JPS6143676A - Adhesive composition - Google Patents

Abstract

PURPOSE:To provide the titled composition having excellent retort resistance, slippery, roll tightness, adhesivity, etc., by compounding a polyester ether block copolymer having a specific melting point with a particular polyester and a polyolefin at specific ratios. CONSTITUTION:The objective composition is composed of (A) 50-90(wt)%, preferably 55-80% polyester ether block copolymer having a melting point of >=100 deg.C (preferably 110-180 deg.C) and containing a polyester segment-constituting component forming a polymer having a melting point of 120-200 deg.C, (B) 5-30% polyester containing tetephthalic acid accounting for >=60% of the whole dicarboxylic acid component, and (C) 1-30% polyolefin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-adhesive composition having excellent properties such as retort resistance, blocking property, sliding property, double-wound property, and adhesive strength.゛As a thermal adhesive resin,
Ethylene/vinyl acetate resin, polyethylene, ionomer, copolyamide, copolyester, polyester ether, etc. are known and are used as adhesive resins in the form of hot melt, film, and coating.

Polyester and polyester ether adhesive resins have the following advantages compared to adhesives such as polyethylene and ethylene/vinyl acetate resins, such as superior heat resistance and adhesive strength with polyester films. Resins and compositions are known.

(1) Polyester, (2), t+! I ester ether, block copolymer, (3) polyolefin (1)
Or system 1 blended into (2) (4) (1) and (2)
), (5) a system in which a small amount of epoxy compound is added, etc.

The combination of a polyester ether block copolymer, a polyester, and a polyolefin has not yet been known as an adhesive composition.

These conventionally known adhesive resins (12 to (5
) also has the following drawbacks: (1), (2),
In the case of (4), there are problems with the tackiness and slipperiness of the adhesive resin surface, and there are disadvantages in that the processability is poor when handling the film. In order to improve this point, there is a method of adding inorganic fine particles, but if they are added in an amount sufficient to improve tackiness and slipperiness, the disadvantage is that the adhesive force decreases. In the case of (3), the dispersibility of the polyolefin is poor, and although the tackiness and slipperiness of the adhesive surface are improved, the adhesive force is reduced. (5) is exposed to high temperatures when melt-extruded into a film, so a gel-like substance is generated, which does not cause fish eyes, but also prevents uneven thickness and poor edge formability. Film formation cannot be performed. Furthermore, when the residence time is long, such as in a large extruder, the F pressure increases and eventually extrusion becomes impossible. Such a phenomenon is not improved at all even in compositions containing polyolefins such as polypropylene.

These adhesive resins are used in (-) coating # (b) film form, (0) hot melt form,
These stones have their advantages and disadvantages as follows.

That is, in (a), the adhesive layer can be made thin, but it is difficult to make it thick because of the sealing force. In addition, the film is difficult to handle due to the presence of many resins that are difficult to wash in solution and the adhesiveness and slipperiness of the coating group. In (b), a composite film in which an adhesive layer is laminated in the film forming process is common, but it is essential from the viewpoint of manufacturing cost to recycle the film waste generated during the film forming process. If waste is collected there, there is a drawback that the transparency and mechanical properties of the composite film are reduced. Therefore, in reality, scraps can hardly be recovered, resulting in high costs. On the other hand, conventional adhesive resin compositions have drawbacks such as poor lubricity of the film and easy blocking, making it difficult to handle, and when wound into a roll, the film tangles and cannot be unrolled.

In (O), in addition to the tackiness and slipperiness of the adhesive layer being a problem as in the case of (a), in the case of a blend system, the dispersibility of the composition is a problem.

As a result of studies aimed at improving these conventional polyester and polyester ether block copolymer adhesive resins and their drawbacks in use, the present invention was arrived at. That is, the present invention is a polyester ether block copolymer having a melting point of 100°C or higher and a melting point of 120 to 200°○ when the polymer is formed only from polyester segment components (abbreviated as Polymer A) 50 to 90wt1 and terephthalic acid accounts for at least 60% of the total dicarboxylic acid component.
m) Polyester (hereinafter abbreviated as Polymer B) accounting for 5 to 30 wt% or more and polyolefin (Polymer C)
It is a thermal adhesive composition consisting of 1 to 50wt-54 (abbreviated as ).

