JPH07108563B2 - Thermoplastic resin film laminate and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a transparent and excellent antistatic thermoplastic resin film laminate and a method for producing the same.

(Prior Art) As is well known, thermoplastic resin films such as polyester, polyamide, polypropylene, etc., especially polyester films, especially polyethylene terephthalate film, have a high degree of crystallinity, excellent transparent gloss, mechanical properties, chemical resistance and heat resistance. Therefore, it is rapidly used for a wide range of applications year after year.

However, since a general polyester film has a high degree of electrical insulation, it has a drawback that static electricity is likely to be generated and accumulated and various troubles due to electrostatic damage are caused. For example, in the film forming process, printing, adhesion, bag making, packaging, and other secondary processing steps, winding around a roll, electric shock to the human body, lowering of work efficiency such as difficulty in handling, and occurrence of print whiskers. , Which may cause a decrease in product value such as dirt on the film surface. As a method of preventing such electrostatic damage, there are generally a method of kneading an antistatic agent into a resin to form a film, and a method of applying the antistatic agent to the film surface. For polyester film,
This so-called kneading type antistatic treatment method exhibits an antistatic effect by the antistatic agent bleeding from the inside of the film to the surface, whereas the high second-order transition temperature of the polyester resin causes the film to form after film formation. At around room temperature, the antistatic agent does not exude to the film, but on the other hand, due to the high film forming temperature conditions and the high reactivity of the polar groups of the polyester itself, the incorporation of the antistatic agent has It is difficult because there are problems such as deterioration of the polymer during film formation, coloration and deterioration of physical properties. In particular, in the case of a biaxially stretched polyester film, the antistatic agent on the surface of the film often escapes and disappears during the stretching process, and in many cases no antistatic effect is exhibited at all, and most of the antistatic agents are blended with the polyester film. Therefore, the transparency of the film is extremely lowered, and it is difficult to put it into practical use. Further, the usual method of applying the antistatic agent to the film surface requires extra processing steps, which is economically disadvantageous.

(Problems to be Solved by the Invention) As a result of diligent research and efforts to solve the problem in the conventional technique, that is, the difficulty of imparting antistatic property without impairing transparency, The present invention has been completed.

(Means for Solving Problems) That is, the present invention is based on (A) all dicarboxylic acid components.
Containing a mixture of a water-insoluble polyester copolymer formed from a mixed dicarboxylic acid component and a glycol component containing 5 to 15 mol% of a metal sulfonate-containing dicarboxylic acid, and (B) a mixture of a cocondensate represented by the following formula layers are at least laminated on one surface a thermoplastic resin film laminate HOR _1, characterized by comprising O _n R ₂ O _m H (where, n, m is an integer of 6~1200, R _1, R ₂ carbon Number 1-4
Alkylene group or arylene group. R ₁ ≠ R ₂ and
(A) one or more of R ₁ and R ₂ has a carbon number of 3 or more) and the melt-extruded unstretched thermoplastic resin film or uniaxially stretched thermoplastic resin film (A) all dicarbon A water-insoluble polyester copolymer formed from a mixed dicarboxylic acid component containing 0.5 to 15 mol% of a sulfonic acid metal group-containing dicarboxylic acid with respect to the acid component and a glycol component, and (B) a cocondensate represented by the following formula The method for producing a thermoplastic resin film laminate is characterized in that a coating solution containing the mixture of above is applied and then biaxially stretched or uniaxially stretched.

