JPH0513169B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a thermoplastic resin molded product mainly composed of a thermoplastic polymer having a polar group in its side chain, which has improved adhesive properties. [Prior art] Conventionally, in thermoplastic resin molded products mainly made of thermoplastic polymers having polar groups as side chains, in order to improve the adhesiveness of the resin molded products, it has been proposed to increase the number of side chains with polar groups. methods have been commonly used. However, with this method, the thermal stability of the resin rapidly deteriorates, and in severe cases, the polymer decomposes, making melt extrusion impossible. It has drawbacks such as being able to be blended only with polymers that can be extruded at low temperatures, that is, polymers with poor heat resistance, or being unable to be extruded at high temperatures, making it impossible to obtain sufficient adhesive strength during extrusion lamination and requiring re-adhesion. [Objective of the Invention] The object of the present invention is to create a material that does not have the above disadvantages, that is, has excellent adhesive properties without sacrificing thermal stability, by unevenly distributing polar groups present as side chains on the surface layer. It is an object of the present invention to provide a thermoplastic resin molded product mainly composed of a thermoplastic polymer having a polar group as a side chain. [Structure of the Invention] The present invention provides a thermoplastic resin molded product mainly composed of a thermoplastic polymer having a polar group as a side chain, in which the polarity index at the surface layer of the molded product is 1.5% greater than the polarity index at the center in the thickness direction. It is characterized by a thermoplastic resin molded product that is larger than the above. In the present invention, a thermoplastic polymer having a polar group as a side chain refers to a thermoplastic polymer having a polar group having the following structure in a side chain.

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[Formula] -cl In the formula, R ₁ , R ₂ and R ₃ each represent hydrogen or an aliphatic hydrocarbon residue having 1 to 10 carbon atoms. In the formula, Me refers to an alkali metal or an alkaline earth metal. The number of polar groups contained in one branch chain is not particularly limited, but is preferably 1 to 100, more preferably 1 to 10. Furthermore, it is not necessary that all the side chains have polar groups as shown above, and some nonpolar groups may be present in the side chains. The polar groups present in the side chains include -COOH,

〔Effect of the invention〕

The present invention makes it possible to greatly improve the adhesiveness of the resin composition by concentrating the polar groups present as side chains on the surface layer. [Method of Measuring Properties and Criteria for Evaluation] The methods for measuring properties and the criteria for evaluation in the present invention are as follows. (1) Adhesive strength: A sheet-like object (film) to be measured with a thickness of 15 μm is sandwiched between an Al foil coated with a urethane resin anchor and the base material whose adhesive strength is to be evaluated, and the adhesive strength is set at a predetermined adhesion temperature and a surface pressure of 1 kg. / ^cm2 = 1
Hot glue for seconds. The sample thus obtained was cut into strips with a width of 1 cm, and peeled using Tensilon manufactured by Toyo Baldwin at a peel angle of 180°C and a peel speed of 20 mm/min.The average peel strength at that time was determined as the adhesive strength. And so. (2) Kyokusei index: Using ESCA (photoelectron spectrometer) model 750 manufactured by Shimadzu Corporation, M _g −K _a
Measured using a line. The concentration of polar groups on the surface of the film or at the center in the thickness direction for evaluating the adhesive strength with the base material was expressed as a relative integrated strength (%) with respect to C _1S , and this was taken as the polarity index. For example, when the polar group is an epoxy group or a carboxyl group, the relative integrated intensity (O _1S /C _1S ) was calculated from the peak areas of O _1S and C _1S and used as the polarity index. [Example] Hereinafter, embodiments of the present invention will be described based on Examples. Examples 1-3, Comparative Examples 1-2 Dow Chemical Company EAA [ethylene/acrylic acid copolymer, acrylic acid 8%, MI=9.0 (ASTM
D1238), Vikatsu softening point = 82℃ (ASTM
D1525), tensile strength = 180Kg/cm ² (ASTM D638)]
at 240℃ using an extruder with a diameter of 40 mm and L/D 22.
It is melted and discharged from a 400 mm wide nozzle onto a casting drum with a surface temperature of 70°C to form a 15 μm thick film. However, the casting drum,
The extruder and die shall all be grounded. At this time, the film discharged from the nozzle is
Place a wire electrode on the contact point that contacts the casting drum, and extend 4cm from this point along the direction of film travel.
A total of six wire electrodes are placed at intervals. When no voltage is applied to these electrodes at all (Comparative Example 1), when a positive voltage of 5KV is applied to the ground (Comparative Example 2), when a positive voltage of 8.8KV is applied to the ground (Example 1), when the voltage is applied to the ground The adhesion strength with aluminum foil was measured for each of the films obtained when applying a negative voltage of 5 KV to the ground (Example 2) and when applying a negative voltage of 8.8 KV to the ground (Example 3), and the results are shown in Table 1. In addition, the polarity index of each film was measured at the surface layer on the non-casting drum surface side and at the center in the thickness direction.
The polarity index of each surface layer and the polarity index of the center are shown in Table 1. As shown in the table, when the polarity index increases by 1.5% or more, the adhesive strength increases rapidly. In particular, it can be seen that when the amount is 3% or more, the increase in adhesive strength is remarkable. In this case, the amount of polar positive groups increases in both the positive and negative electrodes, which is thought to be due to the polarization as described below. However, polar groups move more easily at the negative electrode. (Polarized state)

[Formula] Examples 4 to 5, Comparison rows 4 to 6 Ethylene/vinyl acetate/glycidyl methacrylate terpolymer manufactured by Sumitomo Chemical Co., Ltd. [trade name "Bond First" 7B, melting temperature 94°C, bending rigidity 300
Kg/cm ² (ASTM D747-63) Vikatsu softening point 78
°C (ASTM D1525−585), tensile strength 190Kg/cm ²
(JIS K6760-1966)] was melted at 220°C using an extruder with a diameter of 40 mm and a L/D of 22, and cast in the same manner as in Example 1. When no voltage is applied to these electrodes at all (Comparative Example 4), when a positive voltage of 5KV is applied to the ground (Example 4), when a positive voltage of 8.8KV is applied to the ground (Example 5), when the voltage is applied to the ground The adhesion strength with aluminum foil was measured for the films obtained in each case, when applying a negative voltage of 5KV (Comparative Example 5) and when applying a negative voltage of 8.8KV to the ground (Comparative Example 6), and the results are shown in Table 1. . In addition, the polarity index of the surface layer on the non-casting drum surface side and the center of each film was measured, and the polarity index of each film is shown in Table 1 as the polarity index of the surface layer and the polarity index of the center. As shown in the table, in this case, it is only effective when applied positively, and it can be seen that when the polarity index increases by 1.5% or more, the adhesive strength increases significantly by 4 to 5 times.

[Table] * Voltage indicates the applied voltage between the electrode and the drum, and "+" and "-" indicate the polarity on the electrode side.

Claims (1)

[Claims] 1. A thermoplastic resin molded product mainly composed of a thermoplastic polymer having a polar group as a side chain, characterized in that the polarity index in the surface layer of the molded product is 1.5% or more larger than the polarity index in the central part in the thickness direction. Plastic resin molding.