evaluation method such as workability is shown below.

(Extrusion film-forming properties) It was evaluated whether or not a sheet having a constant thickness could be produced stably without a large discharge fluctuation when a core layer was made to contain titanium oxide and formed by extrusion. ：: Thickness in the sheet deposition direction is in the range of 252 μm to 308 μm. ×: The thickness in the sheet deposition direction is less than 252 μm, or
Those exceeding 308 μm.

(Hiding Property of Core Layer and Transparency of Overlay Layer) The haze value (%) of each sheet was measured in accordance with JISK-7105. (1) Evaluation of core layer; ：: 80% or more ：: 30% to less than 80% ×: less than 30%

(2) Evaluation of overlay layer: ◎: less than 1% ： １: 1% to less than 5% ×: 5% or more

(Rigidity of Core Layer and Overlay Layer) In the winding direction and width direction of each sheet, 1% at a tensile speed of 10 mm / min using a No. 1 type test piece according to JISK-7127.
Tensile secant modulus at strain (1% secant modulus) was measured and averaged. The evaluation criteria are as follows.

◎: 1.6 GPa or more ×: Less than 1.6 GPa

(Heat Fusing Property) The state when a core layer and an overlay layer were laminated and a laminate was produced by heat fusion was visually evaluated. Tables 1 and 2 show the structure of the laminate. Heating was performed while pressing from both sides of the laminate. Heating temperature is 135
~ 140 ° C. The evaluation criteria are as follows.

：: A layer which does not contain air bubbles between the core layer and the overlay layer, forms a laminate, does not peel off the magnetic material, and has good transfer. ×: A bubble is present between the core layer and the overlay layer, or the core layer and the overlay layer are easily peeled off and a laminate is not formed. Or, one in which peeling of the magnetic material is confirmed.

(Punching Cutability into Card Shape) The prepared laminate was punched out using a card-shaped punching blade. The appearance of the punched product was visually evaluated. The evaluation criteria are as follows.

：: No burrs or the like are generated on the punched card, and the side of the removed card is smooth. ×: The burrs or the like are generated on the punched card or the card is removed. The side is not smooth.

(Card Rigidity) The punched-out card was bent by hand and evaluated by touch. ：: Those which can be determined to have sufficient rigidity. ×: Rigidity is insufficient for use as a card.

(Embossability) The punched-out card was embossed with alphanumeric characters and the like, and the printed state was evaluated visually and tactilely.

：: Printing is sufficiently raised, and the state can be recognized by touch. ×: Printing is not sufficiently raised, and the state is difficult to understand even when touched. Or a cracked card.

(Printing Visibility of Card) The punched-out card was visually observed, and the condition of the printed surface printed on the core was evaluated. ：: The print is clearly visible without fogging or the like. X: The print is cloudy and cannot be clearly seen. Or, the print on the back of the card can be seen through.

(Biodegradability of card) 5 kg of garbage was put in an outdoor compost (capacity: 100 liters), and the obtained card was placed thereon. Further, the garbage having a thickness of about 5 cm was placed thereon, and the state of the card one month later was visually evaluated.
This test was performed in summer. The evaluation criteria are as follows.

：: Physical properties are remarkably deteriorated, and it is difficult to maintain the shape. X: No deformation or the like, and the state before the start of the test is maintained.

[0092]

[Table 1]

[0093]

[Table 2]

Comparative Examples 1 to 4 Lactic acid-based polymers shown in Table 3 and titanium oxide (Taipaek C manufactured by Ishihara Sangyo Co., Ltd.)
Using R-60), an overlay layer having a thickness of 100 μm and a core layer having a thickness of 280 μm constituting the card were produced by a single screw extruder (effective cylinder length / cylinder diameter = 24, diameter 50 mmφ).

