JPH06145632A - Polyester hot melt resin composition for inflation molding - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of being readily formed into a film, excellent in adhesivity and blocking resistance, and suitable for hot-melt tubes, etc., by adding a saturated fatty acid monoamide and a crystallization nuclear agent in prescribed amounts, respectively, to a specific polyester based hot-melt resin. CONSTITUTION:The objective composition comprises (A) a polyester based hot-melt resin and (B) 0.1-3wt.%. of a saturated fatty acid monoamide such as behenic acid amide as a processing auxiliary and (C) 0.2-3wt.%. of one kind or more of crystallization nuclear agents such as tale, clay, magnesium stearate, and calcium stearate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester hot melt resin composition which can be easily formed into a film by an inflation method and has excellent adhesiveness to metals, glass, plastics, wood and the like.

[0002]

2. Description of the Related Art In recent years, hot melt adhesive resins have been
It is widely used in various industrial fields including production sites of electric parts and automobile parts because it has less environmental pollution problems and is extremely advantageous in improving productivity as compared with solution type adhesives.

By the way, as the hot-melt adhesive resin, resins such as polyolefin-based, polyurethane-based, polyamide-based, and polyester-based resins have been generally well known, but especially polyester-based hot-melt adhesive resins are In addition to excellent heat resistance, it has many unique properties in terms of cold resistance, adhesiveness, chemical resistance, and odorlessness, so its application fields are expanding.

On the other hand, in order to further facilitate the handling of such hot-melt resin, there has recently been found that the hot-melt resin is processed into a film or sheet shape. Have already put into practical use a sheet obtained by extrusion-coating the surface of a release support such as paper or film with the resin.

Among these, polyester hot melt resins are usually prepared by copolymerizing terephthalic acid as an acid component with isophthalic acid, adipic acid, succinic acid, glutaric acid, or ethylene glycol as an alcohol component. The adhesive function is improved by copolymerizing 1,3-propanediol, 1,4-butanediol, neopentyl glycol and the like (see, for example, JP-A-57-12080 and JP-A-55-55). No. 43118, etc.), low-melting polyester-based hot-melt resins have good adhesiveness, but on the other hand, they have a low crystallization rate and thus easily block after extrusion molding. The only way to make a film is by extrusion coating on the surface of the release support, let alone a polyester system of this kind. The inflation molding at Ttomeruto resin alone, it is fact is has been considered hardly possible before.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the blocking phenomenon after extrusion molding without impairing the properties peculiar to hot-melt resins. It is an object to provide a polyester hot melt resin composition which can be easily formed into a film by an inflation method even by itself, and which has excellent adhesiveness, particularly peel adhesion strength.

[0007]

Means for Solving the Problems The inventors of the present invention have diligently studied anti-blocking measures for polyester-based hot-melt resins in order to achieve such an object. Unexpectedly, if a saturated polyamide monoamide and a crystallization nucleating agent are used in combination with a low melting point type polyester hot-melt resin, which has been difficult to achieve compatibility, the original adhesiveness of the resin is impaired. It was found that the blocking phenomenon and the inflation moldability were significantly improved without the need to complete the present invention.

That is, in the present invention, 0.1 to 3% by weight of saturated fatty acid monoamide as a processing aid and 0.2 to 3% by weight of a crystallization nucleating agent are added to a polyester hot melt resin having a melting point of 80 to 120 ° C. The present invention relates to a polyester hot melt resin composition for inflation molding characterized by being blended with each other.

Hereinafter, the polyester hot melt resin composition for inflation molding of the present invention will be described in detail.

The composition of the present invention has a melting point of 80 to 120 ° C.
It is based on the above polyester hot melt resin.

Here, the polyester hot melt resin means various saturated copolyesters such as terephthalic acid, isophthalic acid, phthalic acid, adipic acid, sebacic acid, succinic acid, glutaric acid, pimelic acid as acid components.
Suberic acid, azelaic acid, p-oxybenzoic acid, nonanedicarboxylic acid, dodecanedicarboxylic acid, trimellitic acid, and the like, and at least two or more kinds, and ethylene glycol, diethylene glycol, 1,3 as a glycol component.
-Propanediol, 1,4-butanediol, 1,6
-Hexanediol, neopentylglycol, polyethyleneglycol, polytetramethyleneglycol, cyclohexanedimethanol, trimethylolethane, pentaerythritol, etc. are used and the polyesters obtained by copolymerizing these in various combinations are mentioned. The copolymerized polyester may be further mixed with styrene resin, phenol resin, epoxy resin, or the like.

The method of polymerizing these copolyesters is not particularly limited, but usually, the acid component or the ester forming derivative thereof is directly esterified or transesterified with the glycol component simultaneously or stepwise. In general, any of various catalysts, tackifiers, viscosity modifiers, stabilizers, fillers, etc. may be used at this time, and coloring agents, conductivity-imparting agents, etc. may be added if necessary. Absent.