_{HOR 1 O n R 2 O m} H ( where, n, m is an integer of 6~1200, R _1, R ₂ are carbon atoms 1 to 4
Alkylene group or arylene group. R ₁ ≠ R ₂ and
Either one of R ₁ and R ₂ is an alkylene group having 3 or more carbon atoms or an arylene group) The polyester copolymer (A) of the present invention comprises 0.5 to 15 mol% of a sulfonic acid metal group-containing dicarboxylic acid and a sulfonic acid. It is a substantially water-insoluble polyester copolymer obtained by reacting a mixed dicarboxylic acid with 85 to 99.5 mol% of a dicarboxylic acid containing no metal base with a glycol component. Substantially water-insoluble means that the polyester copolymer does not dissipate in hot water even if the polyester copolymer is stirred in hot water at 80 ° C. The weight reduction of the polyester copolymer after the stirring treatment in 80 ° C. hot water for 24 hours is 5% by weight or less.

As the above-mentioned carboxylic acid metal sulfonate-containing dicarboxylic acid,
Examples thereof include metal salts such as sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid and 5 [4-sulfophenoxy] isophthalic acid, and particularly preferred is 5-sodium. Sulfoisophthalic acid and sodium sulfoterephthalic acid.
These sulfonic acid metal base-containing dicarboxylic acid components,
0.5 to 15 mol% with respect to the total dicarboxylic acid component, 15
If it exceeds 0.5% by mole, the water resistance of the polyester copolymer is remarkably lowered, and if it is less than 0.5% by mole, the dispersibility in the inert particles is remarkably lowered.

The dispersibility of the polyester copolymer in water varies depending on the copolymerization composition, the type of water-soluble organic compound, the compounding ratio, etc., but the dicarboxylic acid containing a metal sulfonate group does not impair the dispersibility in water. A small amount is preferable.

As the dicarboxylic acid containing no metal sulfonate base,
Aromatic, aliphatic and alicyclic dicarboxylic acids can be used.
Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid and the like. These aromatic dicarboxylic acids preferably account for 40 mol% or more of the total dicarboxylic acid components. If it is less than 40 mol%, the mechanical strength and water resistance of the polyester copolymer will decrease. Examples of the aliphatic and alicyclic dicarboxylic acids include succinic acid, adipic acid, sebacic acid,
1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid,
Examples include 1,4-cyclohexanedicarboxylic acid.
Addition of these non-aromatic dicarboxylic acid components may enhance the adhesive performance in some cases, but generally reduces the mechanical strength and water resistance of the polyester copolymer.

The glycol component to be reacted with the mixed dicarboxylic acid is an aliphatic glycose having 2 to 8 carbon atoms or an alicyclic glycol having 6 to 12 carbon atoms, specifically, ethylene glycol, 1,2-propylene. Glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol , P-xylylene glycol, diethylene glycol, triesylene glycol and the like. Examples of the polyether include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.

The polyester copolymer is obtained by usual melt polycondensation. That is, the above-mentioned dicarboxylic acid component and glycol component are directly reacted to distill off water for esterification, and then a direct esterification method is carried out to carry out polycondensation, or dimethyl ester of the above-mentioned dicarboxylic acid component is reacted with glycol component to produce methyl alcohol. Can be obtained by a transesterification method or the like in which distilling is conducted to perform transesterification and then polycondensation is performed. In addition, solution polycondensation, interfacial polycondensation, etc. are also used, and the polyester copolymer of the present invention is not limited by the polycondensation method. In order to obtain an aqueous dispersion of the above polyester copolymer, it is necessary to disperse it in water together with the water-soluble organic compound. For example, the above polyester copolymer and a water-soluble organic compound are added in an amount of 50 to 240
Mixing in advance at ℃, add water to this mixture and stir to disperse, or conversely, add the mixture to water and stir to disperse, or coexist with the polyester copolymer, water-soluble organic compound and water There is a method of stirring at 40 to 120 ° C.

The water-soluble organic compound is an organic compound having a solubility in water of 1 at 20 ° C. of 20 g or more, and is specifically an aliphatic or alicyclic alcohol, ether, ester, or ketone compound, such as methanol, ethanol, or the like. Isopropanol, monohydric alcohols such as n-butanol, glycols such as ethylene glycol and propylene glycol, glycol derivatives such as methyl cellosolve, ethyl cellosolve, n-butyle cellosolve, ethers such as dioxane and tetrahydrofuran, ethyl acetate and the like. Ketones such as esters and methyl ethyl ketone. These water-soluble organic compounds may be used alone or in combination of two or more. Of the above compounds, butyl cellosolve and ethyl cellosolve are preferable in view of dispersibility in water and coatability on a film.

