JP2005097592A - Thermoplastic resin adhesive and reinforcing plate with thermoplastic resin adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin adhesive using an organic solvent imposing no environmental load, and capable of adhering in a short period of time at a low temperature similarly as conventional one. <P>SOLUTION: This thermoplastic resin adhesive is obtained by dissolving a non-crystalline thermoplastic resin and a lowly crystalline thermoplastic resin in an organic solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thermoplastic resin adhesive and a reinforcing plate with a thermoplastic resin adhesive.

  High crystalline polyester resin is softened by heat and pressure treatment at low temperature (80 ° C as a material temperature) and for a short time (1 second), and easily generates adhesive force. It is often used in.

  Usually, highly crystalline polyester resin is used as a thermoplastic resin adhesive by extrusion molding (a method in which a highly crystalline polyester resin is heated and melted at a high temperature in an extruder and then extruded and applied to an adherend). Is done. Since this method does not use a solvent, an error is likely to occur in the coating thickness. In particular, when the coating thickness is small, the error becomes a big problem.

  As another method using a solvent, there is a dissolution method (a method in which a highly crystalline polyester resin is dissolved in an organic solvent and applied to an adherend). In this case, a halogen-based organic solvent such as methylene chloride is often used as the organic solvent. However, the halogen-based organic solvent such as methylene chloride is not preferable because it gives a load to the environment. Development of a thermoplastic resin adhesive that exhibits adhesive strength at a low temperature and in a short time without using a resin is desired.

  Based on various experiments, the present invention provides a thermoplastic resin adhesive that can be bonded at a low temperature and in a short time as in the conventional products, using an organic solvent that does not affect the environment.

  The gist of the present invention will be described.

  The present invention relates to a thermoplastic resin adhesive characterized by dissolving an amorphous thermoplastic resin and a low crystalline thermoplastic resin in an organic solvent.

  The thermoplastic resin adhesive according to claim 1, wherein the organic solvent is an aromatic hydrocarbon such as toluene or xylene, or a single or a mixed solvent of two or more selected from ketones such as methyl ethyl ketone or dimethyl ketone. The present invention relates to a thermoplastic resin adhesive.

  The thermoplastic resin adhesive according to any one of claims 1 and 2, wherein the thermoplastic resin adhesive comprises an inorganic oxide.

  The thermoplastic resin adhesive according to claim 3 is a thermoplastic resin adhesive characterized in that talc is employed as the inorganic oxide.

  Further, in the thermoplastic resin adhesive according to any one of claims 1 to 4, a polyester resin having a glass transition temperature (Tg) of -40 to 7 ° C and a softening point of 60 to 130 ° C as an amorphous resin. The present invention relates to a thermoplastic resin adhesive characterized by adopting a polyester resin having a glass transition temperature (Tg) of -20 to 0 ° C. and a melting point of 70 to 120 ° C. as a low crystalline resin.

  The thermoplastic resin adhesive according to claim 5, wherein 40 to 70 parts by weight of the non-crystalline polyester resin and 60 to 30 parts by weight of the low-crystalline polyester resin are combined so that the total amount becomes 100 parts by weight. Thus, the present invention relates to a thermoplastic resin adhesive that is dissolved in an organic solvent.

  The thermoplastic resin adhesive according to claim 6, wherein 20 to 100 parts by weight of talc are dispersed with respect to 100 parts by weight of a mixture of an amorphous polyester resin and a low crystalline polyester resin. It relates to a resin adhesive.

  Moreover, it is a reinforcement board with a thermoplastic resin adhesive affixed on the flexible flat cable used as an internal wiring material of an electric / electronic device, Comprising: This reinforcement board is any one of Claims 1-7 to a synthetic resin film. The thermoplastic resin adhesive described in the item is applied and dried, and relates to a reinforcing plate with a thermoplastic resin adhesive.

  The reinforcing plate with a thermoplastic resin adhesive according to claim 8, wherein a polyethylene terephthalate or a polyimide film is used as the synthetic resin film.

  Since the present invention does not use a highly crystalline thermoplastic resin that requires a halogen-based organic solvent such as methylene chloride that imposes a burden on the environment, there is no harm to the environment.

  Moreover, since it is a method using a solvent (dissolution method), an error in the coating thickness hardly occurs.

  In addition, through experiments, the thermoplastic resin adhesive of the present invention exhibits the same adhesive force at a low temperature and in a short time compared to a thermoplastic resin adhesive using a conventional highly crystalline thermoplastic resin. Have confirmed.

  As described above, the present invention can use an organic solvent that does not give a load to the environment, and becomes a thermoplastic resin adhesive that can be bonded at a low temperature and in a short time as in the conventional product.

