JPWO2010047285A1 - Tubular molding material and heat shrinkable film - Google Patents

Abstract

Provided are a tubular molding material mainly composed of a vinyl aromatic hydrocarbon and a conjugated diene, which have excellent bubble formation stability when producing a heat-shrinkable film, and a heat-shrinkable film using the molding material. (1) A tubular molding material containing as a main component a block copolymer comprising a vinyl aromatic hydrocarbon and a conjugated diene, and (a) a microcrystalline wax having a melting point of 75 ° C to 98 ° C as defined in JISK2235. And (b) a glyceride having an average degree of polymerization of the glycerin skeleton of glyceride of 1 to 10 and R of 11 to 21 in the fatty acid ester group represented by the general formula R—COO—. Tubular molding material. Furthermore, it is a tubular molding material containing (2) (I) 0.01 to 3 parts by mass of microcrystalline wax and (b) 0.01 to 3 parts by mass of glyceride.

Description

  The present invention relates to a tubular molding material and a heat shrink film using the same.

Conventionally, vinyl chloride has been used for heat-shrinkable films used for shrink wrapping, but in recent years, block copolymers composed of vinyl aromatic hydrocarbons and conjugated dienes, or resin compositions thereof have come to be used. ing. There are several types of manufacturing methods for the heat-shrinkable film, and the most convenient method is a manufacturing method called a tubular method.
It is difficult to produce a heat-shrinkable film by the tubular method using the block copolymer consisting of the vinyl aromatic hydrocarbon and conjugated diene or the resin composition thereof, and temperature control of the stretching process to stabilize the molding. It is disclosed in Japanese Patent Application Laid-Open No. H10-228707 that strictly performs the above. Further, Patent Document 2 discloses that a block copolymer composed of a certain kind of vinyl aromatic hydrocarbon and a conjugated diene is suitable for this tubular method.
Japanese Patent Laid-Open No. 50-6673 JP 07-216186 A

  In the tubular method, a melted resin is extruded into a tube shape from an annular die, and the tube is controlled to an appropriate temperature, and then a gas is injected into the tube to be expanded (hereinafter referred to as “bubble formation”). This is a method for producing a heat-shrinkable film by stretching in a direction perpendicular to the direction. The force required to stretch the film in forming the tube can be obtained by injecting a gas into the tube and the difference between the internal pressure of the tube obtained and the external pressure of the tube.

  The tubular film forming method has a problem that the inner surfaces of the film block each other because the film extruded in a tube shape from the die is folded by a pinch roll before being cooled to room temperature. This makes it difficult to peel off the films again, making it impossible to produce a stable film.Furthermore, with a film forming machine that is folded by a pinch roll near the softening temperature of the resin or higher, stable production is possible. Sometimes it became more difficult.

  In the tubular film-forming method, the inflated tube may be brought into contact with the cooling ring to fix the film width, and the conventional resin composition composed of vinyl aromatic hydrocarbon and conjugated diene has poor slipping property with the cooling ring. In some cases, it was impossible to produce a stable film.

  Therefore, in order to enable stable film production using a resin composition containing a block copolymer composed of a vinyl aromatic hydrocarbon and a conjugated diene, a tubular molding material having both blocking resistance and slipperiness. Development was desired.

  The present invention relates to a tubular molding material mainly composed of a vinyl aromatic hydrocarbon and a conjugated diene, which has excellent bubble formation stability when producing a heat-shrinkable film, and a heat-shrinkable film using the molding material The purpose is to provide.

That is, the present invention has the following gist.
(1) A tubular molding material containing as a main component a block copolymer comprising a vinyl aromatic hydrocarbon and a conjugated diene, and (a) a microcrystalline having a melting point of 75 ° C. to 98 ° C. as defined in JIS K2235. A wax, and (b) a glyceride having an average polymerization degree of glycerin skeleton of glyceride of 1 to 10 and R of 11 to 21 in the fatty acid ester group represented by the general formula R—COO—. Contains tubular molding material.
(2) The tubular molding material as described in (1) above, which comprises 0.01 to 3 parts by mass of microcrystalline wax and (b) 0.01 to 3 parts by mass of glyceride.
(3) A heat-shrinkable film using the tubular molding material described in (1) or (2) above.
(4) A coating material for PET bottles using the heat shrink film according to (3).

