JPH03143619A - Heat-shrinkable polyester film - Google Patents

Abstract

PURPOSE:To obtain a heat-shrinkable polyester film giving a beautiful finished external appearance free from whitening since the film has a sufficiently high heat-shrinkable factor and shrinks uniformly, by a method wherein 50-90 mol% of a constituent ingredient is made an ethylene terephthalate unit and a content of the whole diethylene glycol out of a composition is made 2.5-20 mol%. CONSTITUTION:A composition is constituted of polyethylene terephthalate and copolymer polyester, 59-90 mol% of constituent ingredient is comprised of an ethylene terephthalate unit and it is necessary that the same contains 2.5-20 mol% diethylene glycol. When the ethylene terephthalate unit becomes less than 50 mol%, heat resistance of a film is lowered, and when the same exceeds 90 mol%, unidirectional shrink properties are lowered. Partial whitening is generated when the film is heat-shrinked under a state where a quantity of diethylene glycol is less than 2.5 mol% and when the same exceeds 20 mol%, the heat resistance is lowered. Then the film obtained with an arbitrary method is stretched 2.5-7.0 times unidirectionally and 1.0-2.0 times in a right angle direction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of application for industry 1) Kokumyo is a heat shrinkable layer 1 which emits a characteristic particularly suitable for the field of packaging materials (for coating or bundling). Concerning polyester film (including sheets; the same applies hereinafter).

In particular, it relates to a polyester film that gives a beautiful (1: tight) appearance without partially whitening the heat-shrinked film.

(Traditional Fujutsu) Tubular bodies made of heat-shrinkable PL brass tink film are used, for example, for 8 pilgrims, bottles (including plastic bottles), r+, rod-shaped objects (pipes, rods, wood, ftr
The push rod-shaped body)', da (hereinafter referred to as yōjiba) is used for binding purposes, especially the cap of τ, the k1 part, and covers part or all of the body part, and is used for marking stones, In addition to being used as a primary purpose, it is also used to make integrated packaging such as boxes, bottles, boards, sticks, notebooks, etc., or to tightly adhere it to the packaged items such as skin packs. It is widely used in the field of packaging, etc., and is expected to expand into applications that utilize shrinkage stress.

Conventionally, heat-shrinkable Y foils made of polyvinyl chloride, polystyrene, polyethylene, or hydrochloric acid rubber snow have been used for the above-mentioned purposes, and this has been made into a tube shape. was wrapped and heat-shrinked.

However, these films have a drawback that they have poor heat resistance Pl:, and when subjected to boiling or retort processing, they melt or burst, making it impossible to maintain the film-like structure.

In applications that require printing in the center, there is a small 1111 ＋
There is also the problem that even if the printing is successful, the film may shrink (shrinkage) and cause a printing pinch. On the other hand, tubes using polyester heat-shrinkable films have been made in the past, but it has not been possible to increase the heat-shrinkage rate in the rare direction. Moreover, there is a drawback in that it is impossible to reduce the thermal contraction in the direction orthogonal to the direction indicated, making it difficult to develop the above-mentioned applications.

These drawbacks are discussed, for example, in JP-A-163-156833.
As suggested in 7p5, this problem can be solved by adjusting the composition of the raw material polyester resin. However, the film obtained by this method also For example, when shrinking with hot air, there are parts that shrink sufficiently and parts that shrink insufficiently, which tends to cause mottled patterns (shrinkage spots) on the surface of the film. There is a drawback that parts become white and the appearance of the product becomes 11i.

(Problems to be solved by the invention) The present invention solves the conventional problems described in 1-1,
The purpose is to provide a heat-shrinkable tZC polyester film that has a sufficiently large heat-shrinkable size and shrinks uniformly, so that it does not partially whiten and has a beautiful 1-tank appearance. It is to be.

(Means for solving the problems) The non-shrinkable polyester film of the present invention contains polyethylene terephthalate and at least two diethylene glycols.
, 5 to 50 mol% of the composition with polymerized polyester, 50 to 90 mol% of the constituent components are ethylene terephthalate units, and the total diethylene glycol-containing paper in the composition is 2.5 to 50 mol%. It is a filter consisting of 20% by mole, and has a heat shrinkage rate of 30% or more in hot air at 100° C. at a predetermined strength of the film, and an L-type film is quickly formed due to the film's predetermined strength.

The composition of the present invention is composed of polyethylene terephthalate and a medium-white polyester.
It is necessary that 90 mol % consists of ethylene terephthalate units and 2.5 to 20 mol % of diethylene glycol is contained.

When the ethylene terephthalate unit reaches 50 moles, the heat resistance of the film decreases and the boiling process F11 with high heat resistance is used.
This is undesirable because it will not be able to withstand retort treatment and the manufacturing cost will be high.