The polyester hot melt resin used in the present invention is one having a low melting point of 80 to 120 ° C., preferably 90 to 115 ° C., among the above-mentioned copolyesters.

That is, the composition of the present invention must basically be a polyester resin having an appropriate degree of crystallinity so that it can be formed into a film by inflation molding in addition to excellent adhesiveness. The melting point of the polyester hot melt resin is lower than the value of the present invention when the melting point of the polyester hot melt resin is lower than the value of the present invention.
Not only is it difficult to form a stable film, but also the adhesiveness between the raw materials becomes so strong that even the supply of raw materials cannot be satisfied. On the other hand, when the melting point of the polyester-based hot melt resin is higher than the value of the present invention, it is difficult to obtain sufficient adhesive strength because flexibility tends to decrease even if flexibility decreases, and the film devitrifies during inflation molding. The problem arises that it becomes easier. The polyester hot melt resin used in the present invention is required to satisfy the above melting point, but in order to carry out inflation molding more stably, the melt viscosity at 200 ° C. is 200 to 2000 poise. Is preferred.

Further, the hot-melt resin composition for inflation molding of the present invention contains 0.1 to 3% by weight, preferably 0.3 to 2% by weight, of saturated fatty acid monoamide as a processing aid in the copolymerized polyester resin. And 0.2 to 3% by weight of a crystallization nucleating agent, preferably 0.5 to 2
It is the one in which each weight% is mixed.

In the present invention, the effect that can be obtained by blending the saturated fatty acid monoamide is mainly to improve the openability of the tube during inflation molding without deteriorating the excellent adhesiveness inherent in the hot melt resin. is there.

Examples of the saturated fatty acid monoamide include at least one of lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. If it is less than%, the effect of improving the tube opening property is poor and it becomes difficult to carry out inflation molding. On the other hand, if it exceeds 3% by weight, the saturated fatty acid monoamide bleeds out and hinders the adhesion of the hot melt resin. In addition, fluctuations in extrusion occur, making stable inflation molding impossible. In the present invention, behenic acid amide is particularly preferably used among the saturated fatty acid monoamides in terms of adhesiveness and openability.

Further, the crystallization nucleating agent blended with the saturated fatty acid monoamide in the composition of the present invention promotes crystallization of the low melting point polyester hot melt resin described above and is excellent in stabilizing the inflation moldability. It is effective, and it is presumed that it is based on the following reasons.

That is, while the molten tube extruded from the extruder is cooled by an air ring and is guided to the nip roll, compressed air is blown to expand the tube.
In the so-called inflation molding method, when the film tension (σ) in the molding process is (p) the gas pressure inside the bubble, (t) the film thickness, and (r) the bubble radius, σ =
Since the film tension constantly changes during molding as indicated by the relationship rp / t, the quality of the moldability depends largely on the crystallinity of the film. For example, in the case of a film having crystallinity such as ordinary polyethylene terephthalate, Even if the film tension increases, the film strength is also increased by crystallization at the same time, so that the two are easily balanced, and therefore, the molding can be performed while maintaining a relatively stable shape.

On the other hand, in the low melting point polyester hot melt resin as in the present invention, the film strength cannot follow the increase of the film tension during molding because of its low crystallinity, and as a result, bubbles are generated. If there is a puncture, or if a part of the bubble becomes even thinner than the other part, that part will continue to expand preferentially and the bubble will become distorted, and very stable molding cannot be done,
Therefore, the crystallization nucleating agent in the present invention has an excellent effect of improving the unstable moldability found in such a low crystalline polyester hot melt resin and enabling smooth molding.

In the present invention, the crystallization nucleating agent may be basically any as long as it promotes crystallization of the polyester hot melt resin, but normally, talc,
Natural mineral substances such as clay, kaolin, mica, bentonite, graphite, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, aluminum sulfate, calcium sulfate, magnesium sulfate, calcium stearate, magnesium stearate, titanium oxide, aluminum oxide, etc. At least one of
Among them, talc, clay, calcium stearate, and magnesium stearate are preferable because they act particularly effectively for improving the inflation moldability.

In the composition of the present invention, the amount of the crystallization nucleating agent is 0.2 to 3% by weight. When the amount is less than 0.2% by weight, the crystallization promoting effect is small. While improvement in inflation moldability cannot be expected so much, when the compounding amount of the crystallization nucleating agent exceeds 3% by weight, not only the adhesive strength is lowered, but also fish eyes frequently occur, and the so-called "eye stain" is often used during inflation molding. The deposit referred to as "" adheres to the die lip and causes a problem in continuous formability. The above crystallization nucleating agent has a particle size of 30 μm or less, especially 1
It is preferably 0 μ or less, and when the particle size is larger than 30 μ, the surface condition of the film is deteriorated and the fluctuation at the time of extrusion becomes large.

