JP2003147264A - Heat seal lacquer composition - Google Patents

Abstract

(57) [Problem] To provide a heat seal lacquer composition having excellent transparency, applicability, heat seal strength, and blocking resistance, and at the same time, having excellent biodegradability. A biodegradable material having excellent transparency, heat seal strength, and blocking resistance, including, as constituents, a base material and a biodegradable coating film using a biodegradable heat seal lacquer composition applied to the upper surface thereof. Provide a complex. A biodegradable heat seal lacquer composition comprising a polyhydroxy acid-based polyester (A) containing a sulfonate structure in a molecule, an antiblocking agent (B), and a solvent (E). .

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to biodegradable heat seal lacquer compositions. More specifically, the present invention relates to a biodegradable heat seal lacquer composition containing a biodegradable polyester and a solvent.

The present invention also relates to a biodegradable composite body comprising a biodegradable substrate and a biodegradable coating film using the biodegradable heat-seal lacquer composition applied on the upper surface thereof as constituent elements. .

[0003]

2. Description of the Related Art In recent years, a drastic increase in the amount of waste has become a major environmental problem. In addition, plastic products account for a large amount of household waste and industrial waste. Therefore, general plastic products have been pointed out as extremely difficult-to-process and environmentally-friendly materials because of their semi-permanently non-degradable properties. Due to such social needs, development of biodegradable plastics that use natural materials or biodegradable synthetic materials and that can be naturally decomposed by microorganisms in the soil is currently being actively pursued.

Further, in recent years, the proliferation of biodegradable material products covered with plastics has become a big environmental problem.
Paper that should have biodegradability, biodegradable fiber cloth,
This is because biodegradable materials such as biodegradable nonwoven fabric and wood are not biodegradable as a result of being covered with plastics. Therefore, not only biodegradable plastics, but also composites of biodegradable materials and biodegradable plastics are being actively developed at present.

Among the biodegradable plastics, polylactic acid is most promising in terms of cost and physical properties, and is highly expected as a transparent thermoplastic resin.

[0006] Since polylactic acid has a low calorific value of less than half that of polyethylene, it does not burden the incinerator even when incinerated and does not generate toxic gas. In addition, polylactic acid spontaneously undergoes hydrolysis in soil or water, and is subsequently decomposed by microorganisms to become a harmless substance. In addition, polylactic acid has a feature that it has a high melting point of around 170 ° C. to 180 ° C. and is excellent in transparency. However, polylactic acid also has drawbacks such as poor elongation and flexibility and low impact resistance due to its rigid molecular structure.

[0007] For the purpose of improving such drawbacks of polylactic acid, by blending or copolymerizing polylactic acid with an aliphatic polyester other than polylactic acid, excellent flexibility and
Many biodegradable plastics with excellent impact resistance have been developed.

The most familiar example is Japanese Patent Laid-Open No. 2001-1.
23055, JP 2001-122289 A, JP 2001-122288 A, JP 2001
As disclosed in JP-A-123371, JP 2001-114997 A, JP 2001-31853 A, etc., a biodegradable film using a polylactic acid-based film or the like is also used for a packaging film or the like. Is beginning to be used.

In such a packaging film, in general, a heat seal adhesive composition is often applied to the surface of the packaging film for the purpose of imparting heat sealability. Here, the heat-sealing property refers to a property of adhering under a high temperature condition, and the heat-sealing adhesive composition refers to an adhesive composition having a heat-sealing property.

Further, the heat seal adhesive composition contains
Non-solution types include hot melt adhesive compositions. The hot-melt adhesive composition has a property that it is solid at room temperature and melts by heating, and the adhesion is completed in a short time only by coating and cooling the base material. The reason why the bonding can be completed by pressing for a short time after the application of the hot-melt adhesive composition is that the hot-melt adhesive composition does not contain water, a solvent or the like and does not require a drying time or a drying device.

As a method for applying the hot melt adhesive composition to the substrate, a hot melt coater method is generally used. Alternatively, the base materials may be directly bonded to each other using a hot melt adhesive composition by an extrusion lamination method using an extruder.

The heat seal adhesive composition also includes a heat seal lacquer composition as a solution type. The heat-seal lacquer composition is generally a liquid at room temperature, and has the property that the adhesion is completed in a short time by applying heat to the base material after drying the base material and further pressing the base material thereon. The heat-seal lacquer composition generally requires a drying step because it contains a solvent, but has the advantage that the application step is simple because it does not require heating during application to the substrate.

As a method of applying the heat-seal lacquer composition to the substrate, a gravure coater method, a roll coater method, a bar coater method, etc. are used. The present invention relates to this solution type heat seal lacquer composition.

Here, conventionally used resins for hot melt adhesive compositions or heat seal lacquer compositions are urethane polymers, acrylic polymers,
It is a non-biodegradable resin such as aromatic polyester. Therefore, when a hot melt adhesive composition or a heat seal lacquer composition containing the above resin component is applied to a biodegradable film, there is a problem that the biodegradable material cannot be fully utilized. Further, the resin for hot-melt adhesive composition or heat-seal lacquer composition is often applied on a transparent film-shaped substrate, and therefore preferably has transparency. Therefore, development of a transparent hot-melt adhesive composition having biodegradability or a transparent heat-seal lacquer composition having biodegradability has been awaited.

Based on the above situation, research and development of biodegradable hot-melt adhesive compositions or heat-seal lacquer compositions are currently being actively carried out in various fields. For example, US Pat. No. 5,169,889 discloses a hot-melt adhesive composition obtained by combining a polyester resin containing 3-hydroxybutyric acid and hydroxypentanoic acid (trade name: Biopol, manufactured by Seneca). However, since the resin used in the biodegradable hot melt adhesive composition contains a non-biodegradable substance in the resin mixture, it is not completely biodegradable and has the property of being hard and brittle. However, it cannot be suitably used as a binder of a biodegradable hot melt adhesive composition or a biodegradable heat seal lacquer composition.