On the other hand, if it exceeds 90 mol%, the shrinkage properties of the heat-treated 11. If the time is shortened, for example, if the bottle is coated, it will cause the phenomenon of loosening in the 11th part due to the killing process.
Not good.

In addition, when the diethylene glycol i11 was 2.5 mol% in Songman, when the film was heat-shrinked, the shrunk film t,
This is not desirable because it causes partial whitening and the appearance of the product becomes uneven. On the other hand, if it exceeds 20%, the film's stability tzh1, especially its weather resistance, will be low, or its resistance, Qt'l will be low, and it will not be able to withstand boiling processing and retort escape. I don't want to whisper.

There is also the problem that the degree of blueness increases.

3 to 10 mol % is particularly dangerous.

In the present invention, the composition described above is composed of polyethylene terephthalate and a copolymerized polyester, and at least 2.5% of diethylene glycol is contained as the copolymerized polyester.
It is characterized by using a material containing ~50 mol%.

・The copolymer resin on the crotch is melted 1. (Because of the low resin drying A and Q, it is difficult to handle, so it is better to use polyethylene terephthalate.) Since it is produced in small numbers and the manufacturing cost is at a woman's price, there is an advantage in using polyethylene terephthalate even in 71.j.

Normally, polyesters containing ethylene terephthalate units are incorporated into the produced polyester by a condensation reaction of ethylene glycol during the production process, even if diethylene glycol is not added during production.

The content of the ethylene terephthalate unit varies depending on the polyester manufacturing method, manufacturing conditions, and the catalyst used in the polyester.
In the case of polyethylene terephthalate, which is 1.0 to 2.5 mol %, the products currently on the market are 1.0 to 2.5 mol %. Also, for heat shrinkable polyester films, for example, JP-A 0? (Example 1 of No. 83-150331 discloses that a resin containing 2 mol % of diethylene glycol is used.

The copolymerized polyester of the present invention contains diethylene glycol h1. A significant feature is the use of a larger amount in the range of 2.5 to 50 mol%.

Control of the diethylene glycol content (T ftt) of the [0000] polyester may be carried out by optimizing the production conditions and catalyst, or by adding diethylene glycol to the transesterification reaction 11, i;
This may be done by adding t.

A method of adding a predetermined amount of I, 1 is particularly preferred.

Diethylene glycol in polyethylene terephthalate is not particularly limited, and can be set to α as long as the total diethylene glycol content of the composition is within the range of 2.5 to 20 mol%.

It may be 2.5 mol% or less, or it may be 2.5 mol% or more. It is economical and appropriate to use 2.5 mol% or more of the material produced in humans.

The co-polyester of the present invention is not particularly limited as long as it contains units other than ethylene terephthalate units. ] (Acid components other than terephthalic acid used in the composite polyester include isophthalic acid, phthalic acid,
2,6-naphthalene dicarboxylic acid A, 9 naphthalene dicarboxylic acids, 4゜4'dicarbonicarboxylic acid S.
Dicarboxy-7 biphenyls of
t-substituted dicarboxylbiphenyls, 1,1.3-1-lmethyl-3-phenylindene-4,5-dicarboxylic acid and its substituted products, 1,2-diphenoxyethane-4,
4'-dicarboxylic acid and its substituted heavy aromatic dicarboxylic acids, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sepacic acid, bimeric acid, speric acid, undecanoic acid, dodecanedicarboxylic acid, brasilin acids, alicyclic dicarboxylic acids such as tetradecanedicarboxylic acid, tabucic acid, nonadecanedicarboxylic acid, tocholine dicarboxylic acid, and substituted products thereof, alicyclic dicarboxylic acids such as 4.4' dicarboxycycloexane, and their 1d
Potatoes are mentioned.

Glycol components other than ethylene glycol and ethylene glycol used in the polyester include triethylene glycol, propylene glycol, butanediol, 1.6-hexanediol, 1. t
o-decanediol, neopentyl glycol, 2-methyl-2-ethyl-1,3-propanediol, 2-diethyl-1,3-propanediol, 2-ethyl-2-
Fatty acid diol M such as n-butyl-1,3-propanediol, 1. :lE/Chlohexanedimetatool 1
．． Alicyclic diols such as 4-cyclohexanedimethanol, 2,2-bis(4'-β-hydroxynidoxine phenyl)propane, bis(4'-β-hydrokine ethoxyphenyl) sulfone-specific bisphenol compounds Examples include ethylene oxide adducts and aromatic diols exclusively for xylylene glycol.

