JPH0561295B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a laminated polyester molded product with good adhesiveness, and more specifically, a technique for changing the atomic composition of the surface layer of the molded product by corona discharge treatment while transporting the molded product. The present invention relates to a method for obtaining the above-mentioned laminated polyester molded product with excellent adhesiveness by appropriately adjusting the amount. In particular, the advantage of the present invention is that by laminating a layer with high adhesiveness on all or part of the surface of the base layer, a molded product with good adhesiveness can be produced without impairing the heat resistance, transparency, and mechanical properties of the base layer. It's at the point where you can get it. Surface modification of plastic molded articles by corona discharge is generally known as a treatment technique for films, and has had substantial effects such as improved adhesion due to surface activation. However, the results are not completely satisfactory. The present inventors particularly focused on polyester molded products, and for example, when subjecting a polyester film to corona discharge treatment to improve its surface (particularly improve adhesion), it was possible to achieve treatment efficiency that was sufficiently satisfactory at the actual production level. I wanted to establish a method that would allow me to do so. For example, as a corona discharge treatment method for plastic molded products, there is a technique that promotes chemical changes on the discharge surface by supplying an organic solvent to the discharge area, as shown in Japanese Patent Publication No. 17747/1982. It is difficult to apply it to the molded products in question. or
Journal of Applied Polymer Science, Vol.15,
Pages 1365-1375 (1971) describes a technique for performing corona discharge treatment in an inert gas atmosphere, and suggests that the effects of activation or deterioration due to differences in treatment atmosphere may occur. Techniques for processing in place of a low-oxygen atmosphere have also begun to be proposed. However, the implementation techniques that have been proposed so far have various drawbacks as described below. For example, the method disclosed in Japanese Patent Application Laid-Open No. 55-50034 is
The chamber that covers the entire film running space, including the plastic film unwinding reel, take-up reel, and the corona discharge treatment device installed between them, is regarded as one closed space, and the entire atmosphere of the chamber is controlled. This is what we are trying to do.
Therefore, a large amount of inert gas is required, and a special shielding mechanism is required to make the chamber itself a sealed structure, which makes the apparatus complicated and these factors raise the cost. Therefore, as a practical matter, a sufficient inert atmosphere cannot be guaranteed, and it has not yet been possible to freely control the gas composition on the outermost surface of the film. Furthermore, Japanese Patent Application Laid-Open No. 57-23634 discloses that a hood (hereinafter referred to as the first hood) is provided to cover the corona discharge atmosphere to locally control the atmosphere, and another hood (hereinafter referred to as the first hood) is provided in front of the first hood. A control method is disclosed in which a second hood is provided and an inert gas is sprayed onto the traveling film in the second hood. However, with this technology, for example, in Example 2, ``from the slit provided at 45 degrees from the bottom of the pipe toward the film inlet side.''
Supplying CO ₂ into the hood (Note: 2nd hood)
configuration is recommended. From this explanation, it is clear that the inert gas is intended to be supplied into the second hood, and that the gas blown out from the slit hits the inner wall of the second hood and diffuses into the second hood. It is clear that the inert gas is filled inside the hood and covers the film surface, and the publication also states that it is best to avoid blowing out inert gas from directly hitting the discharge electrode, and that the inside of the first hood is It states that the supply of inert gas may be stopped once the gas atmosphere has been replaced with inert gas, and the second hood is expected to play a supplementary role to the first hood. It is clear that it is nothing more than Therefore, this method is more realistic than the technique of replacing the entire atmosphere inside the chamber with an inert gas, but
The studies have only been conducted from the perspective of controlling the entire atmosphere inside the hood, and there is no concept of focusing on the outermost surface of the molded product, which is the most important for corona discharge. Furthermore, in JP-A No. 56-49737, a technique was started in which drying gas is blown into the hood in order to prevent outside air from entering the corona discharge atmosphere.
