JPH10139900A - Processing of resin surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for processing a resin surface by which a deterioration is extensively prevented and a toughness is maintained by irradiating a specific accumulated interference pattern on the surface of a processed material comprising a resin. SOLUTION: A punctual or thready accumulated interference pattern 6 (a pitch between dots or lines are preferably 0.02-5mm) obtained by injecting a laser beam 1 into cylindrical interfering optical system 3 is irradiated on a surface of a material to be processed such as a film, at least the surface of which comprises a resin such as a polyolefin-based resin and a polyester-based resin and the resin surface is processed by performing interference pattern processing on the resin surface. The part processed by the interference pattern processing is preferably the part to be readily destroyed in the material to be processed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a resin surface using a laser beam, and more particularly to a method for utilizing a point-like or linear collective interference pattern for processing a resin surface.

[0002]

2. Description of the Related Art A laser beam has a high energy density, and it has been known for a long time to use it for processing for cutting / separating a metal or the like or removing holes and the like. It is also known to use laser beams for metal surface modification, such as surface hardening (quenching), rapid solidification (glazing), surface alloying and amorphous layer formation, surface concentration and surface deposition. ing.

[0003] It is already known to process a packaging material such as plastic using a laser beam.
JP-A-60-89365 discloses a piercing-resistant material surface of a laminated material in which a heat-adhesive resin is laminated on one surface of an aluminum foil and a piercing-resistant material such as a plastic film is laminated on the other surface. In, having an opening of a desired shape, and through an aperture mask and a focusing lens made of a material that blocks light, is irradiated with carbon dioxide laser light,
A method is described for removing a portion of a piercing resistant material layer into the desired shape.

Japanese Patent Application Laid-Open No. 62-222835 discloses that after forming a blank of a liquid paper container, a carbon dioxide gas laser is irradiated in a substantially horizontal direction over the entire periphery from the surface layer to the vicinity of the upper end side of the vertical wall of the blank. A method for manufacturing a liquid paper container characterized by forming an opening line composed of a thin groove having a width of about 1 mm.

Further, Japanese Patent Application Laid-Open No. 4-327139 discloses a packaging bag having heat-sealed portions at both end edges, each of which has a tear guiding groove formed at a position corresponding to each other on the front and back surfaces of the packaging bag. About one edge from the side edge of the heat-sealed portion.
It describes an easy-open packaging bag that is positioned at an interval of at least mm, and also describes that the guide groove is formed by a laser.

[0006]

However, the formation of an opening line, a tear-inducing groove or a layer for removing a polymer in a polymer material such as plastic has not yet been put to practical use, although there are many proposals. The fact that it does not reach the area gives a very strange feeling, but this is because the irradiation of high energy density such as a laser beam does not excessively weaken the packaging material etc. It is considered that the reason is that it is difficult to form) in a stable and controlled state, and that the polymer is deteriorated by laser beam irradiation.

For example, as shown in a comparative example described later, nylon (15 μm) / linear low-density polyethylene (130
In the case of performing a score processing with a laser beam on a laminated film of (μm), the yield point strength in the direction perpendicular to the score is adjusted by adjusting the energy and performing slit exposure.
It is possible to process 5 to 3.1 kgf,
In this case, there is a problem that the elongation (strain) is reduced to 10% or less, and the toughness (tenacity) of the processed portion is greatly reduced.

One of the causes is considered to be that the energy density of the laser beam is too high. As a means for avoiding this, it is conceivable to use the laser beam by defocusing it. Even in the state, the energy distribution is Gaussian distribution which is high at the center and decreases as it goes to the periphery, so again,
The effects of polymer degradation are difficult to avoid.

Further, as means for irradiating a laser beam only to a limited portion of a work material, Japanese Patent Application Laid-Open No.
No. 9365 discloses a masking method. However, in this case, since the light is absorbed and reflected by the mask, the energy efficiency is reduced, and the method is not yet satisfactory.

Accordingly, an object of the present invention is to prevent the deterioration of the resin as much as possible and to effectively use the energy of the laser beam when processing a workpiece whose surface is made of a resin with a laser beam. It is to provide a processing method.

[0011]

According to the present invention, a point-like or linear collective interference pattern obtained by irradiating a laser beam into a tubular interference optical system is used to form a workpiece having at least a surface made of resin. A method for processing a resin surface, comprising irradiating the surface with a resin and subjecting the resin surface to interference pattern processing is provided.

In the method of processing a resin surface according to the present invention, a laser beam is incident on a tubular interference optical system to form a point-like or linear collective interference pattern, and this point-like or linear collective interference pattern is covered. It is characterized by irradiating the surface of the processed material.