These (combined use of one or more polymeric components) are problematic in the sense that they balance the properties of the heat-shrinkable film. These copolymer components can be selected as film special features, economy t'l:τ, and (zukiko 5c).

These JI:, il'i combination polyesters can be produced by conventional polyester production methods. For example, a direct esterification method in which a dicarboxylic acid component is directly reacted with a glycol component to perform polycondensation; It is prepared by transesterification method. Preparation may be carried out in both quarterly and continuous manner.

Further, if necessary, lubricants such as titanium dioxide, silica, kaolin, and carbonate may be added. Toryo 1 da can also be added as an agent, UV protection +lz agent, or blue leveling agent. In addition, the hardness of the film J^ as a material is 0.50 to 1.3 rl (!/g).

Using such polymers, stretching methods and calendar methods (r,
, the film obtained by the CC method was 1; 11 and 2.5.
Stretch from 1.0 times to 7.0 times, preferably from 3.0 I The film is stretched 1.1 to 1.8 times. The stretching to the initial force 1 is carried out to increase the contraction 11, I, and the first one] 11J and ++: 1. Stretching in the unidirectional direction is extremely effective in solving the poor impact resistance and tear resistance t'l of films stretched in one direction.

However, when stretched more than 2.0 times, the main shrinkage direction is 1.
;;] and the non-shrinkage of the right angles 1; 11 become too large, and the finished product becomes wavy. To suppress this attack,
It is recommended that the aged fresh 1st be 15% or more, preferably less than 8 to 19%, and in the middle or less than 7%.
Recommended. There is no particular restriction on the first stage of stretching, and methods such as roll stretching, long gap stretching, and tenter stretching are applicable, and it does not matter whether the shape is flat or tubular.

The stretching may be carried out 1'1-by successive biaxial stretching, simultaneous biaxial stretching, multiple stretching, or a combination thereof. In addition, the film of the present invention is stretched, for example, along the longitudinal axis, the transverse axis, and the longitudinal and transverse directions, but in particular, in biaxial stretching, stretching in the longitudinal and transverse directions is performed first. Suitsugu 2nd stretch has a 1" effect, and that 1llri!? It may be done first. Same 1
1. When using the biaxial stretching method, the stretching order may be either simultaneous in the vertical direction and horizontal direction, vertical direction first, or horizontal direction first. Heat setting in these stretching processes is carried out depending on the conditions, but the
In order to do this, it is recommended to pass through a heating zone of 30 to 150"C for about 1 to 30 seconds. Either before or after Pp. In particular, it is recommended to stretch in the direction of 1 and relax in the direction of contraction (I:, 11 [angular direction is the same) with respect to the direction of contraction. It would be better not to extend it.

In order to achieve the preferable characteristics of the present invention, it is necessary to apply not only the stretching ratio described in (a) but also the iK composite composition's average glass transition temperature (Tg) of 114 degrees or higher, for example, Tg + 8
Stretching under r-heat at about 0°C is also an effective step. In particular, ■ Mika 1; 11 stretching (-1 mo shrinkage direction), note F (! 7M degree is perpendicular to the direction and the same right heat shrinkage;
1 at ±25°C. ．． Frame it with 1, which brings the minimum plant to 1 degree range, and it is 'TIe. After stretching, the film is stretched to 1' or 1', and then the film is stretched while being stressed.
) The shrinkage characteristics after i+ are better and more stable.

The orientation coefficient of the film obtained in this way is 1 ooxt
Anything less than o-” is suspicious.+rii introversion coefficient is t
This is because if you soften the ``ooxio-'', it will be easier to break against an impactful external force, and even the slightest trauma will cause it to break.・For Nk+i funeral, it will be 15X10-'' ~ 1
The 60
10-" In the southeast, there is a lack of cram school contraction condolence and contraction strength between vertical lines, and when 160 Sexuality is low.

The folding index is 15XIO-' to 160X10-''.
In 1 To disease, the contraction force in the E contraction direction and the contraction stress become low. On the other hand, when 160 x 10-" is mixed, it will tear due to external damage, and the impact strength will be low, resulting in poor durability.
The norm is childish.

The shrinkage ↑ No. 1 polyester film of the present invention obtained in this way has, for example, 3 l I B at 40°C.
Even if the film is shrunk by applying no air after storage, no partial 1'1 conversion occurs in the film. The surface of the film of the present invention may be printed if necessary. By heat shrinking, it can be used for various scale applications such as wave crest, prefectural east, and exterior scales.

(Example) Examples are described below or used in the examples. 1jllll
The method for determining this is as follows.

1. Shrinkage: The distance between the sample marks was 20011IIl, the film was cut into 115mm, and the film was heated for about 1 minute using hot air at 100°C for measurement.