The blending weight ratio of the above-mentioned (A) polyester copolymer, (C) water-soluble organic compound and (D) water is (A) / (C) = 100/20 to 5000 (C) / (D) = 100 / It is important to satisfy 50 to 10,000. Less water-soluble organic compound than polyester copolymer (A) / (C) 100 /
If it exceeds 20, the dispersibility of the aqueous dispersion will decrease. In this case, the dispersibility can be assisted by adding a surfactant, but if the amount of the surfactant is too large, the adhesiveness and the water resistance will be deteriorated. Conversely, (A) / (C) is 100 /
If it is less than 5,000 or (C) / (D) exceeds 100/50, the amount of water-soluble organic compound in the aqueous dispersion will be large and there is a risk of explosion due to the solvent during in-line coating. Therefore, it is necessary to take measures against explosion, and it is necessary to consider the compound recovery because it will cause environmental pollution and cost. When (C) / (D) is less than 100/10000, the surface tension of the aqueous dispersion becomes large, the wettability to the film decreases, and coating spots tend to occur.

The (B) co-condensed polyether to be mixed with this dispersion has an optimum molecular weight of 1,000 to 100,000 and has a structure represented by the following formula.

_{HOR 1 O n R 2 O m} H ( where, n, m is an integer of 6~1200, R _1, R ₂ are carbon atoms 1 to 4
Alkylene group or arylene group. R ₁ ≠ R ₂ and
Either one of R ₁ and R ₂ is an alkylene group having 3 or more carbon atoms or an arylene group. In the above formula, it is more preferable that the segments of R ₁ O and R ₂ O are randomly condensed.

Further, among those having the structure of the above formula, polyoxyethylene-polyoxypropylene condensate is particularly preferable,
A molecular weight of 1000 to 3000 and a copolymerization composition of 80 to 5/20 to 95 are good, and a condensate structure of a random copolymer shows better antistatic properties. These polyoxyethylene-polyoxypropylene condensates are used by mixing in the polyester copolymer (A) in an amount of 5 to 30% by weight. If the mixing amount of the polyoxyethylene-polyoxypropylene condensate is too small, the antistatic property will not be exhibited, and if it is too large, there will be problems in coatability and film blocking will occur.

In addition, the combined use of these polyoxyethylene-polyoxypropylene condensates with other antistatic agents such as anionic antistatic agents and inert particles has the effect of reducing the antistatic effect of the polyoxyethylene-polyoxypropylene condensates. There is nothing to prevent.

The aqueous dispersion of the polyester copolymer thus obtained is applied to the polyester film by a coating method, which may be an unstretched film obtained by melt-extruding the polyester film, or a uniaxially stretched film or a biaxially stretched film. However, it is difficult to apply it to a biaxially stretched film because the film is wide and the traveling speed of the film is fast, so it is difficult to apply it uniformly. Is more preferable.

The coating amount of the aqueous dispersion applied to the polyester film by the coating method is 0.01 to 5 g / m ² as the polyester copolymer as the amount present on the film after biaxial stretching.
If the coating amount is less than 0.01 g / m ^2, the force for fixing inert particles and the like will be weakened and the durability will be poor. On the other hand, if it is applied at 5.0 g / m ² or more, the slip property will deteriorate.

The polyester film obtained by the method described above is excellent in transparency and antistatic property.

Further, by applying a corona discharge treatment to the polyester film before coating the aqueous dispersion of the polyester copolymer, the coatability of the aqueous dispersion is improved, and the polyester film and the polyester copolymer coating film The adhesive strength between and is improved.