However, with this technology, the intention is only to suck out the wet gas in the hood and introduce dry gas to perform gas replacement, so to speak, and there is no concept of applying a spot to the outermost surface of the molded product. . The reason why conventional improvement processing methods cannot achieve sufficient results can be considered as follows. In other words, the results of corona discharge appear on the outermost surface of the molded product, and therefore the gas composition at the outermost surface of the molded product is important. They only recognize that it is sufficient to control the gas atmosphere, and they also recognize that it is sufficient to control the gas atmosphere, and that there are obstacles caused by accompanying flow (outside air) on the surface layer of the molded product that is carried in while traveling, that is, the overall gas atmosphere in the chamber and the This seems to be because differences in the gas composition covering the surface are not taken into account. If processing is carried out in a batch-type stationary state, the above-mentioned obstacles will not be a problem, but this will significantly reduce industrial productivity and raise market prices, so in the end it will only be practical for limited applications. cannot be converted into On the other hand, in order to obtain the desired processing effect in the continuous production system as described above, the processing speed must be considerably low, but this will damage the surface of the molded object and cause poor appearance. Problems such as poor adhesion and increased blocking arise. In conventional corona discharge treatment under atmospheric conditions, the surface of the molded product undergoes oxidation and an oxidized deterioration layer is formed on the surface, so even if the degree of corona discharge treatment is increased, the adhesion cannot exceed a certain level. It cannot be improved. The inventors of the present invention have been concerned about this situation for some time and have conducted various studies. As a result, nitrogen gas,
Or mainly nitrogen gas with oxygen content of 20% by volume.
When the following nitrogen-containing composite composition gas is continuously sprayed from the bottom of the discharge side electrode onto the treated surface of the object, the amount of oxygen gas on the surface of the molded object is extremely small, and the effect of nitrogen gas is mainly suppressed. This led to the completion of the present invention after discovering that the treatment effects directly experienced can be obtained. Nitrogen gas or oxygen content 20% by volume
The reason why the corona discharge surface becomes strongly influenced mainly by the nitrogen gas when the following nitrogen-containing composite composition gas gas is sprayed has not been fully elucidated, but the following is tentatively explained. I can think about it. That is, the surface of the molded product transferred to the corona discharge section is accompanied by a considerable amount of air, although it varies depending on the surface characteristics and the transfer speed, and its composition is generally oxygen: 21% by volume, nitrogen: 78% capacity
It is. On the other hand, the composition of the entrained air on the surface of the molded product cannot be easily changed by the above-mentioned ordinary means, such as adjusting the atmosphere in the chamber, but when the above-mentioned blowing means according to the present invention is adopted, the blowing gas is Since part or all of the entrained air layer is expelled and replaced, the composition of the entrained air layer changes.
This change is due to air containing 21% oxygen being replaced by blown gas containing less than 20% oxygen, so the oxygen concentration decreases relatively and the effect of nitrogen gas, which is present as the main component, is reduced. On the contrary, it increases, and an effect that cannot be obtained by conventional corona discharge treatment under an atmospheric atmosphere is exhibited. As mentioned in the above discussion, if the nitrogen gas or oxygen content is
The key point is to continuously spray a nitrogen-containing composite composition gas of 20% by volume or less from the bottom of the discharge side electrode onto the treated surface of the molded product, so gas components other than oxygen and nitrogen include: Regardless of whether it is argon gas, helium gas, carbon dioxide gas, etc.
In either case, the influence of nitrogen gas will be significant. When we attempted to apply the improved corona discharge treatment technology to polyester molded products as described above, we found that there were no inconveniences in terms of blocking or slipping, and the adhesion was significantly improved. It was confirmed that the adhesiveness did not deteriorate even under high temperature and high humidity, and the present invention was completed. That is, the gist of the present invention resides in the following points. At least one molded article is formed by laminating a block copolymer polyester on all or part of the surface of a polyester composed of dibasic acid residues and glycol residues, of which 80 mol% or more is terephthalic acid. When carrying out corona discharge treatment by continuously transferring the material to a corona discharge treatment device comprising a pair of electrodes facing each other, nitrogen gas or a nitrogen-containing composite composition mainly composed of nitrogen gas and having an oxygen content of 20% by volume or less is used. A gas is sprayed onto the corona discharge treated surface of the molded product, and during the spraying, the gas is continuously sprayed along the discharge generation direction from the side of the discharge side electrode facing the molded product. The accompanying air layer carried into the corona discharge treatment apparatus along with the transfer surface of the molded article is destroyed and dispersed and replaced with the blown gas, and a thin layer portion within 100 Å from the outermost surface of the molded article surface is destroyed and dispersed. When the amount of change in the oxygen index and nitrogen index from before corona discharge treatment to after corona discharge treatment is defined as Δoxygen index and Δnitrogen index, the ratio [Δoxygen index/Δnitrogen index] between the two is 1.5 to - 3.5, and the nitrogen index after corona discharge treatment in the thin layer portion is 3 or more. Note that the oxygen index and nitrogen index are determined by the following method. i.e. ESCA spectrometer ES