By using the tubular molding material of the present invention, the blocking resistance and slipperiness are improved, and blocking between films due to physical factors such as pressure bonding by a nip roll when a film is formed by the tubular method is eliminated. .
Furthermore, the frictional resistance due to contact between the film such as a cooling ring and the film is reduced, and a heat-shrinkable film having a good appearance can be stably produced.

  The tubular molding material of the present invention is essentially composed of a block copolymer composed of a vinyl aromatic hydrocarbon and a conjugated diene, and contains (i) microcrystalline wax and (b) glyceride. .

  In the tubular method, the process of folding a tubular film with a nip roll is often performed, and the films are physically bonded to each other. Therefore, when the softening point of the tubular molding material to be used is low or the film temperature is high. When folded by a nip roll in a state, the films may be fused to cause blocking, and a high-quality film may not be stably produced.

  This blocking can be mitigated by raising the glass transition temperature of the tubular molding material, but on the other hand, the stretchability is deteriorated and further the shrinkability at low temperature is impaired. Therefore, in order to exhibit good anti-blocking performance without increasing the glass transition temperature of the molding material, it is essential to add a filler or additive having anti-blocking performance.

Examples of the filler having anti-blocking performance include high impact polystyrene (HIPS), crosslinked beads of vinyl aromatic hydrocarbon- (meth) acrylic acid ester and / or (meth) acrylic acid copolymer, vinyl aromatic hydrocarbon copolymer. Examples thereof include inorganic beads such as polymer crosslinked beads, silica beads, and quartz beads.
When a film appearance with good transparency is required, preferably HIPS, vinyl aromatic hydrocarbon- (meth) acrylic acid ester and / or (meth) acrylic acid copolymer crosslinked beads, vinyl aromatic hydrocarbon It is preferred to use copolymer crosslinked beads. The mixing ratio of these fillers is 10 parts by mass or less with respect to 100 parts by mass of the block copolymer composition, preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass. .

  Examples of the additive having anti-blocking performance include a lubricant, an antifogging agent, an antistatic agent and the like, and a lubricant is particularly common. As a lubricant, fatty acid, fatty acid ester, fatty acid amide, glycerin fatty acid ester (glyceride), sorbitan fatty acid ester, pentaerythritol fatty acid ester, sucrose fatty acid ester, propylene glycol fatty acid ester, etc., polyolefin wax such as polyethylene wax, polypropylene, Paraffin wax, microcrystalline wax, petrolatum and the like can be mentioned.

In the tubular method, after the resin melted from the die is discharged into a tube shape, it is immediately folded by a nip roll in a state where it is not sufficiently cooled down. In the process, since it may be folded by a nip roll in a hot water tank set at a stretching temperature, it is necessary to exhibit anti-blocking performance at a higher temperature.
In order to develop anti-blocking performance at high temperatures, in addition to the above-mentioned means for adding a filler having anti-blocking performance, higher melting point hydrocarbon waxes such as polyethylene wax, polypropylene wax, microcrystalline wax, paraffin Use of wax, petrolatum and the like is preferred. More preferred are polyethylene wax, polypropylene wax and microcrystalline wax, with microcrystalline wax being most preferred.

The melting point of the microcrystalline wax is preferably 75 ° C. to 98 ° C. in accordance with JIS K2235-5.3.2. When the melting point of the microcrystalline wax is less than 75 ° C., the microcrystalline wax easily migrates too much to the film surface, leading to deterioration of the appearance of the film, and may cause deterioration of printability on the film. On the other hand, when the melting point of the microcrystalline wax exceeds 98 ° C., the transfer speed to the film surface is not sufficient, and an immediate anti-blocking performance may not be obtained. Although there is a method of increasing the temperature of the film in order to ensure a sufficient transition speed, it may be difficult to form a stable tube.
Here, the standard of JIS K2235-5.3.2 corresponds to the standard of ASTM D1321.

The melting point of the microcrystalline wax in the present invention is measured by the following method.
Device name: Melting point tester (made by Meitec Co., Ltd., trade name: Automatic wax melting point tester WMP-104 type)
Test method: In accordance with JIS K2235-5.3.2, when a molten sample is attached and solidified on the mercury bulb of a thermometer for melting point measurement, heated under specified conditions, and the first drop falls from the thermometer Measure the temperature.

