JPH09123358A - Biodegradable card base material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a card base material which has excellent surface gloss, surface protective property, bending resistance, and biodegrades in the natural world by forming at least a support body and a protective layer which is oriented uniaxially or biaxially and is to be layered on both surfaces of the support body out of a composition having a biodegradable resin as a main component. SOLUTION: In a card base material formed of a thermoplastic resin, at least a support body and a protective layer oriented uniaxially or biaxially to be layered on the surface of the support body are formed of a composition having a biodegradable resin as a main component. For the support body consisting of the biodegradable resin, a layer consisting of a composition having a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate (PHB/V) as a main component or a layer consisting of a composition having the PHB/V and a caprolactam(PCL) as main components is used. For the protective layer, a layer consisting of a composition having the PHB/V and the PCL as main components or a layer consisting of a composition having the PCL and a poly(lactic acid) resin as main components is used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a biodegradable card substrate. More specifically, the present invention relates to a card substrate made of a biodegradable resin having a card support having excellent bending resistance and capable of being decomposed by natural microorganisms, and a protective layer laminated on the surface of the card support. .

[0002]

2. Description of the Related Art In recent years, credit cards, cash cards, pre-paid cards, telephone cards, medical examination tickets, commuter tickets, ID cards and the like have been widely used in daily life. As such a card base material, a resin that constitutes a support that imparts bending resistance, a support that is made of paper, etc. and surface glossiness (beauty) are imparted to protect the printing layer and retain the information recording layer. It is generally composed of a protective layer made of a film or a coating resin. Conventionally, as a resin constituting such a support and a protective layer,
Resins such as polyethylene terephthalate and polyvinyl chloride are used. The card base material made of such a resin is properly used according to the purpose of use, the period of use, and the frequency of use of the card, for example, formed into a sheet having a thickness of about 180 to 800 μm, and cut into a card shape for use. .

[0003]

However, such a card base material made of a resin such as polyethylene terephthalate or polyvinyl chloride is used when its intended use is completed or when a sheet or the like is cut into a card shape. The molding loss and the like that occur at the same time are incinerated or landfilled together with dust and the like. In the case of incineration treatment, a card base material or the like made of such a resin has a high calorific value, which tends to damage the incinerator and shorten its service life. Cards made of polyvinyl chloride have a problem that harmful gas is generated. In the case of landfill treatment, there is a problem that resins such as polyethylene terephthalate and polyvinyl chloride are hardly decomposed in the soil and therefore are not decomposed and remain in the soil or the like. Further, depending on the type of card, for example, a card having a heat-sensitive recording layer, a magnetic recording layer or the like requires record retention of information and glossiness, and since it is often used in a portable manner, the card is resistant to bending and bending. Durability is required. The present invention solves the above problems, and provides a card base material having excellent surface gloss, surface protection, and bending resistance, and which is biodegradable in the natural world.

[0004]

According to the present invention, a card substrate made of a thermoplastic resin is provided with at least a support and a uniaxially or biaxially stretched protective layer laminated on the surface of the support. The present invention relates to the provision of a biodegradable card base material composed of a composition containing a biodegradable resin as a main component. Further, as the support (core layer) made of the biodegradable resin described above,
(A) layer comprising a composition containing a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate (hereinafter referred to as "PHB / V") as a main component, or the copolymer PHB
A layer (B) made of a composition containing / V and caprolactone (hereinafter referred to as "PCL") as main components is used. Also
The protective layer (skin layer) is a layer (B) made of a composition containing PHB / V and PCL as main components, or PCL.
And a layer (C) made of a composition containing a polylactic acid resin (hereinafter referred to as “PLA”) as a main component.

The three-layered sheet according to the present invention includes:
The (B) layer made of a composition containing PHB / V and PCL as the main components and the (A) layer containing PHB / V as the main components,
(B) layer / (A) layer / (B) layer constitution, or (C) layer composed of a composition containing PCL and PLA as main components, and PH
B / V and the (B) layer composed of a composition containing PCL as a main component are characterized by a three-layer structure of (C) layer / (B) layer / (C) layer.