-200 model (manufactured by Kokusai Electric Co., Ltd.), the integrated intensity was determined from the 1s orbital spectrum of carbon on the surface of the molded product, and the integrated intensity was determined from the peak corresponding to the binding energy of organic nitrogen from the 1s orbital spectrum of oxygen. The number of oxygen per 100 carbon atoms is determined based on the integral ratio, and this value is defined as the oxygen index. Regarding the nitrogen index, the number of nitrogen per 100 carbon atoms is determined by the same method, and this is defined as the nitrogen index. One polyester component (A) of the polyesters targeted by the present invention is composed of a dibasic acid (however, 80 mol% or more of the dibasic acid is terephthalic acid) residue and a glycol residue. It is polyester. This dibasic acid residue is mainly a terephthalic acid residue, but other dibasic acid residues of up to 20 mol% include isophthalic acid, phthalic acid, adipic acid, sebacic acid, succinic acid, oxalic acid, etc. groups, and also residues of oxyacids such as p-hydroxybenzoic acid can be used. In addition, the glycol residue is a normal alkylene glycol residue, and examples thereof include residues such as ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, and cyclohexanedimethanol. Particularly practically, residues of ethylene glycol, tetramethylene glycol, cyclohexanedimethanol are used. A particularly useful polymer is polyethylene terephthalate or polytetramethylene phthalate. The block copolymerized polyester (B) laminated on the polyester (A) is a copolymer consisting of a high melting point crystalline polyester segment (C) and a low melting point soft polymer segment (D) with a molecular weight of 400 to 8000, and the melting point when a high polymer is formed from only the high melting point crystalline polyester segment components is 170°C or higher, and the melting point or softening point when measured using only the low melting point soft polymer segment components is 100°C or lower. A polymer consisting of certain structural units. The high melting point crystalline polyester segment constituent components in the above block copolymerized polyester have a melting point of 170°C or higher when made into a high polymer that exhibits fiber-forming ability by themselves. acid, residues of aromatic dicarboxylic acids such as 1,5-naphthalene dicarboxylic acid and 2,6-naphthalene dicarboxylic acid, and ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, 2,2
- Aliphatic and aromatic compounds such as dimethyltrimethylene glycol, hexamethylene glycol, p-xylylene glycol, and cyclohexanedimethanol,
Or polyester consisting of residues of alicyclic diol, or p-(β-hydroxyethoxy)
In addition to copolymerized polyesters containing residues of oxyacids such as benzoic acid and p-oxybenzoic acid as a copolymerization component on the above polyester, 1,2-bis(4,4-dicarboxymethylphenoxy)ethane , polyether esters consisting of residues of aromatic etherdicarboxylic acids such as di(4-carboxyphenoxy)ethane and residues of diols similar to those mentioned above, bis(N-paracarboethoxyphenyl)terephthalimide, etc. Examples include polyamide esters consisting of aromatic amidodicarboxylic acid residues and diol residues similar to those mentioned above. On the other hand, the low melting point soft polymer segment components include polyethylene oxide glycol, polypropylene oxide glycol, polytetramethylene oxide glycol, copolymerized glycol of ethylene oxide and propylene oxide,
Polyethers such as copolymerized glycols of ethylene oxide and tetrahydrofuran, aliphatic polyesters such as polyneopentyl azelate, polyneopentyl adipate, and polyneopentyl sebacate, polylactones such as poly-ε-caprocratone, polypivalolactone, etc. can be shown. These block copolymerized polyesters can be produced by conventional condensation polymerization methods. Specific examples of the block copolymerized polyester used in the present invention include polyethylene terephthalate-
Polyethylene oxide block copolymer, polytetramethylene terephthalate-polyethylene oxide block copolymer, polycyclohexane terephthalate-polyethylene oxide block copolymer, polycyclohexane terephthalate-polytetramethylene terephthalate block copolymer, polyethylene terephthalate-polytetramethylene oxide block copolymer, polytetramethylene terephthalate-polytetramethylene oxide block copolymer, polytetramethylene terephthalate-polytetramethylene oxide block copolymer, polyethylene terephthalate-polyethylene oxide-polypropylene oxide block copolymer, polyethylene terephthalate-poly -ε-Caprolactone block copolymer, polytetramethylene terephthalate-
Poly-ε-caprolactone block copolymer, polyethylene terephthalate-polypivalolactone block copolymer, polyethylene terephthalate-polyethylene adipate block copolymer, polyethylene terephthalate-polyneopentyl sebacate block copolymer, polytetramethylene terephthalate polyethylene dodecanate block copolymer, polytetramethylene terephthalate-polyneopentyl decanate block copolymer, block copolymer of polyester from di(4-carboxyphenoxy)ethane and ethylene glycol and polyethylene glycol, Examples include a block copolymer of polyethylene glycol made from bis(N-baracarboethoxyphenyl)adipamide and ethylene glycol. It is recommended that the low melting point soft polymer segment (D), which is a component of the block copolymerized polyester (B), be present in an amount of 0.1 to 60% by weight based on the total weight of the ester (B). That is, when the content of the low melting point soft polymer segment (D) is less than 0.1% by weight, the polyester becomes substantially a high melting point crystalline polyester segment alone, so there is no difference from the polyester (A), and polyester single molding is performed. Defects of products (for example, in the case of film, the bends are easily subject to stress concentration, resulting in pinholes, or become brittle due to shrinkage or deterioration during high-temperature processing, etc.)