Further, Japanese Patent Application Laid-Open No. 57-150393,
JP-A-59-220192 and JP-A-5-1057.
36, JP-A-5-148352, JP-A-5
A biodegradable plastic that is biodegradable by microorganisms in the soil, such as disclosed in Japanese Patent Publication No. 179016, has been developed. Specific product names include Bionore (manufactured by Showa High Polymer Co., Ltd.), Lacty (manufactured by Shimadzu Corporation), Matterby (manufactured by Novamont), Novon, Deglaster (manufactured by Ecostar), and the like. However, since the biodegradable resin is generally insoluble in general-purpose solvents, it is difficult to use it for applications other than melt molding such as injection molding, and a biodegradable hot melt adhesive composition, or When it is used as a binder of a heat seal lacquer composition, the adhesive strength is not at a sufficiently satisfactory level.

Further, Japanese Patent Laid-Open No. 5-339557 discloses a hot melt adhesive composition using polylactic acid or a lactic acid copolymer resin derived from lactic acid and another hydroxydicarboxylic acid. However, the resin used in the biodegradable hot melt adhesive composition is sufficiently satisfactory in solubility and adhesiveness for suitable application as a binder of the biodegradable heat seal lacquer composition. Not a standard.

JP-A-5-339557 discloses a hot melt adhesive composition which is obtained by modifying polylactic acid having a molecular weight of 10,000 or more with a diisocyanate compound and is excellent in alkaline water disintegration and biodegradability. ing.
However, the resin used in the above-mentioned biodegradable hot melt adhesive composition is not at a sufficiently satisfactory level in terms of adhesiveness to be suitably used as a binder of the biodegradable heat seal lacquer composition. .

Further, JP-A-8-81897 discloses a polyester adhesive composition containing 65 to 95 mol% of lactic acid residues and modified with caprolactone, oxyacid, succinic acid, propylene glycol and glycerin. Has been done. However, the resin used in the above biodegradable polyester adhesive composition is also suitable for use as a binder of a biodegradable hot melt adhesive composition or a biodegradable heat seal lacquer composition. In terms of sex, it is not at a satisfactory level.

Further, in JP-A-10-251612, an aliphatic dicarboxylic acid or its acid anhydride or its diester and an aliphatic dicarboxylic acid having an alkyl group or an alkenyl group in its side chain or its acid anhydride or A hot-melt adhesive composition using an aliphatic polyester produced by polycondensing the diester and an aliphatic glycol is disclosed. But,
The resin used in the biodegradable hot-melt adhesive composition is suitable for use as a binder of the biodegradable heat-seal lacquer composition, at a sufficiently satisfactory level in terms of solubility and adhesiveness. Absent.

Further, Japanese Patent Application Laid-Open No. 7-278510 discloses a biodegradable hot melt adhesive composition comprising raw rosin, natural rubber and a vegetable or mineral wax. However, the resin used in the biodegradable hot melt adhesive composition is also preferably used as a binder of the biodegradable heat-seal lacquer composition in terms of transparency, solubility and adhesiveness. Is not at a satisfactory level.

Further, in Japanese Patent Application Laid-Open No. 8-92359, a polylactic acid type biodegradable polyester resin is used.
A biodegradable adhesive composition that can be used as a hot melt adhesive composition is disclosed. However, the resin used in the above biodegradable adhesive composition is not sufficiently satisfactory in terms of blocking resistance in order to be suitably used as a binder of a biodegradable heat seal lacquer composition.

As described above, the properties required for the binder resin of the biodegradable hot melt adhesive composition and the properties required for the binder resin of the biodegradable heat seal lacquer composition do not necessarily match. Therefore, at present, a biodegradable heat-seal lacquer composition which is sufficiently satisfactory in transparency, coating property, heat-sealing strength, and blocking resistance has not yet been obtained.

[0024]

Based on the above situation,
An object of the present invention is to provide a heat-seal lacquer composition having excellent transparency, coating property, heat-sealing strength and blocking resistance, and at the same time having excellent biodegradability. Another object of the present invention is to provide a biodegradable substrate and a biodegradable coating film using the biodegradable heat-seal lacquer composition applied on the upper surface thereof as constituent elements, which has excellent transparency. And to provide a biodegradable composite having heat seal strength and blocking resistance.

[0025]

The present invention provides the following formula (1):
And / or a polyhydroxy acid-based polyester (A) containing a sulfonate structure represented by the formula (2) in the molecule,
A biodegradable heat seal lacquer composition comprising an antiblocking agent (B) and a solvent (D).

[0026]

[Chemical 5] (In the formula (1), X is an alkyl group having 20 or less carbon atoms, a cycloalkyl group, an aryl group, an arylalkyl group or hydrogen, a hydroxyl group, a nitro group, an amino group, an acyl group, a sulfonic acid group, an alkoxyl group and a halogen. And M is lithium, sodium, potassium or an amine represented by the following formula (3), m1 is an integer of 0 to 3, m2 is an integer of 1 to 4, and m1 + m2
Satisfies the relationship of 1 ≦ m1 + m2 ≦ 4. N1 represents an integer of 1 or more. )

[0027]

[Chemical 6] (In the formula (2), R1 represents an alkylidene group having 20 or less carbon atoms, and M represents lithium, sodium, potassium or an amine represented by the following formula (3))

[0028]

[Chemical 7]

(In the formula (3), R2, R3, R4 and R5 each independently represent hydrogen, an alkyl group, a phenyl group or a benzyl group.) Further, the sulfonate structure represented by the above formula (1). Is a sulfonate structure represented by the following formula (4), which is the above-mentioned biodegradable heat seal lacquer composition.

[0030]

[Chemical 8] (In the formula (4), R2, R3, R4 and R5 each independently represent hydrogen, an alkyl group, a phenyl group or a benzyl group.)

The above-mentioned biodegradable heat-seal lacquer composition characterized in that the anti-blocking agent contains wax (C).

The anti-blocking agent is an inorganic particle (D)
The biodegradable heat-seal lacquer composition described above.

The above biodegradable heat seal lacquer composition is characterized in that the sulfonate group is contained in the polyhydroxy acid polyester (A) in a concentration range of ⁵ to 100 eq / 10 ⁶ g. .