Further, the four-layered sheet according to the present invention comprises a layer (B) composed of a composition containing PHB / V and PCL as main components and a composition containing PHB / V as a main component ( A) layer and PHB / of the same kind or different kind as the (A) layer
(A1) layer composed of V is (B) layer / (A) layer / (A
1) Layer / (B) layer constitution, or (C) layer composed of a composition containing PCL and PLA as main components, PHB / V and PC
A layer (B) composed of a composition containing L as a main component, and (B)
A layer and a (B1) layer composed of the same or different composition,
It is characterized by a four-layer structure of (C) layer / (B) layer / (B1) layer / (C) layer. Further, the protective layer of such a three-layer or four-layer structured base material, for example, the (B) layer and the (C) layer is uniaxially or biaxially stretched and heat-fixed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, as PHB / V constituting the (A) layer used as a support for a card substrate, microorganisms such as hydrogen bacteria Alcaligene are used.
melting point biosynthesized by S. eutrophus is 1
An example is a polyester-based biodegradable resin having a temperature of 0 to 180 ° C. As such a PHB / V, considering the workability,
The content of 3-hydroxyvalerate (PHV) is 1-2.
0 mol% is preferred. If it is less than 1 mol%, it is hard and brittle because of high crystallinity, and tends to be thermally deteriorated during molding due to its high melting point. If it exceeds 20 mol%, the crystallinity and melting point tend to be lowered and the composition tends to soften.

The layer (B) used as a support layer or a protective layer of the card substrate is composed of the above-mentioned composition containing PHB / V and PCL as main components. Such PCL has a melting point of 50 obtained by ring-opening polymerization of ε-caprolactone, which is a cyclic monomer, with an organometallic compound catalyst.
A biodegradable resin having a number average molecular weight of about 1.times.10@4 to 1.times.10@5, which is one type of aliphatic polyester having a temperature of .about.140 DEG C., can be exemplified. The layer (B) according to the present invention is PHB / V.
The stretchability (uniaxial or biaxial stretching) tends to be significantly improved. At this time, the mixing ratio of PCL is 20 to 60% by weight,
It is more preferably 40 to 60% by weight. If it is less than 20% by weight, stretching tends to be difficult, and if it exceeds 60% by weight, it tends to be too soft.

As the layer (C) used as the protective layer of the card base material, the above-mentioned composition containing PCL and PLA as the main components can be used. As PLA, for example, D and L which are biosynthesized by anaerobically fermenting glucose (lactic acid fermentation) using lactic acid bacterium and D of ratcel body
Examples thereof include those obtained by ring-opening polymerization after synthesizing L-, D- and DL-lactide by cyclization reaction of L-form lactic acid. Such PLA has a melting point of 170 to 180 ° C. and is hard and brittle. However, P to PLA
Molding a composition obtained by blending CL tends to impart flexibility and significantly improve strength.
Further, a sheet or the like made of the composition of PCL and PLA tends to have improved heat resistance, solvent resistance, glossiness and the like when uniaxially or biaxially stretched. At this time, the mixing ratio of PCL is preferably 10 to 30% by weight, more preferably 15 to 25% by weight. If the mixing ratio of caprolactone is less than 10% by weight, the sheet tends to become brittle, and if it exceeds 30% by weight, the bending and bending resistance of the card cannot be improved or the heat resistance tends to be poor.

Further, the (A1) layer which is used by laminating on the (A) layer as a support layer of the card base material according to the present invention,
The same or different kind of PHB / V constituting the layer (A), for example, a copolymer of 3-hydroxybutyrate and 4-hydroxybutyrate (3HB / 4HB), 3-hydroxybutyrate and 3-hydroxypropionate. Copolymer (3H
B / 3HP) or the like may be used. Further, the (B1) layer used as a support layer laminated on the (B) layer is the same or different type as the support layer comprising the composition of PHB / V and PCL constituting the (B) layer, for example, PHB / V. Polyglycol resin (PGA) composition, 3HB / 4HB and PCL composition, 3HB / 4HB and PGA composition, 3HB / 3H
A copolymer of P and PCL, a copolymer of 3HB / 3HP and PGA, or the like may be used.

Such (B) layer / (A) layer / (A1) layer /
4-layer structure of (B) layer, or (C) layer / (B) layer / (B
The four-layer constitution of 1) layer / (C) layer is (A) layer or (B)
When it is necessary to print on both sides of the layer, one side of the (A) layer and the (A1) layer or one side of the (B) layer and the (B1) layer is printed without performing the troublesome double-sided printing. May be laminated so as to contact the protective layer. At this time, the PLA layer contributes to printability and surface glossiness (glazing effect), and tends to give beauty to the card, for example, but there is no particular limitation, but it is generally used as a thin card. Target.