It becomes difficult to obtain the benefits of improving However, if the content of the low melting point segment (D) exceeds 60% by weight, this segment is generally amorphous, resulting in undesirable strength. In addition, from the viewpoint of the lamination ratio of polyester (A) and block copolymerized polyester (B),
As the ratio of the latter (B) increases, the transparency decreases, so in the case of film or sheet applications, the ratio of the latter is preferably 50% by weight or less. In the case of other molded products that do not require transparency, the amount may be increased further, but from the viewpoint of economy, it is preferable to set the upper limit to 80% by weight. Examples of other molded products include fibers, pipes, tapes, woven fabrics, nonwoven fabrics, and the like. When obtaining a laminate molded product using both polyesters (A) and (B), other polymers may be further blended within the range that does not adversely affect the properties of each layer. For example, polyester ( A), (B)
may be mixed with each other. In this case, the latter (B)
It is common to keep the mixing rate up to about 30% by weight.
Beyond this, the properties of the base polymer are impaired. When blending polymers other than polyester, it is desirable that the content be 30% by weight or less so as not to impair the properties of the polyester. In addition to polymer components, stabilizers, lubricants, anti-blocking agents, anti-fog agents, ultraviolet absorbers, twist retardants, clarifying agents, antioxidants, light stabilizers, and antistatic agents are added based on the type and purpose of the molded product. The present invention may contain additives such as agents, dyes, and pigments, and all additives that do not adversely affect the implementation of corona discharge are included in the scope of the present invention, regardless of whether they are used alone or in combination. In producing polyester molded articles using a polyester composition made of the above-mentioned materials, it is sufficient to follow a known method for each molded article. will not deviate from the scope. Therefore, the method for producing the molded article may be freely selected, but since a typical molded article to which the present invention is applied is a film, the method for producing the film will be explained as follows. That is, there are methods such as preparing the composition raw materials of each polyester (A) and (B) separately, forming films separately and then laminating them together, and laminating them at the same time as the film formation. The film forming method is as follows:
Examples include the T-die method and the inflation method.
