JP2008050433A - Method for manufacturing copolyester film adhesive material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a film hot melt adhesive windable without blocking. <P>SOLUTION: This method for manufacturing a copolyester film adhesive material comprises a step of heat melting a copolyester that has a number average molecular weight of ≥10,000, a melting point of 70-150°C and a glass transition point of ≤20°C, and contains an inorganic compound of ≤5 mass%, and a step of extruding the melted copolyester through a die on a rotating drum cooled at ≤20°C to quench it. The method is also characterized in that the inorganic compound is silica or calcium carbonate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a copolyester film adhesive material.

  Hot melt adhesives made of copolymerized polyesters have features such as pollution-free and are used in a wide range of fields. As a method of using hot melt adhesive, there is a method in which a hot melt resin is heated and melted and applied to another adherend, which is then subjected to thermocompression bonding. In addition, a method of thermocompression bonding with another fabric is known. In recent years, in order to further save the labor of such a method, a method using a film-like hot melt adhesive capable of reducing the step of heating and melting is known.

  However, when producing a film-like hot melt adhesive, there is a problem that the films are easily blocked and difficult to scrape off, and it is difficult to form a film because the melt viscosity is low.

In order to prevent the films from blocking each other, Patent Document 1 and Patent Document 2 disclose a method of mixing a polymer resin such as an amorphous polyester resin, a terpene phenol resin, or an epoxy resin with a hot melt adhesive. Has been. Although the film obtained by this method has controlled blocking and adhesive strength, it contains a polymer resin component other than the hot melt adhesive, so the melting point and glass transition point change, and the adhesive temperature rises. The performance of the melt adhesive may be reduced.
Further, when the film is formed by the T-die method, the melt viscosity is low, so that there are problems that the film is torn during film formation and is difficult to peel off from the roller.
JP 2002-138269 A JP 2003-171640 A

  The subject of this invention is solving the said problem and providing the manufacturing method of the film-form hot-melt-adhesive material which can be scraped off without blocking.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a film adhesive material can be provided by using a copolyester having specific characteristics, and have completed the present invention.
That is, the gist of the present invention is as follows.
(1) A copolymer polyester containing an inorganic compound of 5% by mass or less, having a number average molecular weight of 10,000 or more, a melting point of 70 to 150 ° C., and a glass transition point of 20 ° C. or less is heated and melted, and 20 ° C. from the die. A method for producing a copolyester film adhesive material, which is extruded on a rotating cooling drum cooled below and quenched.
(2) The method for producing a copolyester film adhesive material according to (1), wherein the inorganic compound is silica or calcium carbonate.
(3) A film obtained by extruding onto a rotating cooling drum and quenching is obtained at a temperature of (glass transition point−10) to (glass transition point + 70) ° C. at a magnification of 1.1 to 5.0 times in the longitudinal direction. The method for producing a copolyester film adhesive material according to (1) or (2), wherein the film is stretched and stretched in the transverse direction at a magnification of 1.1 to 5.0 times.
(4) The method for producing a copolyester film adhesive material according to (3), wherein the stretched film is heat-set at a temperature equal to or lower than the melting point for 1 to 60 seconds.

  According to the present invention, it is possible to provide an adhesive material made of a copolyester and in the form of a film, and its industrial utility value is extremely high.

Hereinafter, the present invention will be described in detail.
In the present invention, the copolyester is a resin mainly composed of equimolar amounts of a dicarboxylic acid component and a glycol component.

Dicarboxylic acid components include terephthalic acid, isophthalic acid, phthalic anhydride, naphthalene dicarboxylic acid, aromatic dicarboxylic acids such as 4,4'-dicarboxybiphenyl, 5-sodium sulfoisophthalic acid, oxalic acid, malonic acid, succinic acid , Saturated aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, octadecanedioic acid, and aicosanedioic acid, fumaric acid, maleic anhydride, itaconic acid, mesaconic acid, citraconic acid, etc. Unsaturated aliphatic dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornenedicarboxylic acid, alicyclic dicarboxylic acid of tetrahydrophthalic acid or ester thereof Examples thereof include formable derivatives.
Among these dicarboxylic acid components, terephthalic acid, isophthalic acid, adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid are preferred because of their versatility. These ratios are selected so that the melting point and glass transition point of the copolyester are within the ranges defined in the present invention.