The heat-adhesive composition of the present invention has better film-forming properties such as castability when melt-extruded to form a film, compared to the above-mentioned (1) to (5).

There are no problems with adhesion or blocking, and it has good slip properties, so it significantly improves membrane permeability during unwinding and processing of film wound into rolls.

Furthermore, when wound into a roll, there is no seaming wrinkle compared to conventional products, so the roll appearance and flatness are good. In addition, regarding thermal adhesive strength, the adhesive strength after boiling and retort treatment is significantly lower than before treatment in the cases of (1) to (5), but almost no decrease is observed in the product of the present invention. On the contrary, it tends to improve.

Here, the polymer A mainly contributes to adhesive strength and is composed of reeds, polyester segments, and polyether segments, and has a melting point of 100°C or higher, preferably 110°C or higher.
180'O), which has a melting point of 120 to 200'O (preferably 160'
~190℃).

Typical examples of the polyester segment of this polyester-ether block copolymer are aromatic polyesters such as polytetramethylene terephthalate inphthalate copolymer and polyethylene terephthalate isophthalate copolymer.

Examples of dicarboxylic acids forming cholera polyester segments include tele/I/acid, isophthalic acid, adipic acid, sebacic acid, naphthalene dicarboxylic acid, dodecane dicarboxylic acid, and the like. Typical diols include tetramethylene glycol, ethylene glycol, trimethylene glycol, neopentyl glycol, hexamethylene glycol, and cyclohexane dimetatool. The polyether segment generally has a molecular weight of 400 to 1000, preferably 700 to 6,000.

More preferably, in the case of polytetramethylene glycol, it is 800 to 2000. The proportion of this polyether is 15 to BQ of the polyester/ether block copolymer.
wt, preferably 25 to 60 wt. Examples of polyethers include polytetramethylene glycol, polyethylene glycol, polypropylene glycol, copolymer glycol of ethylene oxide and propylene oxide, and copolymer glycol of ethylene oquinide and tetrahydrokerane. And poly 4A referred to in the present invention
Typical examples include polytetramethylene terephthalate and
Isophthalate polytetramethylene gel 1 nocolb a
polyethylene terephthalate/isophthalate/polytetramethylene glycol block copolymer (PET/I-PTM)
G), polytetramethylene terephthalate-isophthalate/polyethylene glycol block copolymer (
PBT/I-PFiG), polyethylene terephthalate/isophthalate/polyethylene glycol block copolymer CPET/I-PEG), and the like.

In the specification of the present invention, in order to clarify the components of Polymer A, they are divided into polyester segment portions and polyether segment portions and are expressed as follows.

For example, PBT/I-FTMO65735-so indicates that the copolymerization molar ratio of terephthalic acid/isophthalic acid consists of 50 wt segments of 65735 and 50 wt of ptMa.

The melting point of Polymer A must be 100°C or higher,
If the temperature is less than 100°C, it will take a long time to dry the polymer during melt extrusion, and heat resistance will be required when retorting containers made using a single adhesive film. Furthermore, the melting point of the polyester segment is t-12
The reason for limiting the temperature to 0 to 200 degrees is to obtain sufficient adhesive strength at as low a temperature as possible during thermal bonding. Adhesive strength is low when the temperature exceeds 200℃, the ratio of polymer A is 50 to 90wt
%, preferably 55 to 80 wt%, from the viewpoint of adhesive strength and retort resistance. When the content of Polymer A is less than 50 wt%, the adhesive strength after retort treatment is significantly reduced. On the other hand, 90w
If it exceeds t%, the heat resistance of the composition, especially in a high-temperature oxygen atmosphere, will be poor, and when one composition is made into a film, the film forming properties will be poor, edge formability, and thickness unevenness will be poor. Blocking becomes easier.