The latter film forming and laminating means include a method of extruding and laminating layers by co-extrusion, a method of extruding from an independent separate die and laminating, and a method of extruding onto one film that has already been formed. The method of laminating the layers is shown. The obtained film is 1
It is recommended to improve the strength by stretching in the axial or biaxial direction. The corona discharge treatment described below may be performed as one of the entire film forming process at the latter stage of the stretching process, and in some cases, the corona discharge treatment may be carried out while the once-rolled product is being re-rolled. In some cases, a method of applying In the present invention, the above-mentioned polyester molded product is treated, and the molded product is continuously transferred to a corona discharge treatment device having at least one pair of electrodes facing each other to produce a laminated surface, that is, a surface of the laminated polyester (B). During this treatment, the surface to be treated is treated with nitrogen gas, or a nitrogen-containing composite composition mainly composed of nitrogen gas and with an oxygen content of 20% by weight or less [specifically, some of the oxygen from the air is removed]. N ₂ alone or with H ₂ , Ar,
A mixture of inert gas or ionic gas such as CO ₂ , Xe, Kr, CI ₂ , NH ₃ , _NO Spray continuously. During the spraying, the gas is sprayed from the side of the discharge-side electrode facing the molded product along the discharge generation direction. That is, the direction of the blowing is an important point in the present invention, and by blowing the blowing gas from almost directly above the molded object, it becomes possible to destroy and disperse the entrained air layer. Further, it is desirable that the spraying speed be 1% or more of the transport speed (conveyance speed) of the polyester molded article. As will be explained in detail later, the relationship between the oxygen index and nitrogen index before and after corona discharge treatment in the thin layer within 100 Å from the outermost surface of the surface to be treated (the region that has an important effect on adhesion) is strictly specified. By doing so, it has extremely excellent adhesion to various materials (e.g., metals; various inks, especially cellulose-based inks, water-based inks, etc.; resins, such as vinylidene chloride alone or copolymers, functional group-containing resins, etc.). A polyester molded product can be obtained. The structure and effects of the present invention will be clarified below based on the drawings of the embodiments, but the structure and arrangement of the discharge side electrodes and the shape of the cover shown in the drawings are only representative examples. Since the above is merely an example of application to plastic film, it is within the technical scope of the present invention to change the design on the condition that it does not go against the spirit of these descriptions. FIG. 1 is a sectional view of the main parts showing the implementation concept of the present invention,
FIG. 2 is a perspective view showing a part of the discharge side electrode, in which 1 is a metal drum, 2 is an electrode cover, and 3 is a perspective view showing a part of the discharge side electrode.
Reference numeral indicates a discharge side electrode, 4 indicates a gas supply pipe, 5 indicates a gas outlet, and 6 indicates a running film. That is, the film 6 is introduced from the direction of the arrow B into the metal drum 1 rotating in the direction of the arrow A, and further travels in the direction of the arrow C. , applying a high voltage of several thousand to tens of thousands of V at a high frequency of several hundred KC/S between the metal drum 1 covered with polyester, epoxy resin, ceramic, chlorosulfonated polyethylene, EP rubber, silicone rubber, etc. For example, in the natural atmosphere, ozone and nitrogen oxide are generated under the influence of high-pressure corona generated by the film 6, and carbonyl groups and carboxyl groups are generated on the surface of the film 6, thereby polarizing the surface. On the other hand, in the conventional example, oxygen in the atmosphere generates oxidized deterioration products on the film surface that inhibit adhesion.
However, in this example, the entire corona discharge atmosphere is shielded from the atmosphere by the electrode cover 2, and a slit-shaped gas outlet 5 is provided on the bottom of the discharge side electrode 3 and directed toward the surface of the film 6. Since the structure is such that the inert gas is sprayed almost vertically from the bottom surface of the discharge side electrode 3, the accompanying air layer covering the surface of the molded product is destroyed, and the air layer is controlled by the composition of the sprayed gas. The surface of the molded product is covered by the low-oxygen atmosphere (inside the electrode cover 2), which substantially reduces the oxygen content in the coating gas, thereby increasing the influence of nitrogen gas. As a result, the corona discharge effect on the surface layer of the film 6 can be maximized. This situation will be explained in more detail as follows.
That is, on the surface of the film 6 that enters at a fairly high speed along the direction of arrow B, a small amount of entrained air layer is formed, and this can be removed simply by following the conventional method to completely eliminate the entire atmosphere of the corona discharge area. If only the active gas is substituted, the outermost surface of the film 6 remains in an atmospheric atmosphere. Therefore, in carrying out the present invention, inert gas is strongly blown onto the film surface from the direction shown in FIG. 3, and the entrained air layer 7 is destroyed and dispersed by the jet stream 8. Therefore, the gas composition in the accompanying air layer 7 on the film surface is changed to increase the proportion of nitrogen gas. In some cases, the surface can be almost completely replaced with an inert gas. The flow velocity of the jet stream 8 necessary to destroy and disperse the entrained air layer 7 to obtain the above effect cannot be determined uniformly because it varies depending on the shape and dimensions of the molded product, the speed at which it is carried into the corona discharge treatment equipment, etc. However, as a result of experiments, it