Examples of the glycol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 2-methyl-1,3. -Propanediol, 2,2-diethyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, 2-ethyl 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,5-pentanediol, 1 , 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, (4), aliphatic glycols such as 8 (9) -bis (hydroxymethyl) -tricyclo (5.2.1.1/2.6) decane, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, Bisphenol A, bisphenol S, bisphenol C, bisphenol Z, bisphenol AP, ethylene oxide adduct or propylene oxide adduct of 4,4′-biphenol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1, Examples include alicyclic glycols such as 4-cyclohexanedimethanol, polyethylene glycol, and polypropylene glycol.
Among these glycol components, ethylene glycol, 1,2-propanediol, 1,4-butanediol, neopentyl glycol, ethylene oxide adduct of bisphenol A, and 1,4-cyclohexanedimethanol are versatile and preferable. . These ratios are selected so that the melting point and glass transition point of the copolyester are within the ranges defined in the present invention.

In the copolymerized polyester, a hydroxycarboxylic acid can be used as a copolymerization component in accordance with purposes such as appropriate flexibility, improved adhesion, and adjustment of the glass transition point. As the hydroxycarboxylic acid, an ethylene oxide adduct of p-hydroxybenzoic acid, an ethylene oxide adduct of m-hydroxybenzoic acid, an ethylene oxide adduct of o-hydroxybenzoic acid, lactic acid, oxirane, β-propiolactone, β-butyrolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyisobutyric acid, 2-hydroxy-2-methylbutyric acid, 2-hydroxyyoshi Examples include valeric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid, 10-hydroxystearic acid, and the like.
Of these hydroxycarboxylic acids, ε-caprolactone is preferred because of its versatility. These ratios are selected so that the melting point and glass transition point of the copolyester are within the ranges defined in the present invention.

If it is a small amount, a tri- or higher functional carboxylic acid component or alcohol component may be added to the copolymer polyester as a copolymer component. Examples of the tri- or higher functional carboxylic acid component include aromatics such as trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, trimesic acid, and the like. Examples thereof include carboxylic acids and aliphatic carboxylic acids such as 1,2,3,4-butanetetracarboxylic acid.
Examples of the tri- or higher functional alcohol component include glycerol, trimethylolpropane, trimethylolethane, pentaerythritol, α-methylglucose, mannitol, and sorbitol.
These do not necessarily need to be used alone, and can be used in combination of two or more according to the properties desired to be imparted to the resin. At this time, the proportion of the tri- or higher functional monomer is suitably about 0.2 to 5 mol% with respect to the total carboxylic acid component or the total alcohol component. If the amount added is less than 0.2 mol%, the added effect is not manifested, and if the amount exceeds 5 mol%, the gelation may exceed the gel point during polymerization.

  Moreover, monocarboxylic acid and monoalcohol may be copolymerized with the polyester resin. Examples of monocarboxylic acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, benzoic acid, p-tert-butylbenzoic acid, cyclohexane acid, 4-hydroxyphenyl stearic acid, and the like. Examples of the alcohol include octyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, and 2-phenoxyethanol.

  In the present invention, the number average molecular weight of the copolyester needs to be 10,000 or more, and preferably 15,000 or more. When the molecular weight is less than 10,000, the melt viscosity becomes too low, and therefore, when forming a film by the T-die method, there is a problem in that the film is broken during film formation or the film is hardly peeled off from the roller.

  The melting point (hereinafter abbreviated as Tm) of the copolyester is required to be 70 to 150 ° C, and preferably 70 to 120 ° C. When Tm exceeds 150 ° C., the bonded body may be melted at the time of bonding, which is not preferable. Moreover, since it will deform | transform into a film adhesive material depending on storage conditions that it is less than 70 degreeC, it is unpreferable.

  Furthermore, the glass transition point (hereinafter abbreviated as Tg) of the copolyester needs to be 20 ° C. or less. When Tg exceeds 20 ° C., the temperature must be set high when bonding, and the material to be bonded is limited, which is not preferable. Moreover, it is preferable that Tg is -20 degreeC or more. When Tg is less than −20 ° C., the operability during film formation may be impaired.