Further, the polyester copolymer layer after coating or after biaxial stretching is subjected to corona discharge treatment, corona discharge treatment in a nitrogen atmosphere, ultraviolet irradiation treatment, etc. to improve wettability and adhesiveness of the film surface. be able to.

The coating polyester film produced by the above method is used for magnetic tape base film, label sticker base film, chemical mat base film, overhead projector film, food packaging film, and other applications. You can do it.

(Example) In the examples, parts and% are based on weight.

Example 1 (1) Production of polyethylene terephthalate Lead hydroxide pbO.pb (OH) in 200 ml of ethylene glycol
₂ 2.2 g (pb0.95 × 10 ^-2 mol) was dissolved and GeO was added to this solution.
₂ 2.0 g (1.9 × 10 ^-2 mol) was added and the mixture was heated under reflux at the boiling point of ethylene glycol at 197 ℃ to obtain a clear solution in about 30 minutes. Next, polyethylene terephthalate was produced using this solution as a polycondensation catalyst. 620 parts of dimethyl terephthalate, 480 parts of ethylene glycol, zinc acetate _{Zn (OAc) 2 · 2H 2} O0.036 parts taken transesterification reactor as an ester exchange catalyst, ester exchange reaction than 0.99 ° C. 230
The temperature was gradually raised to 0 ° C., and the distillation of methanol was completed in 120 minutes. Then transfer the contents to a polycondensation device,
As the polycondensation catalyst, 2.7 parts of the above catalyst solution was added and the temperature was gradually raised and the pressure was reduced, followed by 1 hour, at 280 ° C., and polycondensation reaction under high reduced pressure of 0.5 mmHg for 25 minutes to obtain a polymer. It had an intrinsic viscosity of 0.63 and a melting point of 262 ° C.

(2) Production of Aqueous Dispersion of Polyester Copolymer 117 parts (49 mol%) dimethyl terephthalate, 117 parts (49 mol%) dimethyl isophthalate, 103 parts (50 mol%) ethylene glycol, 58 parts (50 mol%) diethylene glycol
Mol%), 0.08 part of zinc acetate and 0.08 part of antimony trioxide are heated in a reaction vessel to 40 to 220 ° C. for a transesterification reaction for 3 hours, and then 9 parts of 5-sodium sulfoisophthalic acid (2 mol%) are added. After the addition, the esterification reaction was conducted at 220 to 260 ° C. for 1 hour, and the polycondensation reaction was further performed under reduced pressure (10 to 0.2 mmHg) for 2 hours to obtain a polyester copolymer having an average molecular weight of 18,000 and a softening point of 140 ° C. This polyester copolymer
150 parts of 300 parts and 140 parts of n-butyl cellosolve in a container
Stir at 70 ° C for about 3 hours to obtain a uniform and viscous melt, and gradually add 560 parts of water to this melt, and after about 1 hour, disperse the water in a uniform pale white solid content of 30%. A liquid was obtained, and 8 parts by weight of the polyoxyethylene-polyoxypropylene cocondensate shown in Table 1 was added to the polyester copolymer in an amount of 4500 parts of water and 45 parts of ethyl alcohol.
00 parts was added and diluted to obtain a coating liquid having a solid content concentration of 3%.

(3) Production of coat film The polyethylene terephthalate produced in (1) is added to 280 to 3
Melt extruded at 00 ℃, cooled with a 15 ℃ chill roll to give a thickness of 10
An unstretched film of 00 microns was obtained, and this unstretched film was stretched 3.5 times in the machine direction between a pair of rolls at different peripheral speeds of 85 ° C, and the above-mentioned coating solution was applied by an air knife method to 70 ° C.
Dry with hot air, then in a tenter at 98 ° C laterally 3.5
The film was double-stretched and heat-set at 200 to 210 ° C. to obtain a biaxially stretched coating polyester film having a thickness of 100 μm. The results are shown in Table 2.