The tubular interference optical system is generally called a kaleidoscope. The tubular interference optical system is formed of a tubular body whose inner surface is a mirror. When a laser beam is incident on the inner surface, multiple reflection by the mirror surface is performed. A point-like or linear collective interference pattern is formed. In addition, this point-like or linear collective interference pattern has the advantage that the intensities of the respective peaks are substantially uniform.

In FIG. 1 for explaining the principle of generation of a point-like or linear collective interference pattern, a laser beam 1 is condensed by a condenser lens 2 and made incident on a tubular interference optical system 3. The tubular interference optical system (callidescope) 3 is a metal tubular body, has holes 4 of various cross sections in the vicinity of the center, and the inner surface 5 is plated with gold having high reflectivity. Is what it is. In the portion where the wavelength of the laser light reflected by the inner surface 5 is shifted by an integral multiple, the light overlaps,
In the portion shifted by half a wavelength, the lights cancel each other out, and a fine interference pattern 6 having peaks at substantially the same height is formed.

Considering the case of irradiating a laser beam normally, as shown in FIG. 2, it is usual to focus on the position of the workpiece 7 via the condenser lens 2 (f).
In this case, the intensity distribution of the laser beam has a steep Gaussian distribution as shown by a curve a in FIG. Therefore, the width is narrow (half width H ₀ ), the strength at the center is high, and the surface temperature of the workpiece 7 is high. On the other hand, in FIG. 2, it is conceivable to irradiate the workpiece 7 with the laser beam 1 by shifting the focus position by f ₀ (defocusing). In this case, too, the curve b shown in FIG. As described above, it is inevitable that the Gaussian distribution becomes smooth as a whole, but the central portion is strong and the peripheral portion is weak.

On the other hand, according to the present invention, by utilizing the interference of the laser beam, the laser beam is divided into a number of peaks in the width direction as shown in FIG. The height is uniformly suppressed to a low level, which brings a great advantage to the processing of a workpiece whose surface is made of resin.
That is, it is possible to prevent the resin from being locally heated to a high temperature, to prevent the generation of fumes, to prevent the resin from being thermally decomposed or deteriorated, and to perform a large-area processing on the workpiece. In addition, according to the present invention, substantially all of the energy of the laser beam can be used for processing the resin, and there is an advantage that there is no energy loss unlike the case of using a pattern mask.

In the interference pattern with respect to the resin, generally, of the point-like or linear collective interference pattern, a molten portion or a relative concave portion of the resin is formed corresponding to the same phase portion, and corresponding to the opposite phase portion. As a result, a non-melted portion or a relative convex portion of the resin is formed, and an extremely unique structure or structure can be formed on the surface of the workpiece. By forming such an interference pattern on the resin surface, it is possible to effectively suppress a decrease in toughness of the processed resin.

That is, a laminated film of nylon (15 μm) / linear low-density polyethylene (130 μm) is processed by ordinary slit exposure so that the yield point strength in the direction perpendicular to the score becomes 2.5 to 3.1 kgf. It has already been pointed out that the elongation (strain) is reduced to 10% or less and the toughness (tenacity) of the processed part is greatly reduced when performing the same method. The elongation of 20% or more can be maintained and the toughness of the processed part can be maintained twice or more. This effect is not limited to this laminated film, but can be similarly obtained with various other films. For example, in polyethylene terephthalate (12 μm) / aluminum foil (7 μm) / polypropylene (25 μm),
1.5 to 2 times the toughness at yield point strength and about 2 times toughness at yield point strain.

The present invention can be widely applied to an interference pattern processing of a work material having at least a surface made of resin, and this interference pattern processing is, for example, easy to break such as a score portion or a tear start portion of the work material. Formation of heat-resistant part, formation of heat-seal part of work material, formation of non-slip part of work material, formation of blocking prevention part of work material such as label, on the sliding surface of work material such as ski and sled Formation of a water-repellent part, formation of a laminar flow-inducing part at a part in contact with a fluid of a work material, formation of a part for improving abrasion resistance of the work material, formation of a temporary label sticking part for easy peeling of the work material The present invention can be applied to formation, formation of a decorative portion of a work material, formation of an opaque portion of a work material, formation of a foamed heat insulating portion, and the like.

[0020]

DETAILED DESCRIPTION OF THE INVENTION

[Workpiece] The resin forming the surface of the workpiece may be a thermoplastic resin or a thermosetting resin.

Examples of the thermoplastic resin include low-density polyethylene, high-density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene, ethylene, propylene, 1-butene, 4-methyl-1-pentene and the like. Polyolefins such as random or block copolymers of α-olefins, ethylene / vinyl acetate copolymers, ethylene / vinyl alcohol copolymers, ethylene / vinyl compound copolymers such as ethylene / vinyl chloride copolymers, and polystyrene Styrene resins such as acrylonitrile / styrene copolymer, ABS, α-methylstyrene / styrene copolymer, polyvinyl chloride, polyvinylidene chloride, vinyl chloride / vinylidene chloride copolymer, polymethyl acrylate, polymethacrylic acid Polyvinyl compounds such as methyl, Ron 6, Nylon 6-6, Nylon 6-10, Nylon 11, Nylon 12 or other polyamide, thermoplastic polyester such as polyethylene terephthalate or polybutylene terephthalate, polycarbonate, polyphenylene oxide or a mixture thereof. May be. Olefin resins, polyester resins, polyamide resins, styrene resins or vinyl chloride resins are particularly preferred.