The above-mentioned biodegradable heat seal lacquer composition is characterized in that the polyhydroxy acid type polyester (A) contains 80 mol% or more of lactic acid residues.

Polyhydroxy acid type polyester (A)
Is an L-lactic acid residue and a D-lactic acid residue, and has an L / D molar ratio of 1 to 9, which is the above-mentioned biodegradable heat-seal lacquer composition.

A biodegradable composite comprising as its constituents a degradable substrate and a biodegradable coating film using the biodegradable heat-seal lacquer composition described above, which is applied to the upper surface of the degradable substrate.

As the biodegradable substrate, a biodegradable film,
The above-mentioned biodegradable composite, which comprises, as a constituent, one or more kinds selected from the group consisting of biodegradable plastic, paper, biodegradable fiber cloth, biodegradable nonwoven fabric, and wood.

[0038] The above-mentioned biodegradable composite, which comprises a polylactic acid-based film as a constituent element as the biodegradable substrate.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-seal lacquer composition according to the present invention comprises a polyhydroxy acid-based polyester (A) containing a sulfonate structure of the formula (1) and / or the formula (2) in the main chain, and an anti-blocking agent. Agent (B) and solvent (D)
And, including. First, the polyhydroxy acid type polyester (A) [may be simply referred to as polyester (A) hereinafter] will be described.

The sulfonate-containing structure represented by the formula (1) has the following structure.

[Chemical 9]

In the formula (1), X is an alkyl group having 20 or less carbon atoms, a cycloalkyl group, an aryl group, an arylalkyl group, hydrogen, a hydroxyl group, a nitro group, an amino group, an acyl group, a sulfonic acid group or an alkoxyl group. And halogen, and M represents lithium, sodium, potassium, or an amine represented by the following formula (3). Among these, M is preferably lithium, sodium or potassium from the viewpoint of dispersion stability of the anti-blocking agent and the like.

In the formula (1), _m1 in (X) m1
Is the number of bonds to the aromatic ring of X, which represents the above substituent, and m1 is an integer of 0 to 3. In addition, (SO ₃ M) _m2
M2 in is the number of bonds to the aromatic ring of SO ₃ M representing a sulfonate, m2 is an integer of 1 to 4,
m1 + m2 satisfies the relationship of 1 ≦ m1 + m2 ≦ 4. N1 represents an integer of 1 or more.

Here, two or more substituents represented by X can be bonded to one aromatic ring. In this case, the substituent represented by X, which is bonded, may have two or more kinds of different structures, or may have only one kind of structure. The same applies to the sulfonate represented by SO ₃ M.

If the sulfonate-containing structure represented by the above formula (1) is contained in the polyester (A) regardless of the main chain or side chain of the molecular chain of the polyester (A). Often, other main constituents include a residue of hydroxy acid described later.

That is, the sulfonate-containing structure represented by the above formula (1) is located between the molecular chains of the polyester (A) and / or at the molecular chain terminals. Therefore, when the structure is located between the molecular chains, C of the other sulfonate-containing structure represented by the above formula (1) or (4).
Both of the OO- groups are bound to the hydroxy acid residue described below, and when the structure is located at the terminal of the molecular chain, one of the COO- groups is the hydroxy acid residue described below and the COO- group. The other side is bonded to hydrogen, an alkyl group, a hydroxyalkyl group and the like.

The sulfonate-containing structure represented by the formula (2) has the following structure.

[Chemical 10]

R1 represents an alkylidene group having 20 or less carbon atoms, and M represents lithium, sodium, potassium, or an amine represented by the following formula (3). In the formula (2), M is preferably lithium, sodium or potassium from the viewpoint of dispersibility of the antiblocking agent and the like.

Here, the sulfonate-containing structure represented by the formula (2) is bound to the end of the molecular chain of one polyester (A), and may be contained at one or both ends of the molecular chain.

It is sufficient that the molecular chain of the polyester (A) used in the present invention contains either one of the sulfonate-containing structures represented by the above formula (1) or (2). The structure of may be contained.

The amine represented by the formula (3) has the following structure.

[Chemical 11] In the formula (3), R2, R3, R4, and R5 each independently represent hydrogen, an alkyl group, a phenyl group, or a benzyl group.

In the equation (3), R2, R3, R
4 and R5 can each independently select the kind of the substituent, and R2, R3, R4 and R5 each may represent the same substituent as the other substituents or represent different substituents. May be. The amine represented by the formula (3) may have two or more different structures in one polyester (A), or may have only one kind of structure.

Further, the polyester (A) used in the present invention preferably contains a sulfonate-containing structure represented by the following (4).

[Chemical 12] In the formula (4), M represents lithium, sodium, potassium, or the amine represented by the formula (3). N2 represents an integer of 1 or more. M is preferably lithium, sodium or potassium from the viewpoint of dispersibility of the antiblocking agent and the like.

If the sulfonic acid group-containing structure represented by the above formula (4) is contained in the polyester (A) regardless of the main chain or side chain of the molecular chain of the polyester (A). Often, other main constituents include a residue of hydroxy acid described later.

That is, the sulfonate-containing structure represented by the above formula (4) is located between the molecular chains of the polyester (A) and / or at the molecular chain terminals. Therefore, when the structure is located between the molecular chains, C of the other sulfonate-containing structure represented by the above formula (1) or (4).
Both of the OO- groups are bonded to the hydroxy acid residue described below, and when the structure is located at the end of the molecular chain, one of the COO- groups is a hydroxy acid residue described below and a COO- group. The other is bonded to hydrogen, an alkyl group, a hydroxyalkyl group and the like.

(Production Method of Polyester (A)) The polyester (A) used in the present invention is prepared by copolymerizing a sulfonate-containing compound represented by the following formula (5) with a hydroxy acid described below. It is a manufactured polyester.

[0056]

[Chemical 13]

In the formula (5), R6 and R7 each independently represent hydrogen, an alkyl group or a hydroxyalkyl group, and M represents lithium, sodium, potassium or the amine represented by the formula (2). In the formula (6), M is preferably lithium, sodium or potassium from the viewpoint of dispersibility of the ink pigment.