PolywB is a polyester in which terephthalic acid accounts for 60 moles or more (preferably 65 moles or more) of the total dicarboxylic acids, and contributes to film forming properties, film tightening properties, slip properties, etc. In particular, terefluoric acid of 70 to 65 mol is particularly preferred because it acts as an adhesion aid. Examples of dicarboxylic acids other than terephthalic acid include isophthalic acid and adipic acid.

Sepaconic acid, naphthalene dicarboxylic acid, dodecane dicarboxylic acid, etc. can be mentioned. Examples of diols include tetramethylene glycol, nitrogen glycol, trimethylene glycol, neopentyl glycol, hexamethylene glycol, and cyclohexane dimetatool.

Specific examples of polymer B include polytetramethylene tere-7 tally) (PR?), polytetramethylene terephthalate-iso7-talate copolymer (PBT/l), polytetramethylene, tele-7 tallate-sebacate copolymer ( P.B.
T/S), polyethylene terephthalate (PGLT), polyethylene terephthalate/inphthalate copolymer (P
BTE/I), polyethylene terephthalate spring 7-packate copolymer (PET/S), and the like. The proportion of terephthalic acid in all dicarboxylic acids is 6Qwt%
If the temperature is lower than that, the polymer must be dried at low temperature for a long time.

□The ratio of polymer B is 5 to 50 wt%, preferably 10 to 50 wt%.
At 25w1%, you can choose 2 or more types of 1111it. For example, when using PRTJ-ICPB
If used together with T/X-f, it will be better than FB'r alone.

Adhesive strength can be improved. In this case P B T/
I is particularly preferably 2Qwt% or less from the viewpoint of film tightening properties. If the content of Polymer B is less than 5 wt%, the film forming properties of the composition will be poor and it will be easy to tighten one roll. 3Q
If it exceeds wt%, the adhesive strength (particularly the adhesive strength after retort treatment) decreases significantly, which is not preferable.

Examples of polymer C include polypropylene (PP), copolymerized polypropylene with other α-olefins such as tyrene, polyethylene (PI), copolymers of ethylene and other α-olefins, and poly4-methylpentene. Acids, polymerizable unsaturated carboxylic acids such as acrylic acid, and their acid anhydrides and esters are preferably used in an amount of 0.1 to 3w.
Modified polypropylene copolymerized within the range of t% (modified p
p).

Examples of ε include modified polyethylene (modified pg) and the like. The melting point of these polymers C is 100°C or higher.

Particularly preferred is a temperature of 110° C. or higher in terms of drying and retort resistance of the composition. As Polymer C, ethylene/vinyl acetate copolymer cannot be used during melt extrusion of the composition or because of the acetic acid odor of the product due to its lack of thermal stability.
Furthermore, there is a drawback that the degree of improvement in heat sealability is small. Polymer C has a weight of 1 to 30 wt, preferably 2.5 to 30 wt.
It is 25wt%.

When the amount is less than 1 wt%, film forming properties and film slipperiness when extruding the composition into a film deteriorate.

Workability such as bag making becomes significantly worse. If it exceeds 30 wt%, the sea-island structure of the blend components is unstable or reversed, resulting in a decrease in adhesive strength.

It becomes a film that is easy to cut.

Specifically, the amount of polymer C is pp, modified pp.

Those with high melting points such as poly-4-methylpentene 1 -
15 wt% (preferably 2.5 to 10 wt%), PE.

8 to 30 wt% for relatively low melting point materials such as modified PI
(preferably 10 to 20 wt%) is used for adhesive strength,
Preferable in terms of lubricity.

Preferred specific examples of the composition of the present invention include the following.