The addition amount of the microcrystalline wax is 0.01 to 3 parts by mass, preferably 0.03 to 1 part by mass, and more preferably 0.1 to 0.3 parts by mass with respect to 100 parts by mass of the block copolymer. . If the microcrystalline wax is less than 0.01 parts by mass, sufficient anti-blocking performance may not be exhibited. On the other hand, if the microcrystalline wax exceeds 3 parts by mass, extrusion by an extruder may not be stable.
When a high-melting-point hydrocarbon wax is used alone, the transfer rate to the film surface is not sufficient, and the anti-blocking performance with excellent immediate effect may not be obtained. In order to immediately exhibit the anti-blocking performance at a high temperature after discharging the molten resin, it is preferable to use a lubricant having a high migration property in combination.

As the lubricant having a high migration property, it is preferable to select a lubricant having a moderately low solubility in the tubular molding material. For tubular molding materials composed mainly of block copolymers composed of vinyl aromatic hydrocarbons and conjugated dienes, lubricants with moderately high hydrophilicity, such as glycerin fatty acid esters (glycerides), sorbitan fatty acid esters, pentaerythritol It is preferable to use a fatty acid ester of a polyhydric alcohol such as a fatty acid ester or sucrose fatty acid ester, more preferably glyceride.
The addition amount of glyceride is 0.01-3 mass parts with respect to 100 mass parts of block copolymers, Preferably, it is 0.03-1 mass parts, More preferably, it is 0.1-0.5 mass parts. If the glyceride is less than 0.01 part by mass, the slipping property with the sizing ring may not be sufficiently exhibited. On the other hand, if the glyceride exceeds 3 parts by mass, extrusion may not be stable.

In the glyceride, R in the fatty acid ester group represented by R—COO— preferably has 11 to 21 carbon atoms, and more preferably 17 to 21 carbon atoms.
When the carbon number of R of glyceride is less than 11, the compatibility with hydrocarbon wax decreases, the speed of developing anti-blocking performance derived from hydrocarbon wax decreases, and moderate solubility in tubular molding materials. It is difficult to grant. If it is 23 or more, the hydrophilicity is too low, and sufficient slipperiness with the cooling ring may be difficult to be exhibited.

The glyceride preferably has an average degree of polymerization of the glycerin skeleton of 1 to 10, more preferably 1 to 4.
If the average degree of polymerization of the glycerin skeleton exceeds 10, the hydrophilicity will increase too much, and appropriate solubility will be obtained in the tubular molding material mainly composed of a block copolymer composed of vinyl aromatic hydrocarbon and conjugated diene. It becomes difficult to grant. Although the HLB value is generally used as an index representing the hydrophilicity of glyceride, the HLB value of glyceride suitable for use in the tubular molding material of the present invention is 3 to 16, more preferably 4 to 12. If the HLB value of glyceride is less than 3, the hydrophilicity is too low, and the slipperiness with the cooling ring may not be sufficiently obtained. On the other hand, if the HLB value of glyceride exceeds 16, the compatibility with the tubular molding material may be too low and it may be difficult to disperse in the resin.

  Examples of the vinyl aromatic hydrocarbon used in the production of the block copolymer of the present invention include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene, 2,5 -Dimethyl styrene, α-methyl styrene, vinyl naphthalene, vinyl anthracene, and the like. Among them, styrene is preferable.

  Conjugated dienes used for the production of the block copolymer of the present invention include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1, Examples include 3-pentadiene and 1,3-hexadiene. Among them, 1,3-butadiene and isoprene are preferable.

  The block copolymer used in the present invention polymerizes vinyl aromatic hydrocarbon and conjugated diene monomers in a dehydrated organic solvent using an organolithium compound as an initiator and optionally a randomizing agent. Can be manufactured. Examples of organic solvents include aliphatic hydrocarbons such as butane, pentane, hexane, isopentane, heptane, octane and isooctane, alicyclic hydrocarbons such as cyclohexane, methylcyclohexane and ethylcyclohexane, and aromatics such as benzene, toluene, ethylbenzene and xylene. Group hydrocarbons can be used.