2 Heat shrinkage residual cardiac force maintained 0 open (50% relaxation 11.'l'
) Using a Tennron, collect a sample piece with a length of 20 meters and a length of 150 meters, and fill the fill 11 of the sample piece with a length of 100 m+.
Mark the marked line of w, align the marked line of lOO open exactly with the L dochanok set at 50 degrees, apply blue, and treat in hot air of lOO'C until the contractile cardiac force reaches O. 11! Ask for distance between f.

3. After storing the rolled film obtained by partial whitening film formation at 40° C. for 3 IJ, the film was cut into pieces with a diameter of 230 mm and put into a tube-forming device to form a tube-like body. The tubular body was cut to a length of 140 mm, placed over a single-serve size glass bottle, and heated at 130° C./Ilm 1.
It was heat-shrinked for 5 seconds with hot air under χ.

Applicable! The deeply shrunk film is observed with the naked eye, and the i1jHHE of the r1-formed portion is determined.

4. Diethylene glycol-containing ('f'!-it) polyester is decomposed with methanol at high temperature and high pressure, and then determined by gas chromatography.

Example 1 Polyester "A a l-,j'J" was prepared by adding diethylene glycol to polyethylene terephthalate containing 2.0 mol% of diethylene glycol and terephthalic acid/sebacic acid ethylene glycol/diethylene glycol/ Neopentyl glycol = 85/15//40/10150 (molar ratio) J!:, +T1'' synthetic polyester 80%
: Blend uniformly with a ton fit ratio of 20 and heat at 300″C.
The film was melted at 1111 mm and a J9: rice stretched film with a thickness of 180 tt was obtained. The film was stretched 1.2 times in the longitudinal direction,
Next, the film was stretched 4.1 times in the transverse direction, and then cooled by stretching by about 20% in the transverse direction to obtain a 40-stretched film. Table 1 shows the properties 6III of the obtained stretched film.

The film obtained by the method of the present invention has excellent shrinkage properties and is of l'j71 quality, with no partial whitening occurring in the shrunk film.

Comparative Example 1 Same method as Example 1 except that the diethylene glycol content of the copolymerized resin was changed to 2.0 mol%. Table 1 shows the properties of the stretched film obtained above.

The film obtained in this comparative example had excellent directional shrinkage of 0.
However, partial whitening occurs in the Kr part of the bottle where the shrinkage rate of the shrunk film is high, which is less of a disaster.

Comparative Example 2 Table 1 shows the properties of a stretched film obtained in the same manner as in Example 1 except that polyethylene terephthalate was not used and only the copolymer resin was used.

The film obtained in this comparative example had an excellent direction shrinkage P.
L is (rt), and partial conversion to 11 does not occur in the shrunk film, but the retention of residual stress during heat treatment is short (for example, when it is covered with a bottle, it is killed) This solves the problem that II causes a special phenomenon in which the kJ section becomes loose.

Comparative Example 3 Table 1 shows the characteristics of a stretched film 1 obtained in the same manner as in Example 1 except that only polyethylene terephthalate was used without using a copolymerized resin.

The film obtained in this comparative example was: 1i+] 1a
The equipment τf is inferior in terms of l'L, partial whitening and residual ratio, and force retention of 11 yen.

Examples 2 to 10 Table 1 shows the characteristics of stretched films obtained in the same manner as in Example 1 using the polyesters shown in Table 1. The films obtained in these examples are all of high quality.

Comparative Example 4 Table 1 shows the properties of a stretched film obtained in the same manner as in Example 2, except that polyethylene terephthalate and J(polymerized polyester containing diethylene glycol) Gt was 2.0 mol %.

The film obtained in this comparative example is inferior in that whitening occurs partially in the shrunk film.

The following margin (effect of perforation 1R) Since the film of the present invention is constructed as shown in -1-,
It exhibits sufficient heat shrinkability for Tokusho, and is able to maintain beautiful and strong packaging in Enoki packaging and Kento packaging.
In addition, the printing pinch stability, whiteness, heat 1/L of the same special effects can be improved by 41, and the film produced by the distributor 1 does not cause partial whitening phenomenon and can be widely used. What a minute! Does light have excellent utility value in FF? 'l! can do.

Special+h applicant: Toyo Shuso Co., Ltd.

Claims (1)

[Claims] 1) Consisting of a composition of polyethylene terephthalate and a copolyester containing at least 2.5 to 50 mol% of diethylene glycol, 50 to 90 mol% of the constituent components.
consists of ethylene terephthalate units, and the total diethylene glycol content in the composition is 2.5 to 20
% by mole, and has a heat shrinkage rate of 30% or more in one predetermined direction of the film in hot air at 100°C.