JPH06145631A - Hot-melt resin composition for inflation molding - Google Patents

Abstract

PURPOSE:To provide 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 prescribed amount of a saturated fatty acid monoamide to a specific polyester based 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.

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 formed into a film or a sheet and processed. 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.), among these polyester-based hot melt resins, those having a low melting point have good adhesiveness, but on the other hand, they have a low crystallization rate and therefore easily block after extrusion molding.
Therefore, at present, the only method for forming a film is to perform extrusion coating on the surface of the release support by the T-die method, let alone inflation molding using this type of polyester hot melt resin alone. It is the actual situation.

[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 made earnest studies on blocking countermeasures for polyester hot melt resins in order to achieve such an object. Surprisingly, if a certain amount of saturated fatty acid monoamide is blended into the low melting point type polyester hot melt resin, which has been difficult to achieve both at the same time, the blocking phenomenon will be greatly reduced without impairing the original adhesiveness of the resin. The inventors have found that they are improved and have completed the present invention.

That is, according to the present invention, a hot-melt resin composition for inflation molding is characterized in that 0.1 to 3% by weight of a saturated fatty acid amide is added as a processing aid to a polyester hot-melt resin having a melting point of 90 to 120 ° C. It relates to things.

The hot-melt resin composition for inflation molding of the present invention will be described in detail below.

The composition of the present invention has a melting point of 90 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, neopentyl glycol, polyethylene glycol, polytetramethylene glycol, cyclohexanedimethanol, trimethylolethane, pentaerythritol and the like are used, and a polyester obtained by copolymerizing these in various combinations is used. 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 has a low melting point of 90 to 120 ° C., preferably 95 to 115 ° C., among the above 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-based hot melt resin used in the present invention is required to satisfy the above melting point. However, in order to perform inflation molding more stably, it is preferable that the melt viscosity at 200 ° C. is 300 to 2000 poises. preferable.

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. It was done.

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.

Here, as the saturated fatty acid monoamide, at least one kind of lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, etc. is exemplified, and its blending amount is 0.1% by weight. 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.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The methods for 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, the reason for this (defective) is that it is mainly due to the violent rocking of the bubble (defective-A), mainly due to the poor opening of the tube due to blocking (defective-B), and is mainly stable due to extrusion fluctuation. Those having poor sex were represented as (Poor-C).

Examples 1 to 4 and Comparative Examples 1 and 2 Using a biaxial kneading extruder, behenic acid as a saturated fatty acid monoamide was added to a polyester hot melt resin (Made by Asahi Kasei Kogyo Co., Ltd. "HARDEC A5410") having a melting point of 106 ° C. Amide (melting point 100 ℃) 0, 0.2, 0.5,
Kneading was performed at a compounding ratio of 1.0, 2.5, and 4.0% by weight to prepare a test material. Continue to add 5
After being supplied to a 0φ extruder and extruded into a tube shape at a resin temperature of 140 ° 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).

[0021]

[Table 1]

Examples 5 to 6 and Comparative Examples 3 to 4 Polyester hot-melt resins having melting points of 80, 90, 114, and 128 ° C. (all of which are "HARDEC" manufactured by Asahi Kasei Kogyo Co., Ltd.) were used, and the resins were extruded. 30 to 40 depending on the melting point of the hot melt resin used.
The test was conducted in the same manner as in Example 3 except that the temperature was raised by 0 ° C. The results are shown in Table 2.

Comparative Example 5 The same test as in Example 3 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. The results are shown in Table 2.

[0024]

[Table 2]

From the results shown in Tables 1 and 2 above, the 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.

[0026]

As described above, the composition of the present invention comprises a polyester-based hot melt resin having a low melting point and a saturated fatty acid monoamide in a specific amount to prevent blocking of the excellent adhesiveness of the resin. It has improved properties, and it has the remarkable effect that it can be easily formed into a film by an inflation molding method, which has been impossible with the conventional hot melt resin alone. 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 (2)

[Claims] 1. A hot melt resin composition for inflation molding, comprising a polyester hot melt resin having a melting point of 90 to 120 ° C. and 0.1 to 3% by weight of a saturated fatty acid monoamide as a processing aid. 2. The hot melt resin composition for inflation molding according to claim 1, wherein the saturated fatty acid monoamide is behenic acid amide.