(ll PBT/I-FTMO60~70-PB
'l'/I 10~20 tP
BT (t or PE/X) 10~20
zpp (or modified pp) 1-15w
t% total i QQwt% (2) PBT/I-PTMG 6
0-70wt%PBT/I
10-20 1PET (or PET/I)
10-20 1 Total 100wt% The composition of the present invention contains inorganic fine particles such as silicon chloride, calcium carbonate, Merck, kaolinite, sericite, magnesium oxide, zinc oxide, and alumina, oleic acid amide, erucic acid amide, and stearic acid. Organic lubricants such as amides, calcium stearate, stearyl alcohol,
Antioxidants such as hindered phenols and sulfur-containing antioxidants,
Various additives such as ultraviolet scavengers and pigments can be used as necessary.

It is particularly preferable that the composition of the present invention is used in the form of a film as an adhesive film, as well as a thermal adhesive layer of a thermally adhesive composite film, and a hot melt agent.

It is also used as a thermal adhesive for plastic films such as polyester and polyamide, and as it can withstand retort and boil sterilization, it is also used in various packaging materials.

It also has excellent adhesion to aluminum foil, iron plates, copper foil, etc., and exhibits excellent properties in fields such as wrinkled metal coating films. It is particularly effective as a sealant for retort pouches using aluminum foil.

Evaluation of physical properties in the present invention was performed by the following method.

(1) Film-forming property Edge formability when forming an unstretched film by melt extrusion and casting from a bimetallic metal.

Observe uneven thickness, etc. ◎: Excellent with no edge disturbance. ○: Good, Δ: Slightly poor. ×: A titrated film with disordered edges and large film width fluctuations was obtained, ◎ for less than 15 inches, and 0.25 inches or more for less than 1-25% of 15 inches or more
Less than % was rated as M, and 50% or more was rated as ×.

(2) Sealing property: The film is rolled in the longitudinal direction (
MD) Width 2 Em
Leave at 0°OX for 24 hours and measure the degree of shrinkage. In addition, a 100 m long roll was wound on a 5-inch paper tube, and the roll was left open for one week at 40°C, and the degree of winding was observed. x; The roll surface is uneven due to the unevenness of the film thickness and the winding appearance is poor.

(3) Masatsu coefficient: 2 test pieces with a width of 75 x 100
The film was left at 0° C. and 65% RH for 24 hours, and the back and front sides of the film were measured with a stacking load of 200 g. Displayed as static (masatsu)/dynamic (masatsu).

(4) Blocking = 2 films t-3X4c
2, and a load of 500 g was applied.

Measurement is performed after being left at 40°C and 84% RH for 24 hours.

In normal use, if it is less than 500g712cm,
'No problem.

(5) Heat seal crab Sandwich the film to be measured between unstretched PBT films with a thickness of 50μ.

190°0 with hot plate heat sealer. Seal with seal pressure 1/mouth and seal time 1 second. Then, after retorting the entire product, the elongation angle was 90° and the tensile speed was 200+mo/
The sealing force is constant at min.

(6) Heat sealer (part 2) Nialuminum base [20
μ)/Film/Overlaid on AI pattern paper structure, 240℃
The sealing force between aluminum foil and film was measured at a peel angle of 90 degrees.

(7) Retort treatment: After treatment at 120°C for 60 minutes, it is taken out and left to cool at room temperature.

Example 1 Polymer A: PBT/'I-PTMG (
65155-50), melting point 135°0. Polyester segment melting point 155°C, PTMG molecular weight 1000. L
v, 1.82 (determined in 0-chlorophenol at 25°C).

Boma B: P B'r, M point 220ri, I, V
, 0.92° Polymer C: low density polyethylene. M, L
4g/l 0mln.

The above polymers A, B, and C were mixed in the proportions shown in Table 1, and pelletized using a 250°C/40anφ extruder. After drying the chips at -130 °C.

It was supplied to a 40-φ extruder equipped with a nozzle having a width of 600 mm and an IJ hub gap of 0.8-mm, and melt extrusion was performed at 250°C. The mixture was cooled and solidified on a 500° cast drum to form a film with a thickness of 50 μm. As is clear from the results in Table 1, +a1 according to the present invention has good film forming properties, no double-wrap tightening, and good slipping properties, so it is extremely easy to handle as a film adhesive, and it can be used for sealing after retort processing. The force is also within the practical range.