has been found that it is most preferable to set the speed based on the speed of entry of the entrained air layer 7 (in other words, the speed of transport of the molded product). Since it is generally convenient for understanding that the gas blowing speed is expressed in seconds and the film transport speed is expressed in minutes, such a convention will be followed in the present invention. That is, it is desirable to continuously spray the gas so that the value of the blowing gas velocity expressed in seconds is 1% or more of the value of the transfer velocity of the molded article expressed in minutes, but preferably 10%. If the ratio is more preferably 40% or more, the entrained air layer 7 can be destroyed and dispersed to the extent that there is no substantial problem. The angle at which the ejected gas is blown onto the film can be freely selected depending on the effective angle. The speed at which the molded product is carried in is generally 1 to 500 m/min. By adopting such conditions, it becomes possible to destroy and disperse the accompanying air layer, and at the same time, it becomes possible to protect the vicinity of the corona discharge part with an inert gas atmosphere, as shown in Figure 1. The electrode cover 2 shown in 2 has a primary function of protecting the electrode 3 from mechanical impact rather than an atmosphere maintenance function, and a secondary function of suppressing the accompanying flow. . Therefore, when carrying out the present invention, the electrode cover 2 may be removed from time to time, but in order to suppress the consumption of inert gas, it is desirable to reconsider its function for maintaining the atmosphere. As shown in FIG. 4, if the lower end (film side) of the cover 2 is squeezed and the inert gas is introduced into the cover 2 from the conduit 10 at the same time, the gas will converge along the inner surface of the slope 9. The gas flows in the direction of the arrow as shown, and a gas curtain effect is exerted at the inlet of the cover 2. That is, the intrusion of the entrained air layer is blocked on the inlet side, and the existence value of the electrode cover 2 is further improved. Furthermore, as shown in FIG. 5, if an extension cover 11 is provided particularly at the inlet and brought close to the surface of the molded product, the extension cover 11 will be filled with inert gas leaking from inside the cover 2. Therefore, the accompanying air layer that has entered through the cover 11 is also destroyed and dispersed little by little as it progresses inside the cover 11. Therefore, when the corona discharge reaches the atmosphere, the degree of substitution with the inert gas is extremely high.
The effects of the present invention are more clearly exhibited. When using the device shown in Fig. 5, the inert gas can also be sprayed from the extension cover 11, and the spray angle can be freely selected, but in any case, the inert gas can be sprayed directly at the film introduction part. is sprayed, so
The destruction and dispersion efficiency for the accompanying air layer is extremely high. On the other hand, on the exit side of the film 6 (the right side in Fig. 4), the gas inside the cover 2 is discharged along with the traveling film 6, so the sealing performance or the mechanism for blocking atmospheric intrusion should be given as much consideration as on the entrance side. Although it is not necessary to do so, it is meaningful to take the same consideration as on the inlet side in terms of reducing the amount of inert gas consumed as described above. In order to achieve the above-mentioned sealing function on the inlet and outlet sides of the cover 2 to the minimum extent, the film travel speed must be at least 0.2% or more, preferably 10%.
It is desirable to release the film onto the film surface at a speed higher than that. Regarding the ejection speed of the inert gas, only the lower limit side has been described for both the gas ejection port 5 and the inlet/outlet of the cover 2, but there is no practical need to set an upper limit on the ejection speed, and it is based on economic efficiency and the required quality of the final product. It should be decided appropriately based on the balance. By setting the processing conditions as described above, the processing effect of corona discharge is enhanced and the adhesion is greatly improved. We proceeded with further research based on the belief that it was necessary to quantitatively understand the surface characteristics before and after. As a result, (1) the ratio of changes in the oxygen index and nitrogen index before and after corona discharge treatment in a thin layer within 100 Å of the surface of the workpiece [Δoxygen index/Δnitrogen index], and (2) It has been found that a high degree of adhesion can be ensured by strictly controlling the nitrogen index after corona discharge treatment in the thin layer within 100 Å of the surface.
In other words, the above-identified facts are that for (1) above, [Δoxygen index/Δnitrogen index] will be 1.5 to -3.5, and for (2) above, that the nitrogen index after treatment will be 3 or more. By strictly controlling the processing conditions and processing atmosphere of corona discharge,
For example, it can dramatically improve adhesion to metals, various printing inks (especially cellulose-based inks, water-based inks, etc.), various synthetic resins such as vinylidene chloride alone or copolymer resins, and functional group-containing resins. This will be explained in more detail below. First, a polyester molded product that satisfies the requirement of [nitrogen index ≧3] specified in the present invention can sometimes be obtained using conventional processing conditions, and can also be obtained by known corona discharge treatment in a nitrogen gas atmosphere. It is possible. However, as explained earlier, in order to ensure the above-mentioned high level of nitrogen index using the conventional method, which is intended for continuous processing at least, large-scale equipment is required, making it difficult to put it into practical use on an industrial scale. Ta. On the other hand, if the method of the present invention is adopted,
The nitrogen index can be easily increased to 3 or more with relatively simple equipment. On the other hand, there are also reports that the adhesion of plastic materials to various materials is simply determined by the nitrogen index determined by the ESCA method.