In the formula (5), the types of R6 and R7 can be independently selected, and R6 and R7 may be the same or different. Here, it is preferable to copolymerize using a sulfonate-containing compound represented by the following formula (6).

[0059]

[Chemical 14]

In the formula (6), R6 and R7 each independently represent hydrogen, an alkyl group or a hydroxyalkyl group, and M represents lithium, sodium, potassium or the amine represented by the formula (3). . Also, n2
Represents an integer of 1 or more. From the viewpoint of dispersibility of the ink pigment, M is preferably lithium, sodium or potassium.

The sulfonate-containing compound represented by the above formula (5) or (6) can be copolymerized not only in one kind but also in two kinds.

The polyhydroxy acid type polyester of the present invention has 60 hydroxy acid components in all components (polycarboxylic acid component, polyol component, hydroxy acid component).
It is a polyester composed of at least 70 mol%, and the hydroxy acid component is preferably at least 70 mol%, more preferably 80 mol%.
It is at least mol%.

The hydroxy acid copolymerized in the present invention is a compound having an alcoholic hydroxy group and a carboxyl group in one molecule. Examples of hydroxy acids include glycolic acid, 2-hydroxybutyric acid, and 3 in addition to the above-mentioned lactic acid.
-Hydroxybutyric acid, 4-hydroxybutyric acid, 16-hydroxyhexadecanoic acid, 2-hydroxy2-methylbutyric acid,
10-hydroxystearic acid, malic acid, citric acid,
Gluconic acid or the like is used. Further, an intramolecular ester of a hydroxy acid such as caprolactone and a cyclic ester formed by losing a water molecule from an α-hydroxy acid such as lactide are also used. These can use 1 type (s) or 2 or more types.

Components other than the hydroxy acid include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid, ethylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, 1,6- Hexanediol, diol such as 1,4-cyclohexanedimethanol, and the like can be used within a range that does not significantly impair biodegradability. Note that aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and aromatic diols such as bisphenol-A and alkylene oxide adducts of bisphenol-A may be copolymerized in a small amount. .

Polyglycerin may be copolymerized with the polyester (A).

The degree of polymerization of the polyglycerin segment is 3 to.
It is preferably in the range of 20 and particularly preferably 4 to
The range is 15. If the degree of polymerization is 2 or less, the reactivity with the polyfunctional isocyanate described below tends to decrease,
If the degree of polymerization exceeds 20, the water resistance of the coating film may decrease.

The proportion of the polyglycerin segment in the polyhydroxy acid type ester (A) is from 0.01 to
The range of 10% by weight is preferable, the range of 0.1-5% by weight is more preferable, and the range of 0.2-3 is most preferable.

As the method for producing the polyester (A),
There is no particular limitation, and a conventionally known method can be used. For example, lactide, which is a dimer of lactic acid, and the sulfonate compound having a hydroxyl group are melt-mixed and heated using a known ring-opening polymerization catalyst (eg, tin octylate, aluminum acetylacetonate). Examples thereof include a method of ring-opening polymerization and a method of performing direct dehydration polycondensation by heating and reducing pressure. The polyester (A) used in the present invention is obtained by adding the compound for introducing the sulfonate represented by the formula (3) or the formula (4) between the start of polymerization and the end of the polymerization. To be

(Composition of Polyester (A)) The polyester (A) contains 5 to 100 e of the sulfonate.
It is preferably contained in the concentration range of q / 10 ⁶ g.
When it is 5 equivalents / 10 ⁶ g or less, strong adhesiveness may not be obtained. Further, if it exceeds 100 equivalent / 10 ⁶ g, a biodegradable heat seal lacquer having good biodegradability and water resistance may not be obtained. If the sulfonate group is 5 equivalent / 10 ⁶ g or more in the polylactic acid, the hydroxy acid (copolymerization component) other than lactic acid is 0%.
But it's okay.

When the above polyester (A) is a lactic acid type polyester, it is preferable that the total lactic acid residue in the hydroxy acid is 80 mol% or more, and more preferably,
It is 90 mol% or more, and more preferably 95 mol% or more. If it is less than 80 mol%, good biodegradability and coating film physical properties may not be obtained. Further, from the viewpoint of mass, it is preferable that the lactic acid residue is contained in an amount of 90% by mass or more, and further preferably 95% by mass or more,
Most preferably, it contains 97 mass% or more.

As lactic acid, any of L-lactic acid, D-lactic acid and DL-lactic acid can be used.

The molar ratio of L-lactic acid and D-lactic acid (L / L
D) is preferably 1 to 9 from the viewpoint of solvent solubility, and more preferably 1 to 5.6. When L / D is more than 9, the solubility of the polyester (A) in the solvent used may be poor, and the polyester may not be properly used as a binder for heat seal lacquer. When L / D is less than 1 (D-lactic acid excess), it tends to be difficult to manufacture at low cost.

(Physical Properties of Polyester (A)) The reduced viscosity of the polyester (A) is preferably in the range of 0.3 to 1.5 dl / g. Reduced viscosity is 0.3 dl / g
If it is lower than the above range, cissing may be caused during printing, and if the reduced viscosity is too high, the viscosity of the heat-seal lacquer composition may increase, and good printability may not be obtained.

The reduced viscosity is measured at a sample concentration of 0.
It is a value measured using an Ubbelohde viscous tube at 125 g / 25 ml, a measurement solvent chloroform, and a measurement temperature of 25 ° C.

The glass transition temperature Tg of the polyhydroxy acid polyester (A) is preferably 35 to 60 ° C. More preferably, it is 40 to 55 ° C. 35-60
Within the range of 0 ° C, good adhesion strength to the biodegradable film and good blocking resistance can be obtained.

The polyester (A) thus obtained is preferably biodegradable. Here, the term "biodegradable" refers to the property of being converted into a low molecular weight compound by the metabolism of organisms in the process of decomposition.

The glass transition point Tg can be adjusted, for example, by changing the ratio of the copolymerization component of the polyester (A). The Tg is a value measured by the DSC (differential scanning calorimeter) method.