  The number average molecular weight of the copolymerized polyester can be adjusted to the above range by controlling the polymerization time and the depolymerization amount, and Tm and Tg can be adjusted to the above ranges by setting the combination of monomers to be copolymerized.

  The copolyester can be produced by combining the above monomers and performing polycondensation by a known method. For example, all monomer components and / or low polymers thereof are reacted at 180 to 250 ° C. for about 2.5 to 10 hours under an inert atmosphere to carry out an esterification reaction, followed by 220 to 220 under a reduced pressure of 130 Pa or less. A method in which the polycondensation reaction is allowed to proceed until a desired molecular weight is reached at a temperature of 280 ° C. can be mentioned.

  In the esterification reaction and polycondensation reaction, germanium compounds such as germanium dioxide, titanium compounds such as tetrabutyl titanate, metal acetates such as zinc acetate and magnesium acetate, antimony trioxide, hydroxybutyltin oxide, Polymerization is performed using an organic tin compound such as tin octylate. The amount of catalyst used at that time is usually 0.5% by mass or less based on the resin to be produced.

  In addition, when a desired acid value or hydroxyl value is imparted to the copolyester, following the polycondensation reaction, a polybasic acid component or a polyvalent glycol component is further added, and depolymerization is performed in an inert atmosphere. Do it.

  In the present invention, the copolyester film adhesive material is obtained by molding the copolyester into a film. The thickness is preferably 200 μm or less. Moreover, when not extending | stretching at the time of manufacture, it is preferable that the thickness is 50-200 micrometers, and when extending | stretching, it is preferable that it is 12-100 micrometers. When the thickness of the film adhesive material exceeds 200 μm, the degree of uniformity is deteriorated, and the commercial value is deteriorated such that the appearance of wrinkling is deteriorated or wrinkles are generated.

  In this invention, it is preferable that a copolyester film adhesive material contains an inorganic compound, The content needs to be 5 mass% or less, and it is further more preferable that it is 3 mass% or less. By containing an inorganic compound, not only the wrinkles of the film adhesive material can be reduced, but also the effect of preventing the above-described fusion at the time of scraping can be obtained. On the other hand, if the content of the inorganic compound exceeds 5% by mass, film formation may be difficult, and physical properties of the obtained film adhesive material, particularly heat seal strength, may be significantly reduced, causing a problem in practical use. This is not preferable.

  Examples of the inorganic compound include talc, silica, calcium carbonate, magnesium carbonate, kaolin, mica, titanium oxide, aluminum oxide, zeolite, clay, and glass beads. Of these, silica and magnesium carbonate are preferred because of their versatility. In the case of adding an inorganic compound, it is preferable to use master pellets prepared in advance by melt-kneading and compounding a copolymerized polyester and an inorganic compound with a twin-screw extruder.

  In the present invention, the copolyester film adhesive material is an ultraviolet ray inhibitor, a light stabilizer, an antifogging agent, an antifoggant, an antistatic agent, a flame retardant, an anti-coloring agent, an antioxidant, and a filling depending on the application. You may contain additives, such as a material and a pigment.

  Next, the manufacturing method of the film adhesive material of this invention is demonstrated. Examples of the method for producing the film adhesive material of the present invention include known film forming methods such as T-die method and I-die method.

  In the T-die method, the dried copolymerized polyester is put into an extruder, the molten resin is extruded from the T-die into a film shape, the film is pressed against a rotating cooling drum, rapidly cooled, and wound. The temperature of the rotary cooling drum needs to be 20 ° C. or lower, preferably 10 ° C. or lower. If the temperature of the rotary cooling drum is higher than 20 ° C., the film cannot be peeled off from the cooling drum.

  When the film is scraped off, it is preferable to hold a release paper between the films. By blocking the release paper, blocking after scraping can be prevented. Examples of the release paper include those obtained by applying polyethylene, polypropylene, silicon, etc. to known paper, polypropylene films, polyethylene films, etc. Especially if the film can be easily peeled off from the copolyester film adhesive material after film formation. It is not limited.