  In this example, a non-crystalline thermoplastic resin, a low crystalline thermoplastic resin and an inorganic oxide were dispersed in an organic solvent and dissolved in a polyethylene terephthalate or polyimide film. It is a reinforcing plate. This reinforcing plate is attached to both end faces of the flexible flat cable.

  The flexible flat cable is formed by arranging conductive wires in parallel and sandwiching them together with two insulating resin films with an adhesive, and is mainly used as an internal wiring material for electrical and electronic equipment materials. in use.

  The non-crystalline thermoplastic resin has no melting point and cannot be in a crystallized state, or has a very low crystallinity even when crystallized, and has a glass transition temperature (hereinafter referred to as Tg) of −40 to 7 The one in the range of ℃ is adopted.

  The low crystalline thermoplastic resin has a melting point and is in a crystallized state but has a relatively low crystallinity and a Tg in the range of -20 to 0 ° C. This low crystalline thermoplastic resin is soluble in halogen-based organic solvents and general-purpose organic solvents such as toluene.

  A highly crystalline thermoplastic resin having a Tg of −60 ° C. or lower is not used. This is because, as a result of the experiment, a highly crystalline thermoplastic resin having a Tg of −60 ° C. or lower is soluble only in a nonpolar halogen-based organic solvent such as methylene chloride. However, as described above, halogen-based organic solvents such as methylene chloride are not suitable for giving a load to the environment.

  Also, a crystalline thermoplastic resin having a Tg of 1 ° C. or higher is not employed. This is because, as a result of experiments, crystalline thermoplastic resins with a Tg of 1 ° C. or higher can be dissolved in non-halogen solvents, but they cannot meet the required characteristics due to difficulty in bonding or pressure bonding by heating for a short time. It is.

  The softening point of the amorphous thermoplastic resin is in the range of 60 to 130 ° C. Within the range of the softening point, the amorphous thermoplastic resin is easily softened. That is, the plasticity is easily developed by heating at a low temperature (80 ° C. as the material temperature) which is a required condition.

  As a result of the experiment, if the softening point is 60 ° C. or less, for example, plasticity is easily expressed under a temperature condition close to room temperature, which is not preferable for practical use. It has been found that it does not soften at the time of thermocompression bonding and cannot satisfy the required characteristics.

  The melting point of the low crystalline thermoplastic resin is in the range of 70 to 120 ° C. Within the range of the melting point, as in the case of the non-crystalline thermoplastic resin, plasticity is easily developed by heating at a low temperature (80 ° C. as a material temperature) which is a required condition.

  In addition, as a result of the experiment, if the melting point is 70 ° C. or less, for example, plasticity is easily expressed under temperature conditions close to room temperature. It has been found that it does not soften during the thermocompression bonding and cannot satisfy the required characteristics.

  The non-crystalline thermoplastic resin and the low-crystalline thermoplastic resin are not employed alone.

  This is because the non-crystalline thermoplastic resin cannot be in a crystallized state, and when used alone, the viscosity is too strong, and when used as a reinforcing plate described later, the surface of the adhesive layer of the reinforcing plate This is because the sticking phenomenon causes very strong blocking phenomenon in which stacked or rolled reinforcing plates adhere to each other, making it very difficult to put into practical use.

  Incidentally, when an inorganic oxide is added to the non-crystalline thermoplastic resin, the blocking property can be improved to some extent, but the required adhesive strength is not exhibited by adhesion by short-time heating or thermocompression bonding.

  In addition, since the low crystalline thermoplastic resin is a resin having a relatively high melting point, when used alone, when used as a reinforcing plate described later, it is difficult to melt at a low temperature for a short time, This is because the required adhesive strength cannot be realized.

  From the above, it is difficult to satisfy both of the non-crystalline thermoplastic resin and the low crystalline thermoplastic resin alone, so that both are used in combination. When both are combined in this way, problems such as blocking being too strong and difficulty in melting are solved.

  The non-crystalline and low-crystalline thermoplastic resins are dissolved in an organic solvent other than a halogen-based organic solvent such as methylene chloride to form a thermoplastic resin adhesive.

  The organic solvent employs an aromatic hydrocarbon such as toluene or xylene, or a single or a mixed solvent of two or more selected from ketones such as methyl ethyl ketone or dimethyl ketone.

  Specifically, 40 to 70 parts by weight of the non-crystalline thermoplastic resin and 60 to 30 parts by weight of the low crystalline thermoplastic resin are blended so that both are 100 parts by weight, It is dissolved in a mixed solvent of toluene and methyl ethyl ketone.