Such a biodegradable sheet having a three-layer structure or a four-layer structure can be suitably used as a thick and thin biodegradable card, which is cut into a card shape, for example. Thick ones are, for example, credit cards and cash cards.
For example, it is necessary to retain information, such as a card, is frequently carried, and tends to be suitably used for things that are used for a long period of time. As a thickness constitution, a support layer, for example, a layer (A) is preferably 720 to 560 μm, and a protective layer, for example, a layer (B) is preferably 20 to 100 μm. Further, the thin type is used for items that tend to be used in a relatively short period of time, such as telephone cards and prepaid cards. At this time, the thickness configuration is not particularly limited,
The support layer, for example, the support layer (B) layer has a thickness of 150 to 250 μm,
The protective layer, for example, the layer (C) may have a thickness of 20 to 100 μm.

(B) / (A) / (B) and (B) / (A) / (A1) / (B) or (C) / according to the present invention
(B) / (C) and (C) / (B) / (B1) / (C)
In this state, the biodegradable sheet base material having the constitution has rigidity, but is fragile and easy to tear, and tends to be broken when bent. In order to prevent these drawbacks, such a biodegradable sheet substrate has a protective layer (B) layer or (C) layer of 1
Axial or biaxial stretching is required. The stretching method is not particularly limited, but sequential biaxial stretching is preferable. Furthermore, it is necessary to heat-fix for dimensional stability and curl prevention. The stretching temperature is 40 in the layer (B).
It is preferable that the temperature is ˜60 ° C., the layer (C) has a temperature of 40 ° C. to 80 ° C., and the stretching ratio of the layers (B) and (C) is 3.5 to 4.0 times in each of the length and width. Further, the heat setting temperature is (B) layer, (C)
It can be exemplified that both layers are heat-set at 100 to 130 ° C. for about 25 to 120 seconds.

The method for producing the biodegradable card base material according to the present invention is not particularly limited. For example, a dry lamination method in which a support and a protective layer are laminated via an adhesive, at least two types of sheets, for example, (A) layer and (B) layer or (B) layer and (C) layer are separately produced. Then, a method of laminating by thermocompression bonding can be mentioned.

Among these, the sheets (A) layer, (A1) layer made of PHB / V, and PHB / V and PCL are used.
A sheet (B) layer composed of a composition containing
The layer 1) and the sheet (C) layer composed of a composition containing PCL and PLA as main components are separately produced. Next, (B)
Layer / (A) Layer / (B) Layer, and (B) Layer / (A) Layer /
(A1) layer / (B) layer, or (C) layer / (B) layer /
(C) layer, and (C) layer / (B) layer / (B1) layer /
Thermocompression bonding so as to form the (C) layer, for example, 120 to 1
An example is stacking at 60 ° C. and 10 to 50 kg / cm 2.

PHB / constituting the layer (A) according to the present invention
V, the composition containing PHB / V and PCL as the main constituents of the (B) layer, and the composition containing PCL and PLA as the main constituents of the (C) layer as additives, if desired. Fillers such as heat stabilizers, antioxidants, light stabilizers, antistatic agents, lubricants, pigments or titanium oxide, calcium carbonate, barium sulfate, calcium hydroxide, mica, talc and the like can be added. Further, other thermoplastic resins and the like can be blended as necessary within the range that does not impair biodegradability, and there is no particular limitation.

When a printing layer (thermosensitive recording layer) is provided on the biodegradable laminated sheet according to the present invention, it is provided on the surface or between layers (A) and (B) or (C) of (B). It is preferable. In the case of a magnetic card, it is preferable to form the magnetic layer by an appropriate method before or after cutting the surface of the protective layer into a card shape.

The biodegradable card substrate according to the present invention is a card.
When molded into a card, it has sufficient bending resistance as a card,
Tensile strength, impact strength, stackability, heat resistance, heat stretchability,
It has tack resistance, chemical immersion resistance, moisture resistance, and gloss, and has biodegradability that can be decomposed by microorganisms in the natural world.

[0019]

EXAMPLES The present invention will be described in detail below with reference to examples. However, it goes without saying that the present invention is not limited to the following examples. In the following examples, the measurement of each inspection item was performed by the following method.

[Bending strength (times)]: JIS P-
According to No. 8115. [Tensile strength (kg / cm2)]; JIS X-6301
It was measured according to the No. [Impact strength]: Measured according to JIS X-6301. … The card has cracks, cracks, etc. ×: cracks, cracks, etc. are observed. [Lamination]: Measured according to JIS X-6301. ... No gap is created between the laminated layers. X: A gap is recognized between the stacked layers. [Heat resistance]: Measured according to JIS X-6301. … There is no change on the surface of the card. ×: A change is recognized on the surface of the card. [Heat resistance stretchability]: Measured according to JIS X-6301. ... Shrinkage rate is ± 0.2% or less. X ... Shrinkage exceeds ± 0.2%. [Adhesiveness]: Measured according to JIS X-6301. ... not sticky. X: Adhesiveness is recognized. [Chemical immersion resistance]: Measured according to JIS X-6301. ... Peeling does not occur. ×: Peeling is recognized. [Magnetic characteristics after chemical immersion]: Measured according to JIS X-6301. ○: No change in magnetic properties. X: Magnetic characteristics change. [Moisture resistance]: Measured according to JIS X-6301. … No change in appearance. X: A change in appearance is observed.