  The screw diameter of the extruder is appropriately selected, and the polymer melting temperature is appropriately selected within a temperature range of (Tm + 100 ° C.) or less. Further, the discharge amount of the resin is appropriately selected depending on the balance between the cooling rate and the discharge amount.

  In the present invention, a film obtained by extruding onto a rotary cooling drum and quenching is then stretched at a temperature of (Tg-10) to (Tg + 70) ° C. at a magnification of 1.1 to 5.0 times in the machine direction. The film may be stretched in the transverse direction at a magnification of 1.1 to 5.0 times. Stretching improves the high elongation, elastic modulus, dimensional stability, and the like of the film adhesive material, and blocking between films may be prevented depending on the composition of the copolyester.

The stretched film may be heat-set at a temperature not exceeding the melting point for 1 to 60 seconds. By heat fixing, the dimensional stability of the film can be improved.
If the heat setting temperature exceeds the melting point, the film melts, which is not preferable. Also, if the heat setting time is less than 1 second, the effect of heat setting is hardly exhibited, and if it exceeds 60 seconds, the film may stick to the roller or the film may melt, which is not preferable.

  In the present invention, the copolyester film adhesive material may be subjected to a surface treatment by corona discharge treatment, surface hardening treatment, plating treatment, coloring treatment, or various coating treatments, if necessary.

The present invention will be specifically described below with reference to examples.
(1) Number average molecular weight of copolymerized polyester The number average molecular weight is determined by GPC analysis (liquid feeding unit LC-10ADvp type and UV-visible spectrophotometer SPD-6AV type manufactured by Shimadzu Corporation), detection wavelength: 254 nm, solvent: Tetrahydrofuran, polystyrene conversion).
(2) Tm and Tg of copolymer polyester
Using a copolymerized polyester 10 mg as a sample, a DSC (Differential Scanning Calorimetry) device (DSC7 model manufactured by PerkinElmer Co., Ltd.) is used to measure at a temperature rising rate of 10 ° C./min. The peak temperature of the endothermic peak in the 1st scan Was defined as Tm, and an intermediate value between two bending point temperatures derived from the glass transition in the temperature rise curve of the 2nd scan was defined as Tg.
(3) Composition of copolyester
^{It determined by 1} H-NMR analysis (manufactured by Varian, 300 MHz).
(4) Thickness of film adhesive material The thickness of the film adhesive material was measured using a digital micrometer made by SONY.
(5) Heat seal strength (N / 15mm)
The film obtained in the present invention was sandwiched between PVC films having a thickness of 100 μm and heat sealed at a temperature of 150 ° C. and a pressure of 0.2 MPa for 1 second to prepare a sample having a width of 15 mm and a length of 100 mm. The sample was peeled off at a peeling speed of 300 mm / min according to JIS K-6854 using an autograph manufactured by Shimadzu Corporation, and the peak value of the measured value was obtained as the heat seal strength. Less than 15 mm was set as x.
(6) Film wrinkle A film adhesive material having a length of 5 m was visually observed, and the case where the surface wrinkle was 10 or more was judged as ◯, the case where it was 5-9, Δ, and the case where 0-4 was found as x.

Copolyester A
A mixture of terephthalic acid 831 g (50 mol parts), isophthalic acid 415 g (25 mol parts), ε-caprolactone 285 g (25 mol parts) and butanediol 1217 g (125 mol parts) was stirred at 240 ° C. in an autoclave. The esterification reaction was carried out by heating for 3 hours. Next, 0.2 g of tetrabutylentitanate was added as a catalyst at 240 ° C., and the pressure of the system was gradually reduced to 13 Pa after 1.5 hours to carry out a polycondensation reaction. Polycondensation was performed until an appropriate viscosity was obtained, and the resultant was designated as copolyester A. The composition and characteristics are shown in Table 1.

Copolyester BF
The monomers used and the charged molar parts were changed, and the same operations as in the above-mentioned copolymer polyester A were carried out to obtain copolymer polyesters B to F. The composition and properties of the obtained copolyester are shown in Table 1.