However, such reports capture only one aspect of the influence on adhesion. By the way, if you blend an N component into the material, the nitrogen index will increase, but if you consider the fact that just mixing antistatic agents and lubricants, which are N-containing components, will not improve the adhesion, it will actually decrease. It is clear that an increase in nitrogen index does not directly correlate with adhesion. Therefore, we investigated other factors that affect adhesion and found the above [Δoxygen index/Δ
The value calculated by [Nitrogen Index] almost accurately represents the effect of corona discharge treatment, that is, the effect of improving adhesion, and products that have been treated such that this value is 1.5 to -3.5 have a high level of adhesion that meets the purpose. The fact that it works has been confirmed. By the way, even if the nitrogen index within 100 Å of the surface layer after treatment is 3 or more, [Δoxygen index/Δnitrogen index] is 1.5.
If it exceeds this amount, the corona discharge treatment effect will be insufficient and a high level of adhesion cannot be obtained. In this sense, it is essential to adopt the treatment method of the present invention and to control the treatment conditions so that the nitrogen index is 3 or more and [Δoxygen index/Δnitrogen index] is 1.5 to −3.5. Note that it was practically extremely difficult to reduce this ratio to less than -3.5. By the way, regarding [Δ oxygen index / Δ nitrogen index], oxygen atoms constituting polyester, oxygen atoms in other polymers that may be blended, or specific oxygen atoms in various additives are released and removed by inert gas. , or may be replaced and removed by nitrogen atoms in an inert gas, resulting in a negative value as described above. In this negative range, generally in the range of -1.0 to 0, favorable results can be obtained in that the change in adhesive strength over time is extremely small and the blocking resistance is improved. The present invention is roughly constructed as described above, and the corona discharge treatment conditions are specified, and the treatment effect is constantly grasped from the amount of change in the oxygen index and nitrogen index of the surface layer before and after treatment. It has become possible to reliably obtain polyester molded products with excellent adhesiveness to various materials. In particular, the effect of improving adhesion is exhibited even after long-term exposure to high temperature and high humidity, and the surface layer with improved adhesion is not easily peeled off from the base layer, so for example, molded When it is a film, there is no possibility that the above-mentioned surface layer will be transferred to the back side during winding and storage, and there is no fear that the printing ink will peel off when it is actually applied as a film package. Furthermore, since the adhesion to other film base materials is improved, there is no possibility that the laminated films will peel off after long-term storage. Next, experiments will be carried out to clarify the effects of the present invention. The method for evaluating surface properties adopted in the experimental examples is as follows. (A) Haze Measured according to JIS-K-6714 (B) Lamination strength Printed using cellophane ink, coated with polyethyleneimine, dried, and melt-extruded low-density polypropylene at 290°C to a thickness of 30 μm. Laminate with. Immediately after storage or treatment under various conditions, the film and polypropylene layer are peeled off and the adhesive strength is measured. The peeling conditions are 180 degree peeling and speed 200.
mm/min. However, products treated with boiling water and retort were laminated using an isocyanate adhesive, and after lamination, they were aged at 40°C for 2 days before evaluation. Film manufacturing example (A) Polyethylene terephthalate (intrinsic viscosity
0.65 dl/g) (B) 83 parts of dimethyl terephthalate, 110 parts of 1,4-butanediol, 215 parts of poly(tetramethylene oxide) glycol (PTG) with a molecular weight of 2000.
and 0.6 parts of an antioxidant (Ionox 330: manufactured by Shell Chemical Co., Ltd.) and tetra-n- as a catalyst.
Add 0.03 part of butyl titanate, heat in an autoclave while stirring to transesterify, and then polycondensate to obtain a polytetramethylene terephthalate-polytetramethylene oxide block copolymer (molar ratio of terephthalic acid and PTG: 4:1). ). A laminated film is obtained by coextruding the above (A) and (B).
Subsequently, the unstretched film was heated at 90°C in the longitudinal direction for 3.2
Stretched 3.5 times in the transverse direction at 95℃, and then stretched 3.5 times in the transverse direction at 230℃.