Next, the biodegradable heat seal lacquer composition of the present invention will be described. The biodegradable heat seal lacquer composition of the present invention further contains a solvent as the E component. The solvents commonly used in heat seal lacquer compositions can be used. Specific examples include toluene, aromatic hydrocarbon solvents such as xylene, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate,
Ester solvent such as isobutyl acetate, ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, alcohol solvent such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, ethylene glycol monomethyl Examples thereof include glycol ether solvents such as ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether, and glycol ether ester solvents which are acetylated products of the above glycol ethers. The above solvents may be used alone or in combination of two or more.

Further, in the biodegradable heat seal lacquer composition of the present invention, the amount of the above components is 100 to 100 parts by weight of the polyester (A) and 100 to 100 parts by weight of the solvent (D).
It is preferably in the range of 2000 parts by weight. If the compounding amount of the solvent (D) is less than 100 parts by weight, the viscosity of the heat-sealing lacquer tends to be too high, and the suitability for coating tends to decrease. If it exceeds 2000 parts by weight, the dry film thickness is insufficient. However, there may arise a problem that the performance as the heat seal lacquer cannot be exhibited.

<< Explanation of Antiblocking Agent Used in the Present Invention >> Next, the antiblocking agent (B) used in the present invention will be explained by adding the antiblocking agent (B). Various things are used if they are things. Representative examples include oils, waxes, organic particles, inorganic particles and the like. Among these, waxes and inorganic particles are preferable. Polyester (A) used in the present invention
Thereby, waxes and particles can be stably dispersed in a mixture of solvents.

The wax (C) is not particularly limited as long as it has a function as a wax. Examples of the wax include various synthetic waxes and natural product waxes, and those having biodegradability are preferable. Conventionally known natural waxes such as plant waxes and animal waxes, biodegradable synthetic waxes, and the like can be used.

Specific examples of the wax (C) include hydrocarbon waxes such as liquid paraffin, natural paraffin, microwax, synthetic paraffin and polyethylene wax, fatty acid waxes such as stearic acid, stearic acid amide and palmitin. Fatty acid amide wax such as acid amide, methylene bis stearamide, ethylene bis stearamide, oleic acid amide, and esyl acid amide, lower alcohol ester of fatty acid, polyhydric alcohol ester of fatty acid, fatty acid polyglycol ester, etc. Ester wax, alcohol wax such as cetyl alcohol, stearyl alcohol, natural wax such as olefin wax, castor wax, carnauba wax, gold derived from fatty acid having 12 to 30 carbon atoms Such as soaps, and the like.

Here, specific examples of the biodegradable wax include plant waxes such as carnauba wax, castor wax, candelia wax and montan wax, animal waxes such as beeswax, and hydrocarbon waxes such as natural paraffin. , Fatty acid waxes such as stearic acid, stearic acid amide, palmitic acid amide, methylene bis stearoamide, ethylene bis stearoamide, oleic acid amide, esyl acid amide, etc., fatty acid amide waxes, lower alcohol esters of fatty acids ,
Examples thereof include ester waxes such as polyhydric alcohol esters of fatty acids and fatty acid polyglycol esters, alcohol waxes such as cetyl alcohol and stearyl alcohol, and metal soaps derived from fatty acids having 12 to 30 carbon atoms.

From the viewpoint of stability of quality, synthetic waxes are preferable, but among the above-mentioned biodegradable waxes, natural waxes such as plant waxes and animal waxes which are particularly excellent in biodegradability are also preferable. Further, among the above-mentioned natural waxes, plant waxes such as carnauba wax and castor wax are most preferable from the viewpoint of easy availability and cost.

Further, the above-mentioned biodegradable wax may contain impurities to the extent that its characteristics are not impaired.

The wax (C) serves as an anti-blocking agent in the biodegradable heat seal lacquer composition of the present invention.

Further, the above wax (C) is not limited to one type among vegetable wax, animal wax, biodegradable synthetic wax and the like, and two or more types may be used in combination. It is also preferable to use a biodegradable wax and a biodegradable wax together.

The melting point of the wax (C) is 6
It is preferably in the range of 0 to 130 ° C., and 70 to 12
More preferably, it is in the range of 0 ° C, and most preferably in the range of 80 to 100 ° C. If the melting point is less than 60 ° C,
Blocking tends to occur easily over time or in an environment of high temperature. On the other hand, if the melting point exceeds 130 ° C, the biodegradability tends to decrease.

The number average molecular weight of the wax (B) is preferably in the range of 200 to 2000, more preferably in the range of 300 to 1500,
Most preferably, it is in the range of 400 to 1000. When the number average molecular weight is less than 200, sufficient blocking resistance tends not to be obtained. On the other hand, when the number average molecular weight exceeds 2000, the biodegradability of the biodegradable wax tends to decrease.

The amount of the wax (C) is preferably in the range of 0.1 to 50 parts by mass with respect to 100 parts by mass of the polyester (A). The blending amount is 0.1
If it is less than 10 parts by mass, the blocking resistance tends to be insufficient, and if the amount is more than 50 parts by mass, there is a problem that the sealing strength is lowered.

Specific examples of the inorganic particles (D) include oxides, hydroxides, sulfates and carbonates of metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony and titanium. Silicate,
Inorganic particles containing, for example, are included. More detailed specific examples include silica gel, aluminum oxide, calcium hydroxide, calcium carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, zinc oxide, lead oxide, diatomaceous earth, zeolite, aluminosilicate, talc, white carbon, mica. , Glass fiber, glass powder, glass beads, clay, wollastonite, iron oxide, antimony oxide, titanium oxide, lithopone, pumice powder, aluminum sulfate, zirconium silicate, barium carbonate, dolomite, molybdenum disulfide, iron sand, carbon black,
Inorganic particles containing, for example, are included.

Among the inorganic particles, silica gel particles are particularly preferable from the viewpoint of environmental load in soil. Further, the inorganic particles (D) may contain impurities to the extent that their characteristics are not impaired. Also, the shape of the particles is
It may have any shape such as powder, granules, granules, flat plate, fibrous shape and the like.