The core layer obtained here was printed on one side, and an overlay layer was laminated on the printing side, and a card laminate was produced by heat fusion. Table 3 shows the configuration of the laminate.
At this time, the transfer magnetic tape for a PET base used for an existing credit card was also bonded. After that, it was punched and cut into a card shape and embossed. Each evaluation such as workability was performed in the same manner as in Examples 1 to 6. Table 3 shows the results.

[0096]

[Table 3]

[0097]

The lactic acid-based polymer laminate for cards of the present invention has good heat-sealing properties, punch-cutting properties, embossing properties, card appearance, rigidity, biodegradability, and is suitable for use in financial institutions such as banks. A base material generally called a record information card such as a cash card used for paying out and paying through an automatic dispenser, a credit card used for payment at a store, and an ID card having a magnetic layer on which personal information is recorded. Can be suitably used.

 ────────────────────────────────────────────────── ─── Continuing on the front page F term (reference) 2C005 HB09 JA08 KA01 KA15 KA37 KA70 LA03 LA09 LA18 LA20 LA29 4F100 AA21 AA21A AA21C AH02A AH02B AH02C AH02D AK41A AK41B AK41C AK41D BA04 BA30 BA04 BA10 BAK AK54A AK54 BAK CA30C CA30D EH17 GB90 JC00 JG06E JK01 JL01 JL12 YY00A YY00B YY00C YY00D 4J002 CF101 CF181 CF191 CK031 DE136

Claims (7)

[Claims] 1. A polyester structural unit obtained by dehydration-condensation of a dicarboxylic acid and a diol and / or a polyether structural unit obtained by dehydration-condensation of a dicarboxylic acid and a polyether polyol, and 3 to 20% by weight of a structural unit derived from lactic acid.
0% by weight of the lactic acid-based polymer (A) and (B), and the lactic acid-based polymer (A) contains 7 to 22% by weight of titanium oxide with respect to the lactic acid polymer. A lactic acid-based polymer laminate for a card, comprising a core layer (I) comprising the above and an overlay layer (II) comprising a lactic acid-based polymer (B). 2. The method according to claim 1, wherein the core layer (I) comprising the lactic acid-based polymer (A) and the overlay layer (II) comprising the lactic acid-based polymer (B) comprise (II) / (I) / (I) / (II) or (II). II) /
The lactic acid-based polymer laminate for a card according to claim 1, wherein the laminate is (I) / (II). 3. The method according to claim 1, wherein the lactic acid-based polymer (A) and the lactic acid-based polymer (B) are deactivated by a polymerization catalyst deactivator, devolatilized,
The lactic acid-based polymer laminate for a card according to claim 1 or 2, comprising a lactic acid-based polymer in which residual monomers have been reduced by at least one of a re-precipitation treatment and a re-precipitation treatment. 4. The lactic acid-based polymer (A) or (B) is obtained by adding a polyhydric carboxylic acid, an acid anhydride of a polycarboxylic acid, and a polyhydric isocyanate to one or more of high molecular weight agents. The lactic acid-based polymer laminate for a card according to any one of claims 1 to 3, comprising a lactic acid-based polymer having a high molecular weight. 5. The method according to claim 1, wherein the 1% secant modulus of each of the core layer composed of the lactic acid-based polymer (A) and the overlay layer composed of the lactic acid-based polymer (B) is 1.6 GPa or more. A lactic acid-based polymer laminate for a card according to one of the above. 6. A core layer (I) composed of a lactic acid-based polymer (A) and an overlay layer (II) composed of a lactic acid-based polymer (B) are separately produced by an extrusion molding method. The lactic acid-based polymer laminate for a card according to any one of claims 1 to 5, wherein the overlay layer (II) is laminated by heat fusion with the overlay layer as a surface layer. 7. A laminated body of a core layer (I) composed of a lactic acid-based polymer (A) and an overlay layer (II) composed of a lactic acid-based polymer (B) has a magnetic layer on at least one surface layer. 7. The lactic acid-based polymer laminate for a card according to any one of 6.