In Table 1, TPA is terephthalic acid equivalent, IPA is isophthalic acid equivalent, SSI is 5-sodium sulfoisophthalic acid, EG is ethylene glycol, DEG is diethylene glycol, NPG.
Is neopentyl glycol, EO is polyoxyethylene,
PO is polyoxypropylene.

Example 2 A biaxially stretched film was prepared in the same manner as in Example 1 except that NPG was used instead of DEG in Example 1 and the mixing amount of the polyoxyethylene-polyoxypropylene condensate into the polyester copolymer was changed. Got

Example 3 A biaxially stretched film was obtained in the same manner as in Example 1 except that the molecular weight, composition, and amount of the polyoxyethylene-polyoxypropylene condensate of the polyoxyethylene-polyoxypropylene condensate were changed.

Example 4 Example 1 was repeated except that the amount of SSI in Example 1 was increased, and the composition of the polyoxyethylene-polyoxypropylene condensate and the amount mixed into the polyester copolymer were changed.
A biaxially stretched film was obtained in the same manner as.

Example 5 The amount of SSI was increased in Example 1, and the molecular weight of the polyoxyethylene-polyoxypropylene condensate was further increased.
A biaxially stretched film was obtained in the same manner as in Example 1 except that the composition was changed.

Example 6 A biaxially stretched film was obtained in the same manner as in Example 1 except that the molecular weight of the polyoxyethylene-polyoxypropylene condensate was changed.

Example 7 Example 1 was repeated except that the molecular weight and composition of the polyoxyethylene-polyoxypropylene condensate were changed.
A biaxially stretched film was obtained in the same manner as.

Comparative Examples 1 and 2 A biaxially stretched film was obtained in the same manner as in Example 1 except that the SSI amount in Example 1 was added outside the scope of the claims.

Comparative Example 3 A biaxially stretched film was obtained in the same manner as in Example 1, except that the coating method of applying after biaxial stretching was applied in Example 1.

Comparative Example 4 A biaxially stretched film was obtained in the same manner as in Example 5 except that the structure of the polyoxyethylene-polyoxypropylene condensate was changed.

Comparative Example 5 A biaxially stretched film was obtained in the same manner as in Example 4, except that the amount of the polyoxyethylene-polyoxypropylene condensate mixed with the polyester copolymer was changed from the range defined in the claims. .

Comparative Example 6 A biaxially stretched film was obtained in the same manner as in Example 6 except that the mixing amount of the polyoxyethylene-polyoxypropylene condensate into the polyester copolymer was changed from the range defined in the claims. .

Comparative Example 7 A biaxially stretched film was obtained in the same manner as in Example 6 except that the composition of the polyoxyethylene-polyoxypropylene condensate in Example 6 was changed outside the scope of the claims.

Comparative Example 8 A biaxially stretched film was obtained in the same manner as in Example 2, except that the composition of the polyoxyethylene-polyoxypropylene condensate in Example 2 was changed outside the scope of the claims.

Comparative Examples 9 and 10 In Example 1, except that the molecular weight of the polyoxyethylene-polyoxypropylene condensate was changed outside the scope of the claims.
A biaxially stretched film was obtained in the same manner as in Example 1.

Comparative Example 11 A biaxially stretched film was obtained in the same manner as in Example 1 except that the polyoxyethylene-polyoxypropylene condensate was not added.

Haze in Table 2 was measured using a haze meter manufactured by Nippon Seimitsu Optical Co., Ltd. according to JIS K6714.

The blocking property is 8 when the coated surface and the uncoated surface are in close contact with each other.
Cut it to a size of 12 cm, sandwich it with two silicone rubber sheets, sandwich it with a glass plate, apply a load of 2 kg from the glass plate, and leave it in an atmosphere of 40 ° C and 80% RH for 24 hours. After that, the film was removed, and the blocking state between the films was visually judged, and 5% or less of the blocking area was marked with ◯, 5 to 20% was marked with Δ, and 20% or more was marked with x.