Specific examples of the organic particles include polymers such as polymethylmethacrylate resin, polystyrene resin, nylon resin, melamine resin, guanamine resin, phenol resin, urea resin, silicone resin, methacrylate resin and acrylate resin. Particles, or cellulose powder, nitrocellulose powder,
Examples include wood, waste paper powder, chaff powder, starch, and the like.

The polymer particles can be obtained by a polymerization method such as an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a soap-free polymerization method, a seed polymerization method and a micro suspension polymerization method. Further, the organic particles may contain impurities to the extent that their characteristics are not impaired. In addition, the shape of the particles may be any shape such as powder, granules, granules, flat plates, and fibrous shapes.

Further, the anti-blocking agent (B)
As the above, not only one kind of the inorganic particles, organic particles, waxes, etc., but also two or more kinds may be used in combination. It is also preferable to use the wax (C) and particles in combination, and the biodegradable wax and inorganic particles (D), especially silica gel may be used in combination.

When the antiblocking agent (B) is inorganic particles or organic particles, the lower limit of the average particle diameter of the particles is preferably 1.0 μm, and 1.5 μm.
m is more preferable, and 2.0 μm is most preferable. The upper limit of the average particle size of the particles is 12.0.
The thickness is preferably μm, more preferably 10.0 μm, still more preferably 8.0 μm. If the average particle size is less than 1.0 μm, the effect of improving the blocking resistance becomes small, and the particles tend to aggregate.
On the other hand, if the average particle size exceeds 12.0 μm, the transparency and smoothness of the coating film may be impaired and the coating film appearance may be poor.

When the antiblocking agent (B) is inorganic pox, the lower limit of the specific surface area of the particles is 50 m.
It is preferably ² / g, more preferably if 80 m ² / g, is most preferable 100 m ² / g.
The upper limit of the specific surface area of the particles is preferably 700 m ² / g, more preferably 600 m ² / g, most preferably 500 m ² / g. If the specific surface area is less than 50 m ² / g, or if the specific surface area exceeds 700 m ² / g, the transparency of the coating film may deteriorate.

The amount of the anti-blocking agent (B) added was 100 parts by weight with respect to 100 parts by weight of the polyester (A).
It is preferably in the range of 1 to 50 parts by mass. When the blending amount is less than 0.1 parts by mass, the blocking resistance becomes insufficient, and when the blending amount exceeds 50 parts by mass, there is a problem that the heat seal strength is lowered. When the antiblocking agent is organic or inorganic particles, the amount is preferably 30 parts by mass or less.

<< Other Components >> The biodegradable heat-seal lacquer composition of the present invention may contain, if necessary, for example, an antioxidant, a heat stabilizer, an ultraviolet absorber, a lubricant, a tackifier, a plasticizer. , Cross-linking agent, viscosity modifier, antistatic agent,
Various additives such as a fragrance, an antibacterial agent, an antifoaming agent, a dispersant, and a polymerization inhibitor can be added within a range that does not impair the effects of the present invention.

<< Method for Producing Biodegradable Heat Seal Lacquer Composition of the Present Invention >> Next, a method for producing the biodegradable heat seal lacquer composition according to the present invention will be described.

The method for producing the biodegradable heat-seal lacquer composition of the present invention is not particularly limited as long as it is a conventionally known method. For example, the biodegradable polyester (A) is dissolved in the solvent (E), the anti-blocking agent (B) is added thereto, and the mixture is dispersed using a ball mill, a paint shaker, or the like to obtain the biodegradable property according to the present invention. Heat seal lacquer compositions can be produced.

<Biodegradable Complex of the Present Invention> Next, the biodegradable complex of the present invention will be described.

The biodegradable composite according to the present invention comprises a biodegradable substrate and a biodegradable coating film using the biodegradable heat seal lacquer composition according to the present invention, which is applied to the upper surface of the biodegradable substrate. Include as an element.

As the biodegradable substrate, any substrate can be used as long as it has biodegradability and can be coated with the biodegradable heat seal lacquer composition.

The biodegradable base material is preferably in the form of a sheet, but it is not limited to the sheet form, and it is possible to apply a biodegradable heat-seal lacquer composition to a certain wide range. As long as it has a flat surface, it can be applied to one having a three-dimensional shape. In addition, the surface having the certain width may be a curved surface or may have irregularities.

As the biodegradable substrate, for example, biodegradable film, biodegradable plastic, paper, biodegradable fiber cloth, biodegradable nonwoven fabric, wood, etc. can be used. Further, as the biodegradable substrate in the present invention, a polylactic acid-based film, and paper containing pulp as a main component,
Particularly preferred.

As the polylactic acid type film, poly L-lactic acid type film is particularly preferable. Also,
As the paper containing the pulp as a main component, grading, medium quality paper,
High quality paper, paperboard such as cardboard, and the like are particularly preferable.

Further, the polylactic acid-based film may be processed so that the biodegradable heat-seal lacquer composition is more receptive. For example, (i) a polylactic acid-based film is foamed to form a large number of fine holes, and the acceptability of the biodegradable ink composition is improved by the fine holes, and (ii) a solvent-soluble fine powder is mixed. The fine powder was dissolved and removed from the formed plastic film with a solvent, and the fine powder existing site thus removed was made into fine pores, and the fine pores improved the receptivity of the biodegradable heat-seal lacquer composition. Thing or (ii
i) A plastic film formed by mixing fine powder is stretched, and this stretching causes fine cracks between the fine powder and the plastic, and the fine cracks allow the biodegradable heat-seal lacquer composition to be received. Those having improved properties can be suitably used.

The method for applying the biodegradable heat-seal lacquer composition according to the present invention is not particularly limited, and a conventionally known method can be used. For example, silk screen printing method, offset printing method, letterpress printing method, gravure printing method, gravure offset printing method, flexographic printing method, roll coater coating method, bar coater coating method, air knife coating method, doctor blade method, etc. are used. be able to.

The biodegradable heat seal lacquer composition according to the present invention can be dried naturally or with warm air. After drying, the biodegradable heat seal lacquer composition of the present invention forms a substantially clear coating.