On the other hand, examples of the thermosetting resin include phenol-formaldehyde resin, furan-formaldehyde resin, xylene-formaldehyde resin, ketone-formaldehyde resin, urea-formaldehyde resin,
Examples include melamine-formaldehyde resin, alkyd resin, unsaturated polyester resin, epoxy resin, bismaleimide resin, triallyl cyanurate resin, thermosetting acrylic resin, silicone resin, urethane resin and the like. These resins may be used alone or in combination of two or more.

Suitable examples of the workpiece whose surface is made of a thermoplastic resin include one or more thermoplastic resins, thermoplastic resins and other materials, such as metal foils or sheets, paper, nonwoven fabrics or woven fabrics, and glass. Film or sheet consisting of a laminate with the like; bags or pouches, cups, trays, bottles, tubes, cans, containers such as tanks; container caps such as various caps, crowns, can lids; panels, pipes, housings, sashes and the like Various structural materials.

The thermoplastic resin present on the surface may be unoriented or amorphous, or may be thermally crystallized or may be oriented and crystallized in uniaxial or biaxial directions. Thermo-crystallized or oriented crystallized thermoplastic resin has a higher melting point than unoriented or amorphous one, and is susceptible to thermal degradation by ordinary heating, but in the processing method of the present invention, Processing becomes possible while suppressing deterioration of the resin, which is advantageous.

Suitable examples of the work material whose surface is at least made of a thermosetting resin include a molded article made of the thermosetting resin exemplified above, and a paint made of the thermosetting resin applied to a base such as a metal. It is a coated structure.

[Laser Beam and Tubular Interference Optical System] In the present invention, a laser beam is passed through a tubular interference optical system (callidescope) to form a point-like or linear collective interference pattern. Perform processing.

In the present invention, the laser beam is
A carbon dioxide laser is used, and its output is generally 10
Those in the range of W to 1.2 KW are suitable, but of course are not limited to this.

As described above with reference to FIG. 1, the tubular interference optical system is a metal tubular body, has holes of various cross sections in the vicinity of the center, and the inner surface is made of gold plating having high reflectivity. It has been applied. By condensing the laser beam with a condensing lens, especially a planoconvex lens, and making it incident on the tubular interference optical system, the light overlaps where the wavelength of the laser light reflected on the inner surface is shifted by an integer multiple, In the portion shifted by half a wavelength, the lights cancel each other out, and a fine interference pattern having peaks at almost the same height is formed.

The cross-sectional shape of the hole of the tubular interference optical system may be a polygon such as a triangle, a quadrangle, a pentagon, a hexagon, an octagon, a circle, an ellipse, or the like.
The outer shape of the point-like or linear collective interference pattern is determined.

That is, as shown in FIG. 4, the laser beam at the exit of the kaleidoscope, when the cross section of the cavity is a square, is a point-like set beam in which the outer shape is a square and each dot is aligned vertically and horizontally. It becomes 10. In addition, when the cross section of the hollow portion is circular, as shown in FIG. 5, a linear aggregate beam 11 in which the outer shape is circular and each line is arranged concentrically is obtained. Further, as shown in FIGS. 6 and 7, if the cross section of the hollow portion is a triangle or a hexagon, the outer shape is a triangle or a hexagon, and dots are arranged in parallel with the sides of the triangle or the hexagon. Collected beams 12 and 13 are obtained.

In the point-like or linear collective beam from the kaleidoscope, the distance and size of each point or line are determined by the distance from the outlet of the kaleidoscope to the workpiece (the distance increases as the distance increases, but the distance increases). , Strength decreases)
And the dimensions of the cross section and the length of the kaleidoscope. When the length of the kaleidoscope becomes long, the intensity of the interference pattern is averaged, and becomes closer to a rectangular intensity distribution.
This strength pattern can be used to improve abrasion resistance, scratch resistance, solvent resistance, etc. by promoting partial crosslinking of the thermosetting resin film.

It is also possible to change the size of the entrance and the size of the exit of the cavity of the kaleidoscope, which has the advantage of being able to work over a very large area.
For example, as shown in FIG.
With a size of 3 mm and a size of the outlet 22 of 18 mm × 3 mm, the size of the point-like aggregate beam is about 5 mm × 20.
mm. Further, as shown in FIG. 8B, the pattern of the point-like collective beam becomes a point-like or linear collective interference pattern 14 elongated in the longitudinal direction of the outlet.