  An organolithium compound is a compound in which one or more lithium atoms are bonded in the molecule, for example, monofunctional such as ethyllithium, n-propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, etc. Besides organolithium compounds, polyfunctional organolithium compounds such as hexamethylene dilithium, butadienyl dilithium, isoprenyl dilithium and the like can also be used.

Tetrahydrofuran (THF) is mainly used as the randomizing agent. In addition, ethers, amines, thioethers, phosphoramides, alkylbenzene sulfonates, potassium or sodium alkoxides, and the like can also be used.
Examples of ethers include dimethyl ether, diethyl ether, diphenyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, and the like. As the amines, tertiary amines such as trimethylamine, triethylamine, tetramethylethylenediamine, and internal cyclic amines can be used. In addition, triphenylphosphine, hexamethylphosphoramide, potassium or sodium alkylbenzenesulfonate, potassium, sodium butoxide, or the like can be used as a randomizing agent.

  As addition amount of these randomizing agents, it is 10 mass parts or less with respect to 100 mass parts of all preparation monomers, and 0.001-8 mass parts is preferable. The addition time may be before the start of the polymerization reaction or during the polymerization. Further, it can be added as required.

  The block copolymer solution thus obtained has a block copolymer inactivated by adding a sufficient amount of a polymerization terminator such as water, alcohol or carbon dioxide to inactivate the active terminal. Activated. As a method for recovering the block copolymer from this block copolymer solution, a method of depositing this solution in a poor solvent such as methanol and the like, a method of evaporating the solvent with a heating roll or the like (a drum dryer method) ), A method of removing the solvent with a vent type extruder after concentrating the solution with a concentrator, a method of dispersing the solution in water and blowing the water vapor to remove the solvent by heating (steam stripping method). used.

  In the tubular molding material of the present invention, the block copolymer thus obtained can be used alone, or a plurality of types of block copolymers can be used in combination. Furthermore, other types of polymers such as vinyl aromatic hydrocarbon polymers, graft copolymers of vinyl aromatic hydrocarbon polymers and conjugated dienes, copolymers of vinyl aromatic hydrocarbons and (meth) acrylic acid esters. It can also be used by mixing with a polymer, polyolefin, etc., and the blending ratio is preferably 30 parts by mass or less with respect to 100 parts by mass of the composition of the block copolymer. For mixing, a method of mixing while melting with an extruder, a method of removing the solvent by the above method after blending the solutions of the respective components, etc. are mainly used.

  As the additive, in addition to the above-mentioned lubricant, antifogging agent and antistatic agent, there are mainly a heat stabilizer, a weather resistance improver and the like. Examples of the heat stabilizer include 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-3 , 5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate, n-octadecyl-3- (4-hydroxy-3,5-di-tert-butylphenyl) propionate, etc. Phosphorous antioxidants such as phenolic antioxidants, 2,2'-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite An agent or the like is used.

  Examples of the weather resistance improver include benzotriazole ultraviolet absorbers such as 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole and tetrakis (2,2,6,6). Examples include hindered amine type weather resistance improvers such as 6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate. White oil and silicone oil can also be added.

  These additives are preferably contained in the block copolymer composition in an amount of 5 parts by mass or less.

The heat-shrinkable film using the tubular molding material of the present invention is particularly preferably used for heat-shrinkable labels, heat-shrinkable cap seals, and the like, and can also be suitably used for packaging films and the like.
As mentioned above, although the tubular molding material of this invention and the heat shrink film using the same were demonstrated, these are one Embodiment of this invention, This invention is not limited to these.

  EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[Reference Example 1]
(1) 490 kg of cyclohexane was charged in a reaction vessel.
(2) While adding 35.7 kg of styrene monomer and stirring, 1600 mL of n-butyllithium (10 mass% cyclohexane solution) was added and polymerized at an internal temperature of 30 ° C.
(3) The internal temperature was lowered to 40 ° C., 69.3 kg of styrene monomer and 8.9 kg of butadiene monomer were added all at once, and then this was fully polymerized.
(4) The internal temperature was set to 60 ° C., and 69.3 kg of styrene and 26.8 kg of butadiene were added all at once to complete the polymerization.