The film thickness of the coating film of the biodegradable heat-seal lacquer composition according to the present invention is arbitrary depending on the application, but for example, in the case of general usage, it is 5 to 1
It is preferably in the range of 00 μm.

Further, the method for adhering the biodegradable composite according to the present invention to another biodegradable substrate is not particularly limited, and a conventionally known adhesion method using a heat-seal lacquer composition is used. You can

As a specific example, the surface of the biodegradable composite of the present invention coated with the biodegradable heat-seal lacquer composition of the present invention is brought into contact with another biodegradable base material, and the temperature condition is set to 50. The biodegradable composite and other biodegradable base materials can be easily adhered by pressure-bonding for 0.01 to 5 seconds at a temperature of ˜250 ° C. and a pressure condition of 49 to 294 kPa. The biodegradable heat-seal lacquer composition according to the present invention may also be applied to the adhesive surface of another biodegradable substrate.

Among the biodegradable composites of the present invention, those having a biodegradable film such as a polylactic acid film as a base material can be suitably used as a packaging material such as an overlapping film.

[0115]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

Synthesis Example 1 500 parts of DL-lactide, 3.56 parts of ethylene glycol diester of 5-sodium sulfo-isophthalic acid,
As a ring-opening polymerization catalyst, 0.1 part of tin octylate was charged into a four-necked flask and heated at 190 ° C. for 1 hour under a nitrogen atmosphere to carry out ring-opening polymerization, thereby the metal salt of sulfonic acid was added to the main chain of polylactic acid. A lactic acid-based resin (I) was obtained.

Synthesis Example 2 DL-lactide 500 parts, 3-sodium sulfo-n-
1.62 parts of propanol and 0.1 part of tin octylate as a ring-opening polymerization catalyst were placed in a four-necked flask and heated at 190 ° C. for 1 hour under a nitrogen atmosphere to carry out ring-opening polymerization to give sulfone at the polymer end. A lactic acid resin (II) obtained by copolymerizing an acid metal salt was obtained.

Synthesis Example 3 1.78 parts of ethylene glycol diester of 5-sodium sulfo-isophthalic acid and polyglycerin having a degree of polymerization of 10 (Daicel Chemistry PGL10: hydroxyl group concentration 8)
5 parts of 50 KOHmg / g) was heated to 180 ° C. under reduced pressure and reacted for 20 minutes until the temperature reached 230 ° C. while removing generated ethylene glycol. After cooling the resulting mixture, 500 parts of DL-lactide. , 0.1 part of tin octylate as a ring-opening polymerization catalyst was charged in a four-necked flask,
Lactic acid-based resin (III) containing polysulfonic acid in the main chain of polylactic acid and further containing polyglycerin by ring-opening polymerization by heating at 190 ° C. for 1 hour under nitrogen atmosphere
Got The properties of these polyesters (A) are shown in Table 1.

[0119]

[Table 1]

Example 1 100 parts by mass of polyester (I) was dissolved in 100 parts by mass of methyl ethyl ketone, and an average particle size of 4.5 μm,
3 parts by mass of silica gel particles having a specific surface area of 95 m ² / g were added, mixed and dispersed in a ball mill, and then diluted with 100 parts by mass of ethyl acetate to obtain a heat-seal lacquer composition (I).

Further, the heat seal lacquer composition (I) was applied to a poly L-lactic acid film having a size of 300 mm length × 150 mm width by a gravure printing machine so as to have a dry film thickness of 2 μm, and a composite was prepared. Body (I) was obtained.

Examples 2 to 5 and Comparative Examples 1 and 2 According to Table 2, heat seal lacquer compositions were obtained in the same manner as in Example 1 and further composites were obtained.

[0123]

[Table 2]

Example 6 100 parts by mass of polyester (I) was dissolved in 100 parts by mass of methyl ethyl ketone, and the melting point thereof was 80 to 90 ° C.
Add 5 parts by mass of Carteva wax (American Wax Import and Refinery Association standard, Carnauba No. 1 (yellow type)) having a number average molecular weight of 500, mix and disperse in a ball mill, and then dilute with 100 parts by mass of ethyl acetate. Thus, a heat-seal lacquer composition (VIII) was obtained. Further, heat seal lacquer composition (VIII)
Using a gravure printing machine, 300 mm in length x 125 in width
2μ dry film thickness on mm-sized poly L-lactic acid film
m to obtain a composite of a poly L lactic acid film and a coating film of a heat-seal lacquer composition (hereinafter, simply referred to as a composite) (VIII).

Examples 7 to 11 According to Table 3, heat-sealing lacquer compositions were obtained in the same manner as in Example 6, and further composites were obtained.

[0126]

[Table 3] a: Carnauba wax, melting point 80 to 90 ° C, number average molecular weight 500 to 1000 b: Candelia wax, melting point 66 to 71 ° C, number average molecular weight 500 to 1000 c: Castor wax, melting point 86 to 90 ° C, number average molecular weight 500 to 1000 d : Ethylene bis stearamide

Using the composites (I) to (XIII), the performance of the composite as a biodegradable heat seal material, that is, heat seal strength, blocking resistance, brilliance, transparency and biodegradability. Was evaluated based on the following test method. The evaluation results are shown in Tables 4-5. In addition, the heat seal lacquer compositions (I) to (XIII) were used to evaluate the dispersibility of the antiblocking agent based on the following test method. The evaluation results are shown in Tables 4 and 5.

(I) Measurement of heat-sealing strength The composites were superposed on the surfaces coated with the heat-sealing lacquer composition, and heat-sealed under the conditions of 110 ° C., 98.1 kPa pressurization and 0.5 second pressurization time. did. Then 2
Tensile speed 100mm under the condition of 5 ℃ and relative humidity 65%
The T peel strength (N / 15 mm) was measured in / min.