Regarding the coating method, after the coating liquid was coated, the state of the coated surface was visually judged, and those that caused repellency, unevenness, etc. were indicated by x, and those that did not occur were indicated by ◯.

For the coating film, apply Nichiban cellophane tape on the coated surface and peel it off so that the peeling angle is 180 °, then dye the coated surface with a dye that can dye only the laminated polyester, and peel the coating film. The presence or absence of The case where peeling did not occur at all in the coating film was indicated by ◯, and the case where even slight peeling occurred was indicated by x.

The surface resistance is the applied voltage with a Takeda Riken resistance measuring instrument.
It was measured under the conditions of 500 V, 20 ° C. and 65% RH. In Table 2, the method of the present invention exhibits good characteristics in terms of haze, blocking property, coatability, peelability of coating film, and surface resistance (antistatic property). However, when the amount of SSI is too small (Comparative Example 1), water dispersion of the polyester copolymer becomes impossible, and conversely, when the amount of SSI is too large (Comparative Example 2), blocking is likely to occur. Further, when the amount of the polyoxyethylene-polyoxypropylene condensate mixed with the polyester copolymer is large (Comparative Example 5), blocking is likely to occur,
On the contrary, when the amount is too small (Comparative Examples 6 and 11), the antistatic property is poor. Further, when the composition of the polyoxyethylene-polyoxypropylene condensate is out of the claimed range (Comparative Examples 7 and 8) or when the structure is block copolymerization (Comparative Example 4), good antistatic property is obtained. I can't get sex.

Furthermore, when the molecular weight of the polyoxyethylene-polyoxypropylene condensate is too small (Comparative Example 9), the antistatic property is poor, and conversely, when the molecular weight is too large, the haze becomes poor.
Further, it can be seen that when the coating method is off-line coating (Comparative Example 3), the coating film is easily peeled off.

(Effects of the Invention) As described above, the polyester film obtained by the method of the present invention can provide good antistatic property without causing peeling or blocking of the coating film.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Osamu Makimura 10-24 Toyocho, Tsuruga City, Fukui Prefecture Toyobo Co., Ltd. Research Institute Tsuruga Branch Hitomi Morita

Claims (2)

[Claims] 1. Amount of 0.5 to 15 relative to (A) all dicarboxylic acid components.
A layer containing a mixture of a water-insoluble polyester copolymer formed from a mixed dicarboxylic acid component containing mol% of a sulfonic acid metal group-containing dicarboxylic acid component and a glycol component and (B) a cocondensation product represented by the following formula: A thermoplastic resin film laminate characterized by being laminated on at least one side. _{HOR 1 O n R 2 O m} H ( where, n, m is an integer of 6~1200, R _1, R ₂ are carbon atoms 1 to 4
Alkylene group or arylene group. R ₁ ≠ R ₂ and
One of R ₁ and R ₂ is an alkylene group or an arylene group having 3 or more carbon atoms) 2. A non-stretched thermoplastic resin film melt-extruded or a uniaxially stretched thermoplastic resin film is coated on at least one side with 0.5 to 15 mol% of (A) all dicarboxylic acid components.
A coating solution containing a mixture of a water-insoluble polyester copolymer formed from a mixed dicarboxylic acid component containing a dicarboxylic acid containing a metal sulfonate and a glycol component and (B) a cocondensation product represented by the following formula: A method for producing a thermoplastic resin film laminate, which is characterized by further biaxially stretching or uniaxially stretching. _{HOR 1 O n R 2 O m} H ( where, n, m is an integer of 6~1200, R _1, R ₂ are carbon atoms 1 to 4
Alkylene group or arylene group. R ₁ ≠ R ₂ and
One of R ₁ and R ₂ is an alkylene group or an arylene group having 3 or more carbon atoms)