  As a result of the experiment, when the amount of the amorphous thermoplastic resin is 40 parts by weight or less, the thermoplastic resin adhesive becomes too hard and is not suitable. When the amount is 70 parts by weight or more, the viscosity of the thermoplastic resin adhesive is not suitable. Has been found to be excessive and unsuitable.

  Similarly, as a result of the experiment, if the low crystalline thermoplastic resin is 30 parts by weight or less, the viscosity of the thermoplastic resin adhesive becomes excessive and is not suitable, and if it is 60 parts by weight or more, the thermoplastic resin adhesive Has become too hard to be suitable.

  Further, as a result of the experiment, it has been confirmed that the thermoplastic resin adhesive obtained by the above means exhibits the required adhesive force by low-temperature and short-time heat bonding or pressure bonding.

  More specifically, it has been confirmed that the thermoplastic resin adhesive of this example can be bonded if the temperature of the thermoplastic resin adhesive is in the range of 80 ° C to 120 ° C.

  When the temperature of the thermoplastic resin adhesive is 80 ° C. or lower, a desired adhesive force cannot be obtained, and when it is 120 ° C. or higher, the synthetic resin film is deformed (eg curled) by heat. Have confirmed.

  The thermoplastic resin adhesive is applied to a synthetic resin film and dried to form a reinforcing plate with a thermoplastic resin adhesive.

  The synthetic resin film employs polyethylene terephthalate or polyimide film.

  As described above, the reinforcing plate with the thermoplastic resin adhesive is reinforced with the thermoplastic resin adhesive when the thermoplastic resin adhesive after drying produces a sticky return and is stacked or rolled. There may be a blocking phenomenon in which the plates adhere to each other. Therefore, for the purpose of preventing this blocking, by adding an inorganic oxide adopted from aluminum hydroxide, silica gel, talc, etc. to the non-crystalline and low-crystalline thermoplastic resins, The reinforcing plate with the thermoplastic resin adhesive is imparted with blocking resistance.

  Specifically, 40 to 70 parts by weight of the non-crystalline thermoplastic resin and 60 to 30 parts by weight of the low-crystalline thermoplastic resin are combined so that the total amount becomes 100 parts by weight. 20 to 100 parts by weight of talc is added to 100 parts by weight and dissolved or dispersed in the above-described mixed solvent of toluene and methyl ethyl ketone.

  In this case, the amount of the mixed solvent of toluene and methyl ethyl ketone can be appropriately adjusted in order to obtain a desired resin thickness (coating thickness).

  As a result of experiments, if the amount of talc added is 20 parts by weight or less, the effect of improving blocking cannot be exhibited, and if it is 100 parts by weight or more, a predetermined adhesive force cannot be realized. And a reinforcing plate with a thermoplastic resin adhesive having blocking resistance while maintaining a strong adhesive force.

  The aluminum hydroxide and the silica gel are not adopted because the peel strength is not satisfied as a result of the experiment.

  The thermoplastic resin adhesive is preferably applied to the synthetic resin film at a coating thickness of 5 to 50 μm. This is because if the thickness is less than 5 μm, the predetermined adhesive force cannot be expressed, and if it is 51 μm or more, the leveling property (coating property) deteriorates. More preferably, it is 20-50 micrometers.

  In addition, the thickness of the synthetic resin film is preferably 50 μm or more in the reinforcing plate with the thermoplastic resin adhesive as in this example, for example, where the film itself needs a certain degree of strength (roughness), More preferably, it is 100 micrometers or more.

  The present embodiment is excellent in blocking resistance even after being stored in a roll at room temperature for a long time by the means described above, and can be bonded by low temperature and short time heating or can be heat and pressure bonded at low temperature and short time. became.

  This reinforcing plate with a thermoplastic resin adhesive can be used, for example, for reinforcing both end faces of a flexible flat cable made of polyethylene terephthalate or polyimide film.

  As described above, this embodiment uses an organic solvent that does not give a load to the environment, and can be bonded at a low temperature and in a short time as in the conventional product, and becomes a reinforcing plate with a thermoplastic resin adhesive having blocking resistance.

  Next, the characteristics of this example will be described with reference to a conventional example (comparative example). In addition, each performance of a prior art example and a present Example compared by the method described about the following items.

(1) Properties as a thermoplastic resin adhesive Tensile strength (MPa), Young's modulus (MPa), elongation (%), and Tg (° C) were measured according to JIS definitions.

(2) Properties as a reinforcing plate with a thermoplastic resin adhesive Thickness (μm), blocking resistance, and peel strength were measured.