Example 1
The sufficiently dried copolymer polyester A pellets were put into an extruder, and the molten resin was extruded from a T-die onto a rotary cooling drum cooled to 20 ° C. Thereafter, after passing through four rollers, 100 m was scraped off by a stripper with a release film (polypropylene film, manufactured by Tosero Co., Ltd., 50 μm) in between. The screw diameter of the extruder was 65 mm, and the polymer melting temperature was 160 ° C. The obtained film adhesive material had a thickness of 100 μm and a film width of 420 mm.

Examples 2-4, Comparative Examples 1-3
A film adhesive material was produced in the same manner as in Example 1 except that the type of copolymer polyester and the temperature of the rotary cooling drum were changed.

Example 5
95 parts by mass of copolymer polyester A sufficiently dried and 5 parts by mass of silica (average particle size: 4 μm) were kneaded with a twin-screw extruder to prepare pellets. A film adhesive material was produced in the same manner as in Example 1 except that this dried pellet was used.

Example 6 and Comparative Example 4
A film adhesive material was produced in the same manner as in Example 5 except that the type of copolyester or inorganic compound and the blending amount thereof were changed. In Example 6, calcium carbonate having an average particle size of 5 μm was used as the inorganic compound.

Example 7
A film having a thickness of 120 μm was produced in the same manner as in Example 1 except that the discharge amount of the extruder was changed, and this film was held by a clip of a flat simultaneous biaxial stretching machine at a temperature of 60 ° C. The film was stretched 3.0 times and 3.3 times in the transverse direction. Then, after heat-fixing at a temperature of 100 ° C., the transverse relaxation rate was set to 2%, and the film was cooled and scraped off with a scraper to obtain a film adhesive material having a stretched thickness of 12 μm.

Examples 8-10
A film adhesive material was prepared in the same manner as in Example 7 except that the types of the copolyester and inorganic compound, the blending amount thereof, and the stretching temperature were changed.

Comparative Examples 5-8
Production of a film was attempted in the same manner as in Example 7 except that the stretching temperature, the stretching ratio, and the heat setting temperature were changed.

  Table 2 shows the production conditions and characteristics of the film adhesive materials obtained in Examples and Comparative Examples.

In any of the production methods of Examples 1 to 10, a film adhesive material could be produced.
On the other hand, in the production method of Comparative Example 1, since the melting point of the copolyester was high, the heat sealing force could not be obtained at the bonding temperature of 150 ° C., and the properties as a hot melt adhesive were not exhibited.
In the production method of Comparative Example 2, the number average molecular weight of the copolyester was smaller than 10,000, and in the production method of Comparative Example 3, the temperature of the rotary cooling drum was high, so that the film could be peeled off from the roller. The film adhesive material could not be obtained.
In the production method of Comparative Example 4, since the content of the inorganic compound was large, in the production method of Comparative Example 5, the stretching temperature was low, and in the production method of Comparative Example 7, the draw ratio was high. Each film was torn and could not be stretched.
In the production method of Comparative Example 6, because the stretching temperature was high, and in the production method of Comparative Example 8, the heat setting temperature was high, so that the films melted and could not be stretched.

Claims (4)

  A copolymer polyester containing an inorganic compound of 5% by mass or less, having a number average molecular weight of 10,000 or more, a melting point of 70 to 150 ° C., and a glass transition point of 20 ° C. or less is heated and melted and cooled to 20 ° C. or less from the die. A method for producing a copolyester film adhesive material, which is extruded onto a rotating cooling drum and rapidly cooled.   The method for producing a copolyester film adhesive material according to claim 1, wherein the inorganic compound is silica or calcium carbonate.   A film obtained by extruding onto a rotating cooling drum and quenching is stretched at a magnification of 1.1 to 5.0 times in the machine direction at a temperature of (glass transition point −10) to (glass transition point +70) ° C., The method for producing a copolyester film adhesive material according to claim 1 or 2, wherein the film is stretched in the transverse direction at a magnification of 1.1 to 5.0 times. The method for producing a copolyester film adhesive material according to claim 3, wherein the stretched film is heat-set at a temperature equal to or lower than the melting point for 1 to 60 seconds.