Example 1 In order to prepare a biodegradable substrate consisting of (B) layer / (A) layer / (B) layer having a three-layer structure, 3-hydroxyvalerate content of 3- Copolymer of hydroxybutyrate and 3-hydroxyvalerate (PHB / V) 60% by weight
And polycaprolaton with an average molecular weight of 80,000 (PC
L) 40% by weight of the mixture was melted, kneaded, extruded and cooled with a T-die extruder set at a temperature of 170 ° C. to obtain a sheet. Then, the sheet is sequentially biaxially stretched (stretching temperature 40 to
A biaxially stretched (B) layer having a thickness of 70 μm was obtained at 50 ° C. and a stretching ratio of length × width = 3.5 × 3.5). Further, a layer (A) having a thickness of 620 μm and comprising a layer (B) and a copolymer of 3-hydroxyvaributyrate and 3-hydroxyvalerate having a 3-hydroxyvalerate content of 12 mol%. Thermocompression bonding (150 ° C, 20kg / cm2),
(B) / (A) / (B) = 70/620/70 = 760
A μm biodegradable card substrate was molded. Table 1 shows the bending resistance, tensile strength, impact strength, stacking property, heat resistance, heat stretchability, adhesiveness, chemical immersion resistance, change in magnetic properties, and humidity resistance of the card base material. When the card was buried in soil, the weight decreased by about 10% in about 12 months.

[0022]

[Table 1]

Example 2 In order to prepare a biodegradable substrate consisting of (C) layer / (B) layer / (C) layer having a three-layer structure, polycaprolactone (PC) was used.
L) A mixture of 20% by weight and 80% by weight of a polylactic acid resin (PLA) having an average molecular weight of 200,000 was melted, mixed, extruded and cooled by a T-die extruder set at 210 ° C. to obtain a sheet. . Then, the sheet is sequentially biaxially stretched (stretching temperature 5
Thickness 0 to 60 ° C, draw ratio 3.5 x 3.5) 2
A 0 μm layer (C) was obtained. Further, a layer (C) and a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate having a 3-hydroxyvalerate content of 8 mol% (PH
(B / V) 85% by weight and polycaprolactone (PCL) having an average molecular weight of 80,000 15% by weight, and a 210 μm-thick (B) layer is thermocompression bonded (150 ° C., 20 kg).
/ Cm2) and then (C) / (B) / (C) = 20/21
It was molded into a biodegradable card base material of 0/20 = 250 μm. Table 1 shows the bending strength, tensile strength, impact strength, stacking property, heat resistance, heat stretchability, adhesiveness, chemical immersion resistance, magnetic property change, and humidity resistance of the card base material. When the card is buried in the soil, it weighs about 10% in about 6 months.
Had decreased.

Example 3 In order to prepare a biodegradable substrate consisting of (B) layer / (A) layer / (B) layer having a three-layer structure, 3-hydroxyvalerate content of 3- 60% by weight of hydroxybutyrate and 3-hydroxyvalerate copolymer (PHB / V)
And polycaprolactone 4 having an average molecular weight of 80,000
A 40% by weight (PCL) mixture was melted, kneaded, extruded with a T-die extruder set at a temperature of 170 ° C., and cooled to obtain a sheet. Next, the sheet is successively biaxially stretched (stretching temperature 40 to 50 ° C., stretch ratio 3.5 × 3.5) and has a thickness of 2
A (B) layer of 0 μm was obtained. Further, a layer (B) and a copolymer of 3-hydroxy valerate and 3-hydroxy valerate containing 8 mol% of 3-hydroxy valerate (PHB /
(A) layer of V) having a thickness of 210 μm is thermocompression bonded,
(B) / (A) / (B) = 20/210/20 = 250
A μm biodegradable card substrate was molded. Table 1 shows the bending strength, tensile strength, impact strength, stackability, heat resistance, heat stretchability, adhesiveness, chemical immersion resistance, magnetic property change, and humidity resistance of the card base material. When the card was buried in the soil, the weight decreased by about 50% in about 6 months.