Hereinafter, the polyester hot melt resin composition for inflation molding of the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

The methods of measuring and evaluating the physical properties used in the present invention are as follows. (1) Adhesive strength (unit: kg / 25 mm) After sandwiching a hot-melt resin film (thickness 40 μ) between 25 μm-thick polyester films, the temperature of the heating plate is set to about 30 from the melting point of the test hot-melt resin. Two polyester films were bonded under the condition of a pressure of 1 kg / cm @ 2 while maintaining a high temperature of .degree. Next, a 180-degree peeling test was performed on the two polyester films under the conditions of an atmospheric temperature of 23 ° C. and a pulling speed of 200 mm / min to evaluate the adhesive strength. (2) Inflation moldability In film formation by the inflation method, there were few extrusion fluctuations and bubble fluctuations, and films that could be stably formed were defined as (good), and those that were difficult to form were defined as (defective). However, as for this (defective), the cause is mainly due to the violent fluctuation of the bubble (defective-A), mainly due to the poor opening property of the tube due to blocking (defective-B), mainly due to extrusion fluctuation and visual Those having poor stability due to the generation of tars and the like were represented as (defective-C).

Examples 1 to 4, Comparative Examples 1 and 2 Using a twin-screw kneading extruder, behenic acid amide was added to a polyester hot melt resin having a melting point of 90 ° C. (“HARDEC A6300” manufactured by Asahi Kasei Kogyo Co., Ltd.). 8% by weight, and 0.1% of talc (particle size 1.8 μ) as a crystallization nucleating agent,
Kneading was carried out at a compounding ratio of 0.3, 1.0, 1.5, 2.5, 4.0% by weight to prepare a test raw material. Continued,
The obtained raw material is supplied to a 50φ extruder and the resin temperature is set to 130
After extruding into a tube shape at 0 ° C., inflation molding was performed with a blow ratio of 2.1 while air cooling with an air ring. Table 1 shows the evaluation results of the inflation moldability in this test and the adhesive strength of the obtained hot melt film (thickness 40 μm).

[0026]

[Table 1]

Examples 5 to 7, Comparative Examples 3 to 4 Behenic acid amide compounding ratios of 0, 0.2, 1.0,
The same test as in Example 2 was conducted except that the content was changed to 2.5 and 4.0% by weight. The results are shown in Table 2.

Comparative Example 5 The same method as in Example 1 except that a polyester hot melt resin having a melting point of 128 ° C. (“HARDEC A3200” manufactured by Asahi Kasei Corporation) was used and the resin temperature during extrusion was 160 ° C. The test was conducted at. The results are shown in Table 2.

[0029]

[Table 2]

Comparative Example 6 The same test as in Example 2 was carried out except that erucic acid amide (melting point: 82 ° C.), which is a kind of unsaturated fatty acid monoamide, was used instead of behenic acid amide. As a result, the adhesive strength was relatively good at 3.2 kg / 25 mm, but the openability of the tube after inflation molding was extremely poor, and film formation was difficult.

From the results of Tables 1 and 2 and Comparative Example 6 above,
The polyester hot melt resin composition of the present invention can be easily formed into a film by the inflation method, and the obtained film has excellent adhesiveness.

[0032]

As described above, the composition of the present invention has a low melting point polyester hot melt resin in which a saturated fatty acid monoamide and a crystallization nucleating agent are mixed in specific amounts, respectively, to obtain excellent adhesiveness inherent to the resin. Without interfering with the effects of improving the blocking resistance of saturated fatty acid monoamide and the moderate crystallization promoting effect of the crystallization nucleating agent, it has been impossible to achieve this by using this type of hot melt resin alone. It was possible to achieve the remarkable effect that film formation by the method can be easily performed. Further, the composition of the present invention is not limited to the application as a hot melt film, and is advantageous in that it can be formed into a tube peculiar to the inflation method. It has a wide range of applications such as being particularly suitable as a tube.

Claims (3)

[Claims] 1. A polyester hot melt resin having a melting point of 80 to 120 ° C., 0.1 to 3% by weight of a saturated fatty acid monoamide as a processing aid, and 0.2 to a crystallization nucleating agent.
A polyester hot melt resin composition for inflation molding, characterized in that the composition is blended in an amount of 3 to 3% by weight. 2. The polyester hot melt resin composition for inflation molding according to claim 1, wherein the saturated fatty acid monoamide is behenic acid amide. 3. The polyester hot melt resin composition for inflation molding according to claim 1, wherein the crystallization nucleating agent is at least one of talc, clay, magnesium stearate and calcium stearate.