On the other hand, conventional products H2 and 5 have poor film-forming properties and require a large amount of tightening per roll, and although they have sufficient heat sealability, they have poor slipperiness and blocking properties, making them impractical as film adhesives. The adhesion force of UG1 is also better than that of 凰2゜3.

Example 2 Polymer A: Pfl〒/I-P 'I' M O (70
150-70). Melting point: 155°C, polyester segment melting point: 170'o, ptMG molecular weight: 1 o Oo, r
, v, 102° Polymer B1: PET/Z (85
/15), melting point 222°C, 1. v, Q, 70° Polymer B! :PBte/I (65/35), melting point 155
℃.

r, v, i, o o.

Polymer C: polypropylene. [Mako 2.2 (measured at 155°C in tetralin), 1. ! , 97.8 regret.

The above polymer was pelletized in the same manner as in Example 1 in the proportions shown in Table 2, and an unstretched film with a thickness of 50p was wound up. There is no tightening, the film's lubricity and blocking are both good, and it is suitable for machining such as S bag work.

On the other hand, in the conventional product (ms, 6), the edges were easily disturbed and the film formation was unstable. The film roll is so tightly wound that it is difficult to unwind the film, and if you unwind it forcibly, the film will stretch.

The adhesive strength with aluminum foil is significantly superior to that of conventional products Ugami 5 and 6.

Example 3 Polymers A, B, and Cf used in Example 1: Table 3
An unstretched film (thickness: 30 μm) was prepared from the composition shown in Table 3.As shown in Table 3, if the content of Polymer A exceeds 90 wt%, the film formability and lubricity deteriorate, so it is not suitable for practical use as a film adhesive. Moreover, if it is less than 50wt or 4, film forming properties are good, but one roll tightening occurs and the sealing force decreases, which is not preferable.

A7 and 8.9 of the present invention have good film-forming properties and good lubricity, and the sealing force after retort treatment is not substantially changed.

Example 4 Polymer Aw: PBT7Z-pyMa (so7so-
25).

Melting point 115℃, polyester segment) melting point 150℃,
PTMG molecular weight 1000° polyv A2: PBT/I-PTMG (50150-
60n.

Melting point 98°C, PTMG molecular weight 2000° Polymer A8:
Polymer A used in Example 1.

Polymer B1: Polymer B of Example 1.

Polymer Bt: Polymer B2° of Example 2 Polymer C: Ethylene 5. Owt% copolymerized polypropylene/
. [Ma] 2.0° Also, for comparison, vinyl acetate content is 19w1%, M.

An unstretched film (thickness: 40 μm) having a composition shown in Table 1 was prepared using an ethylene/vinyl acetate copolymer (EVA) having a weight of 15 g and a weight of 710 min. Arashi 12.13 of the invention shows good film properties. On the other hand, WL15, which uses Polymer A2, which is unsuitable for Volima A, not only has slightly poor film forming properties, but also has extremely poor processability because the film does not slip.Although it has sufficient sealing power, it is difficult to soften the film during retort processing. The finish on the seal surface becomes ugly.

In case of -14, the amount of polymer B is 35 wt %, which causes a slight decrease in the strength and sealing force for one turn. Polymer C is 1 for Na16
Since it is less than wt%, the lubricity is extremely poor. Episode 17 is ET
Since A is used, there are deficiencies such as poor film forming properties, easy one-roll tightening, poor lubricity, and low sealing force.

Claims (1)

[Claims] (1) The melting point is 100°C or higher, and the melting point when the polymer is formed only from the polyester segment components is 12
50 to 90 wt% of a polyester ether block copolymer having a temperature of 0 to 200°C, 5 to 30 wt% of a polyester in which at least terephthalic acid accounts for 60 mol% or more of the total dicarboxylic acid component, and 1 to 30 wt% of a polyolefin.
A thermoadhesive composition consisting of.