Example 4 In order to prepare a biodegradable substrate consisting of (B) layer / (A) layer / (A1) layer / (B) layer having a four-layer structure, the content of 3-hydroxyvalerate was 8%. Copolymer of mol% 3-hydroxybutyrate and 3-hydroxyvalerate (PHB /
V) a mixture of 60% by weight and 40% by weight of polycaprolactone (PCL) having an average molecular weight of 80,000 at a temperature of 1
A sheet was obtained by melting, kneading, extruding and cooling with a T-die extruder set at 70 ° C. Sequentially biaxially stretching the sheet (stretching temperature 40 to 50 ° C., stretching ratio length × width = 3.5 × 3.
A layer (B) having a thickness of 70 μm obtained by the step 5) was obtained. Furthermore,
A layer (B) and a layer (A) having a thickness of 310 μm and composed of a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate having a 3-hydroxyvalerate content of 8 mol% are subjected to thermocompression bonding (150 ° C., 20 kg / cm2) and then (B) /
(A) / (A1) / (B) = 70/310/310/7
A biodegradable sheet base material of 0 μm = 760 μm was molded.
Table 1 shows the bending resistance, tensile strength, impact strength, stackability, heat resistance, heat stretchability, adhesiveness, chemical immersion resistance, change in magnetic properties, and moisture resistance of the card base material. Also, when the card was buried in the soil, it weighed about 4 months and weighed about 4 months.
It was reduced by 0%.

Comparative Examples 1 to 3 90% by weight of a copolymer (PHB / V) of 3-hydroxybutyrate and 3-hydroxyvalerate having a content of 3-hydroxivalylate of 8 mol% and an average molecular weight of 80, 00
A mixture of 10% by weight of polycaprolactone (PCL) of 0 was melted, kneaded and extruded by a T-die extruder set at a temperature of 170 ° C., and then cooled to obtain a biodegradable card substrate having a thickness of 760 μm, 500 μm and 250 μm. Obtained. Table 2 shows the bending resistance, tensile strength, impact strength, stackability, heat resistance, heat stretchability, adhesiveness, chemical immersion resistance and moisture resistance of each card base material.
It was shown to.

[0027]

[Table 2]

[0028]

The card base material according to the present invention, which is provided with a support made of a biodegradable resin and a protective layer made of a biodegradable resin biaxially stretched on both surfaces thereof, is extremely excellent. Bending resistance, tensile strength, impact strength, stackability, heat resistance, heat stretchability, adhesiveness, chemical dipping resistance, moisture resistance and glossiness, and when buried in the ground as waste. , Is decomposed in a relatively short period of time by microorganisms in the natural world.

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Claims (7)

[Claims] 1. A card base material made of a thermoplastic resin, wherein at least a support and a uniaxially or biaxially stretched protective layer laminated on both surfaces of the support are composed mainly of a biodegradable resin. A biodegradable card base material comprising a composition comprising: 2. A support comprising a biodegradable resin, which comprises a copolymer (PHB / V) of 3-hydroxybutyrate and 3-hydroxybutyrate (PHB / V) as a main component, or a layer thereof. Polymer (PHB / V) and polycaprolactone (PC
The biodegradable card base material according to claim 1, wherein the biodegradable card base material is a layer (B) made of a composition containing L) as a main component. 3. The protective layer made of biodegradable resin is PHB.
/ B and a layer (B) composed of a composition containing PCL as a main component,
Alternatively, the layer (C) is composed of a composition containing PCL and a polylactic acid resin (PLA) as main components.
The biodegradable card substrate according to any one of 1. 4. A (B) layer / (A) layer comprising a PHB / V, a (B) layer composed of a composition containing PCL as a main component, and a (A) layer containing PHB / V as a main component. The biodegradable car according to any one of claims 1 to 3, which has a three-layer structure of / (B) layer.
Substrate. 5. A (C) layer composed of a composition containing PCL and PLA as main components and a (B) layer composed of a composition containing PHB / V and PCL as main components are (C) layer / ( B) layer /
The biodegradable card substrate according to any one of claims 1 to 3, which has a three-layer structure of layer (C). 6. A (B) layer composed of a composition containing PHB / V and PCL as main components, an (A) layer containing PHB / V as a main component, and a PHB of the same kind or different kind as the (A) layer. / V
(A1) layer consisting of (B) layer / (A) layer / (A
The biodegradable card substrate according to any one of claims 1 to 3, which has a four-layer structure of 1) layer / (B) layer. 7. A (C) layer composed of a composition containing PCL and PLA as main components, a (B) layer composed of a composition containing PHB / V and PCL as main components, and the (B) layer. And (B1) layer composed of the same or different composition, (C) layer /
The biodegradable card substrate according to any one of claims 1 to 3, which has a four-layer structure of (B) layer / (B1) layer / (C) layer.