[Reference Example 2]
(1) 500 kg of cyclohexane was charged into the reaction vessel.
(2) While adding 8.0 kg of styrene monomer and stirring, 1280 mL of n-butyllithium (10 mass% cyclohexane solution) was added and polymerized at an internal temperature of 30 ° C.
(3) While maintaining the internal temperature at 80 ° C., a total amount of 110.0 kg of styrene monomer and a total amount of 13.4 kg of butadiene monomer were simultaneously added at a constant addition rate of 87.8 kg / h and 10.7 kg / h, respectively. It was added, and the state was maintained for a sufficient time after the end of the addition.
(4) After the butadiene gas was completely consumed, 18.6 kg of butadiene was added all at once at an internal temperature of 75 ° C., and this was subsequently polymerized.
(5) Further, 50.0 kg of styrene monomer was added all at once to complete the polymerization.

[Reference Example 3]
(1) 500 kg of cyclohexane was charged into the reaction vessel.
(2) While adding 4.0 kg of styrene monomer and stirring, 1950 mL of n-butyllithium (10 mass% cyclohexane solution) was added and polymerized at an internal temperature of 30 ° C.
(3) While maintaining the internal temperature at 80 ° C., a total amount of 119.0 kg of styrene monomer and a total amount of 11.8 kg of butadiene monomer were simultaneously added at a constant addition rate of 100.8 kg / h and 10.0 kg / h, respectively. It was added, and the state was maintained for a sufficient time after the end of the addition.
(4) After the butadiene gas was completely consumed, 36.4 kg of butadiene was added all at once at an internal temperature of 70 ° C., and this was subsequently polymerized.
(5) Further, 28.8 kg of styrene monomer was added all at once to complete the polymerization.

  The characteristics of the block copolymers of Reference Examples 1 to 3 thus obtained are shown in Table 1. In the table, A represents a polystyrene block, B represents a polybutadiene block, C represents a random block, and D represents a tapered block.

  The block copolymers of Reference Examples 1 to 3 were mixed in the composition of Reference Example 1 / Reference Example 2 / Reference Example 3 = 33.3% by mass / 33.3% by mass / 33.4% by mass, and mixed resin composition It was a thing. And various lubricants were further added with the mixing | blending shown in Table 2-Table 4 with respect to 100 mass parts of this mixed resin composition. And it melt-kneaded at 200 degreeC using the single screw extruder, and obtained the tubular molding material of Examples 1-11 and Comparative Examples 1-8. The melting point of microcrystalline wax was measured according to the method described in JIS K2235-5.3.2.

  The tubular molding materials of Examples and Comparative Examples shown in Table 5 and Table 6 were used, using a tubular film forming machine (model: MCE-50, manufactured by YI-CHEN) of a stretch preheating method using a general water tank, While performing the film forming test according to the following method, the state was observed and the obtained heat-shrinkable film was also evaluated according to the method described later. The results are shown in Tables 5 and 6.

(1) Tubular molding materials having the compounding ratios shown in Tables 5 and 6 were put into an extruder, melted and kneaded at 200 ° C. to be sufficiently plasticized, and then discharged into a tube shape. Subsequently, gas was injected into the tube, and from the outside of the tube, an arbitrary tube diameter was obtained while cooling with an appropriate air so that the tube swelled stably.
(2) Fold the tube with a nip roll positioned at an arbitrary height from the die, and adjust the gap distance of the die, the screw rotation speed, and the nip roll speed as necessary so that the average thickness of the resulting film is about 0.1 mm. Adjusted. The crimping force of the nip roll was adjusted to the minimum necessary force that prevents the gas in the first stage tube from leaking after the nip roll.
(3) Films after being folded by nip rolls were collected and evaluated for blocking between films according to the following criteria.

(A) Peel strength test between tube inner surfaces The collected tube is based on the direction in which the tube flows (hereinafter abbreviated as “MD direction”) and the direction perpendicular to the tube (hereinafter abbreviated as “TD direction”). As a result, a test piece was cut out to a length of 15 mm in the MD direction and a length of 15 cm in the TD direction. Next, a marked line is drawn at a location of 4 cm from the end in the TD direction of the test piece, using this as a boundary line, the films on the short length side are peeled off, and the peeled films are each bent by 90 degrees along the marked line, A T-shaped test piece was obtained. Using Tensilon tensile tester RTC-1210 manufactured by A & D Co., Ltd., both ends of the film on the peeled side were fixed with a chuck, and the peel strength when pulled at a pulling speed of 200 mm / min [N ] Was measured. The measured values were averaged from 15 seconds to 60 seconds after the start of tension, and the same operation was repeated 10 times to calculate an average value Z [N].