(Ii) Blocking resistance test The composites were superposed on the surfaces coated with the heat-seal lacquer composition, and a load of 98.1 kPa was applied under the conditions of 40 ° C. and 65% relative humidity. 1 day later, 25 ℃,
The composites were peeled off under the condition of relative humidity of 65%, the appearance of the coating film on the adhesive surface was visually observed, and the degree of blocking resistance was evaluated in four levels according to the following criteria. ⊚: Excellent blocking resistance (easily peelable, no abnormality in coating film) ○: Good blocking resistance (coating surface is somewhat rough) Δ: Poor blocking resistance (some coating films are damaged) ) ×: No blocking resistance (most coating films are damaged)

(Iii) Transparency Test Through the coating film of the heat-seal lacquer composition, the characters previously printed on the surface of the substrate were visually observed, and the transparency was evaluated according to the following criteria in four steps. A: Characters can be clearly observed. ○: Characters appear to be a little sticky. Δ: Characters look quite blurry. X: Characters are blurred and cannot be read.

(Iv) Biodegradability test A composite of 10 cm × 10 cm was placed in a composter (raw trash processing machine, manufactured by Mitsui Home Co. (MAM)), and after 7 days, the sample form was visually observed and biodegraded. The degree of sex was evaluated in four levels according to the following criteria. ⊚: sample morphology is completely absent ∘: sample morphology is almost absent Δ: sample fragment is present x: sample morphology remains almost

(V) Dispersibility of anti-blocking agent 1000 mL of the heat-seal lacquer composition was sprayed with a pressure type pesticide sprayer, and the clogging of the nozzle was visually observed and evaluated according to the following evaluation criteria (the results are shown in Table 2). Three
Pointing out toungue). O: Good Δ: Slightly clogged ×: Severe clogging

[0133]

[Table 4]

[0134]

[Table 5]

[0135]

The heat-seal lacquer composition according to the present invention has excellent biodegradability and is also excellent in seal strength, blocking resistance, transparency and coating property.

The biodegradable composite according to the present invention also has excellent biodegradability, seal strength, blocking resistance, and
The coating film of the biodegradable heat seal lacquer composition according to the present invention has excellent transparency.

Furthermore, the biodegradable composite according to the present invention can be preferably used as a packaging material. Since the packaging material has biodegradability and can easily seal the contents, it is possible to improve the productivity, improve the convenience of life, and reduce the burden on the environment.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Miyamoto             2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo             Koki Co., Ltd. (72) Inventor Tayota Hotta             2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo             Koki Co., Ltd. (72) Inventor Toshiyuki Kaku             1-5-1 Taito, Taito-ku, Tokyo Toppan stamp             Imprint Co., Ltd. (72) Inventor Kazuki Okuyama             2-3-13, Kyobashi, Chuo-ku, Tokyo Toyo             Nki Manufacturing Co., Ltd. (72) Inventor Akira Suzuki             2-3-13, Kyobashi, Chuo-ku, Tokyo Toyo             Nki Manufacturing Co., Ltd. F-term (reference) 4F100 AK01A AK41A AP00A AR00A                       BA02 BA07 DG11A EH46B                       JC00 JC00A JC00B JL12                       JL12B JN01                 4J029 AA02 AB07 AD10 AE11 EA02                       EF02 HA01 HB01                 4J038 DD111 GA13 KA06 PC08

Claims (10)

[Claims] 1. A polyhydroxy acid polyester (A) containing a sulfonate structure represented by the following formula (1) and / or formula (2) in the molecule, an anti-blocking agent (B), and a solvent (E ) And a biodegradable heat-seal lacquer composition. [Chemical 1] (In the formula (1), X is an alkyl group having 20 or less carbon atoms, a cycloalkyl group, an aryl group, an arylalkyl group or hydrogen, a hydroxyl group, a nitro group, an amino group, an acyl group, a sulfonic acid group, an alkoxyl group and a halogen. And M is lithium, sodium, potassium or an amine represented by the following formula (3), m1 is an integer of 0 to 3, m2 is an integer of 1 to 4, and m1 + m2
Satisfies the relationship of 1 ≦ m1 + m2 ≦ 4. N1 represents an integer of 1 or more. ) [Chemical 2] (In the formula (2), R1 represents an alkylidene group having 20 or less carbon atoms, and M represents lithium, sodium, potassium or an amine represented by the following formula (3)) (In the formula (3), R2, R3, R4 and R5 each independently represent hydrogen, an alkyl group, a phenyl group or a benzyl group.) 2. The biodegradable heat seal lacquer according to claim 1, wherein the sulfonate structure represented by the formula (1) is a sulfonate structure represented by the following formula (4). Composition. [Chemical 4] (In the formula (4), R2, R3, R4 and R5 each independently represent hydrogen, an alkyl group, a phenyl group or a benzyl group.) 3. An anti-blocking agent is wax (C).
The biodegradable heat seal lacquer composition according to claim 1 or 2, wherein 4. An anti-blocking agent is an inorganic particle (D).
The biodegradable heat seal lacquer composition according to claim 1 or 2, wherein 5. A polyhydroxy acid-based polyester (A)
The sulfonate group is contained in a concentration range of ⁵ to 100 eq / 10 ⁶ g therein.
A biodegradable heat-seal lacquer composition according to any one of 1. 6. A polyhydroxy acid-based polyester (A)
Contains 80 mol% or more of lactic acid residues, The biodegradable heat seal lacquer composition according to any one of claims 1 to 5, wherein 7. A polyhydroxy acid-based polyester (A)
Contains an L-lactic acid residue and a D-lactic acid residue, and has an L / D molar ratio of 1 to 9, wherein the biodegradable heat-seal lacquer composition according to claim 6. 8. A biodegradable base material and a biodegradable coating film using the biodegradable heat-seal lacquer composition according to any one of claims 1 to 7, which is applied to the upper surface of the biodegradable base material. A biodegradable complex containing. 9. A biodegradable film as the biodegradable substrate,
9. The biodegradable product according to claim 8, which contains one or more members selected from the group consisting of biodegradable plastic, paper, biodegradable fiber cloth, biodegradable nonwoven fabric and wood as a constituent element. Complex. 10. The biodegradable composite according to claim 8, wherein the biodegradable substrate contains a polylactic acid-based film as a constituent element.