Heat set for seconds, and the thickness was 12 μm [(A) component was 10 μm,
A biaxially stretched film having component (B) of 2 μm was obtained. The film obtained above was subjected to corona discharge treatment using the apparatus shown in FIG. 1 under the conditions shown below. Examples (1) to (3) of the present invention are cases in which a gas mixture of nitrogen gas and air is supplied from the gas supply pipe 4, and corona discharge is performed while continuously spraying from the gas outlet 5. In Comparative Example (1), nitrogen gas was supplied into the electrode cover 2 and the discharge atmosphere was the same (O ₂ =0.1%) as in Inventive Examples (1) and (2), but Comparative Example (2) is a case in which corona discharge treatment was performed in the general atmosphere, and Comparative Example (3) is a case in which the electrode was not sprayed as shown in Figure 6. A gas supply pipe 4 is installed on the top of the cover 2, and a pipe with a blowout slit at a 45-degree angle from directly below toward the film inlet side is installed inside the electrode cover 2', and gas is supplied from both. be. ESCA values are also listed in Table 1. When the haze and lamination strength of the corona discharge treated film were determined, the results shown in Table 2 were obtained.

【table】

【table】

[Table] As is clear from Tables 1 and 2, Comparative Examples (1) to (3) have low [Nitrogen Index after treatment], and Comparative Example (2) has [ΔOxygen Index/ΔNitrogen Index] is getting higher,
Atmospheric removal from the film surface is insufficient. In contrast, in Examples (1) to (3) of the present invention, the [nitrogen index after treatment] is 3 or more, and the [Δoxygen index/Δnitrogen index] is 1.5.
It can be seen that the adhesiveness is within the range of -3.5 and has excellent adhesiveness. In other words, by adopting the configuration of the present invention, it is possible to remove the accompanying air layer on the film surface for the first time, and it is confirmed that removal of the accompanying air cannot be achieved by simply changing the discharge atmosphere to a nitrogen atmosphere. It was done.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram showing the implementation status of the present invention, Figure 2
The figure is a sketch diagram illustrating the discharge-side electrode used in the present invention, Figure 3 is an explanatory diagram showing the state of destruction of the accompanying air layer, Figures 4 and 5 are explanatory diagrams showing an example of the electrode cover, and Figure 6 is a comparison. FIG. 7 is a conceptual diagram showing the implementation status of example (3). 1...metal drum, 2...electrode cover, 3...
Discharge side electrode, 5... gas jet port, 6... film.

Claims (1)

[Scope of Claims] 1 Molded by laminating a block copolymer polyester on all or part of the surface of a polyester composed of dibasic acid residues and glycol residues, of which 80 mol% or more is terephthalic acid. The molded product is
When continuously transferring to a corona discharge treatment device consisting of at least one pair of electrodes facing each other and performing corona discharge treatment on the laminated surface, nitrogen gas or nitrogen gas as the main component with an oxygen content of 20% by volume or less A nitrogen-containing composite composition gas is sprayed onto the corona discharge treated surface of the molded product, and during the spraying, the gas is continuously applied from the side of the discharge side electrode facing the molded product along the discharge generation direction. By spraying on the surface of the molded article, the accompanying air layer carried into the corona discharge treatment apparatus along with the transfer surface of the molded article is destroyed and dispersed and replaced with the blown gas. When the amount of change in the oxygen index and nitrogen index in the thin layer portion within 100 Å from before corona discharge treatment to after corona discharge treatment is defined as Δoxygen index and Δnitrogen index, the ratio between the two [Δoxygen index/Δnitrogen index] 1. A method for producing a highly adhesive multilayer polyester molded product, characterized in that the nitrogen index after corona discharge treatment in the thin layer portion is 3 or more. (Here, the oxygen index and nitrogen index are determined by the following method: ESCA spectrometer ES
-200 model (manufactured by Kokusai Electric Co., Ltd.), the integrated intensity was determined from the 1s orbital spectrum of carbon on the surface of the molded product, and the integrated intensity was determined from the peak corresponding to the binding energy of organic nitrogen from the 1s orbital spectrum of oxygen. The number of oxygen per 100 carbon atoms is determined based on the integral ratio, and this value is defined as the oxygen index. Regarding the nitrogen index, the number of nitrogen per 100 carbon atoms is determined by the same method, and this is defined as the nitrogen index. )