(4) The film after passing through the nip roll is passed through an 85 ° C. hot water tank and stretched and preheated, and a cooling ring for fixing the size in the tube radial direction so as to obtain an arbitrary tube diameter again (hereinafter this ring is referred to as a sizing ring). A gas was inflated until it fully contacted with each other to form a bubble (hereinafter, this operation is referred to as sizing). The bubble formation stability was evaluated according to the following criteria.

(B) Gas injection property "Gas injection property" evaluated the surface state of tube inner surfaces by visual observation, and evaluated on the following evaluation criteria.
Good: The inner surface of the tube is easily peeled off by gas injection.
Yes: The inner surfaces of the tubes are peeled apart by the gas injection, but there is resistance and a sound is generated when the inner surfaces of the tubes are opened, or there is an unstable vibration.
Defect: The inner surfaces of the tubes are blocking each other, causing the film to break when opened, or completely blocking the gas injection operation.

(C) Sliding property with sizing ring “Sliding property with sizing ring” means that when the gas is injected until the outer surface of the tube is in sufficient contact with the sizing ring, the sliding property between the film and the sizing ring is determined visually. It was evaluated according to the evaluation criteria.
Good: Stable between the tube and the sizing ring without any drag sound.
Possible: In the sliding between the tube and the sizing ring, the sound derived from drag is slightly unstable.
Defect: The tube is caught on the sizing ring, and the tube is significantly deformed or ruptured.

(5) The film after bubble formation was taken out to obtain a heat-shrinkable film.
(D) Measurement of heat shrinkage rate The heat shrinkage rate of the heat shrinkable film was measured by the following method.
(1) A test piece having an MD direction of 100 mm and a TD direction of 100 mm was cut out from the stretched film.
(2) The test piece was immersed in warm water at 100 ° C. for 10 seconds, taken out, immediately cooled with water and wiped with moisture, and then the MD and TD length L (mm) of the test piece were measured.
(3) The thermal contraction rate was calculated by the following formula.
Thermal contraction rate (%) = {(100.0−L) /100.0} × 100

  From the results of Table 5 and Table 6, the tubular molding material of the present invention can be easily opened without blocking the films even when the films are pressure-bonded by a nip roll at a high temperature. It can be seen that a heat-shrinkable film that is stable and excellent in heat-shrinkability can be obtained.

On the other hand, Comparative Examples 1 to 4 containing microcrystalline wax and glyceride outside the structure claimed in the present invention, and Comparative Examples 5 to 8 containing different types of lubricants are blocking resistance between films and sizing ring. The slipperiness of the film was not sufficiently exhibited, the formation of bubbles was lacking, and a good quality film could not be collected.
Furthermore, when the microcrystalline wax or glyceride content exceeds the specified range, the extrusion stability is remarkably lacking, and when the content is below the specified range, the anti-blocking effect and the slipperiness with the sizing ring are also present. It was hardly expressed and could not be used for stable film formation.

  As described above, the tubular molding material of the present invention is a material suitable for manufacturing a heat-shrinkable film by a tubular method, and a film using this material can be applied to a bottle label, a cap seal, and the like. Furthermore, the tubular material of the present invention can be suitably used for various applications that require blocking resistance at high temperatures other than the tubular film forming method.

Claims (4)

A tubular molding material containing, as a main component, a block copolymer comprising a vinyl aromatic hydrocarbon and a conjugated diene,
(A) a microcrystalline wax having a melting point defined by JIS K2235 of 75 ° C to 98 ° C;
(B) Glyceride having an average polymerization degree of glycerin skeleton of glyceride of 1 to 10 and R of 11 to 21 in the fatty acid ester group represented by the general formula R—COO—
A tubular molding material. The tubular molding material according to claim 1, comprising 0.01 to 3 parts by mass of microcrystalline wax (I) and 0.01 to 3 parts by mass of glyceride (B). A heat shrink film using the tubular molding material according to claim 1. The coating material for PET bottles using the heat-shrink film of Claim 3.