  The anti-blocking property was measured by stacking two adhesive-attached films in the same direction, applying a load of 0.3 MPa in an atmosphere of 50 ° C., leaving it for 7 days, and measuring the peel strength in accordance with JIS K 6854. The smaller the peel strength, the better the blocking resistance.

  The peel strength was measured by hot pressing (pressure 0.3 MPa, press temperature 130 ° C.) for 1 second so that the temperature of each of the film with adhesive and the polyethylene film was 80 ° C., and the atmosphere was determined according to JIS K 6854. Peel strength (at temperatures of -20, 0, 20, 40, 60, and 80 ° C) and post-treatment room temperature peel strength (70 ° C x 7 days, 120 ° C x 7 days, 150 ° C x 7 days, 40 ° C X 95% RH x 4 days later, 85 ° C x 85% RH x 4 days later, methanol immersion x 10 minutes later).

<Conventional example>
As a crystalline thermoplastic resin, a mixed solvent of 100 parts by weight of Byron GM-920 (molecular weight 30000, Tg-60 ° C., melting point 108 ° C.) manufactured by Toyobo Co., Ltd., 56 parts by weight of toluene and 320 parts by weight of methylene chloride. A suspension was prepared by dissolving and dispersing to obtain a thermoplastic resin adhesive. The obtained thermoplastic resin adhesive was applied to a polyethylene film and dried. Table 1 shows the characteristics of this thermoplastic resin adhesive and the film with the thermoplastic resin adhesive obtained by applying and drying this thermoplastic resin adhesive on a polyethylene film.

<Example>
As an amorphous thermoplastic resin, 54 parts by weight of Unitika's Elitele UE-3410 (molecular weight 30000 or more, Tg-29 ° C., softening point 70 ° C.), and as a low crystalline thermoplastic resin, 46 parts by weight Byron SF-237 (molecular weight 30000, Tg-4 ° C., melting point 110 ° C.) manufactured by Toyobo Co., Ltd., and 50 parts by weight of P-2 manufactured by Nippon Talc Co., Ltd. as talc, 253.4 parts by weight of toluene and 130.6 A suspension was prepared by dissolving and dispersing in a mixed solvent of methyl ethyl ketone in parts by weight to obtain a thermoplastic resin adhesive. The obtained thermoplastic resin adhesive was applied to a polyethylene film and dried. As shown in Table 1, the properties of this thermoplastic resin adhesive and a film with a thermoplastic resin adhesive obtained by applying and drying this thermoplastic resin adhesive on a polyethylene film are comparable to the conventional examples. Met.

Claims (9)

  A thermoplastic resin adhesive comprising an amorphous thermoplastic resin and a low crystalline thermoplastic resin dissolved in an organic solvent.   2. The thermoplastic resin adhesive according to claim 1, wherein an organic solvent is an aromatic hydrocarbon such as toluene or xylene, or a single or a mixed solvent of two or more selected from ketones such as methyl ethyl ketone or dimethyl ketone. A thermoplastic resin adhesive characterized by   The thermoplastic resin adhesive according to any one of claims 1 and 2, wherein an inorganic oxide is blended.   4. The thermoplastic resin adhesive according to claim 3, wherein talc is employed as the inorganic oxide.   The thermoplastic resin adhesive according to any one of claims 1 to 4, wherein a polyester resin having a glass transition temperature (Tg) of -40 to 7 ° C and a softening point of 60 to 130 ° C is used as the amorphous resin. A thermoplastic resin adhesive comprising a polyester resin having a glass transition temperature (Tg) of -20 to 0 ° C and a melting point of 70 to 120 ° C as a low crystalline resin.   The thermoplastic resin adhesive according to claim 5, wherein 40 to 70 parts by weight of the non-crystalline polyester resin and 60 to 30 parts by weight of the low crystalline polyester resin are combined so as to be 100 parts by weight. A thermoplastic resin adhesive which is dissolved in an organic solvent.   The thermoplastic resin adhesive according to claim 6, wherein 20 to 100 parts by weight of talc is dispersed with respect to 100 parts by weight of a mixture of an amorphous polyester resin and a low crystalline polyester resin. Agent.   It is a reinforcement board with a thermoplastic resin adhesive affixed on the flexible flat cable used as an internal wiring material of an electrical / electronic apparatus, Comprising: This reinforcement board is a synthetic resin film in any one of Claims 1-7. A thermoplastic resin adhesive-attached reinforcing plate, wherein the thermoplastic resin adhesive according to the description is applied and dried. 9. The reinforcing plate with a thermoplastic resin adhesive according to claim 8, wherein a polyethylene terephthalate or a polyimide film is used as the synthetic resin film.