When the kaleidoscope 3 is tilted from the optical axis of the planoconvex lens 2 as shown in FIG. 9A, the interval between the points increases in the tilting direction as shown in FIG. 9B. A point-like aggregate beam 15 is obtained.

In the present invention, the pitch between the points or lines of the point-like or linear collective interference pattern is 0.02 to 5
mm, particularly preferably in the range of 0.05 to 2 mm. When this pitch is smaller than the above range, it is difficult to process an interference pattern corresponding to a point-like or linear collective interference pattern, for example, it is difficult to heat the surface resin in a pattern, and the entire surface is uniformly heated. It tends to be. On the other hand, if it is larger than the above range, the interference pattern tends to be too rough and the effect of processing cannot be obtained.

It is preferable that the point-like or linear collective interference pattern has a dimension of at least 1 mm or more, particularly 2 mm or more in at least one direction. That is, the present invention is advantageous in that a relatively large area can be processed by one laser irradiation. However, if the size is smaller than the above range, the processing efficiency is reduced.

Further, it is preferable that the point or linear collective interference pattern has an incident energy corresponding to 3 to 40 J, particularly 5 to 25 J per unit area (1 cm ² ). If the incident energy is smaller than the above range, it is difficult to form a processing pattern such as melting of a resin even at a position irradiated with a point-like or linear beam. On the other hand, if it is larger than the above range, the influence of deterioration of the resin and the like becomes large. According to the present invention, it is possible to perform heating to such an extent that the outer surface resin is melted but not substantially scattered, thereby preventing loss of the resin material and excessively reducing the toughness of this portion. It is possible to perform processing for easy tearing or the like without occurring in the above.

[Interference Pattern Processing] In the present invention, the interference pattern processing can be performed while the point- or line-shaped collective interference pattern and the workpiece are relatively stationary. The interference pattern processing can also be performed by relatively scanning the collective interference pattern and the workpiece.

For example, the point-like aggregate beam 1 shown in FIG.
By scanning 0, a large number of stripe-shaped scanning beams 16 as shown in FIG. 10 are formed.

In the present invention, the heating interference may be applied to the resin surface of the workpiece in accordance with a point-like or linear collective interference pattern, or in the case of performing irradiation by scanning, in accordance with the scanning pattern. A pattern can be formed. Generally, in a point-like or linear collective interference pattern, a molten portion or a relative concave portion of the resin is formed corresponding to the same phase portion, and a non-melted portion or a relative convex portion of the resin corresponding to the opposite phase portion. Is formed.

In the present invention, the molten resin layer may be in an amorphous or low crystallized state, or may be in a thermally crystallized state. A very limited part of the oriented crystallized resin from the surface to the middle in the thickness direction is rapidly heated to a temperature higher than the melting point within a short time, and rapidly cooled to a temperature lower than the crystallization temperature when the heating is stopped. By doing so, the molten resin layer is in an amorphous state or a low crystallized state. In the case of the amorphous portion or the low crystallization portion, the impact resistance of the processed portion is maintained at a high level. On the other hand, if the time during which the molten resin layer passes through the crystallization temperature region is long, the tendency of the molten resin layer to thermally crystallize increases. In a packaging container, thermal crystallization of the molten resin layer also occurs when the heat treatment temperature range of the container and the crystallization temperature range of the outer surface layer resin overlap as in the case of hot filling or retort sterilization. When the molten resin is thermally crystallized, it becomes somewhat brittle as a property, and provides an advantage that, for example, the tearability is improved.

For such limited rapid heating and rapid cooling, for example, scanning irradiation of a carbon dioxide gas laser beam can be used. In this case, by changing the output and scanning speed of the laser beam, the molten layer can be cooled. Thickness and temperature can be controlled.

In FIG. 11 showing an example of a heating pattern on the resin surface of the workpiece, A shows an example using a conventional laser beam, and the resin surface 30 of the workpiece has an unprocessed portion (unheated portion) 31. And a solid processed portion (molten resin portion) 32. On the other hand, B, B ′, and C show examples using the point-like or linear collective interference pattern of the present invention, and in B and B ′, a processed portion 32 is formed on the resin surface 30 of the workpiece. However, the processed portion 32 includes a striped heating portion (melted portion) 33 and an unheated portion (non-melted portion) 34.
And exist alternately. This striped processed part 3
2 may be linear or curved. In C, a processed portion 32 is formed on the resin surface 30 of the workpiece, and the processed portion 32 has an island shape in a continuous sea-like unheated portion (non-melted portion) 34. There are dispersed heating portions (melting portions) 33. The above-described structure or structure according to the present invention provides a great advantage in heating the resin surface.

For example, when a thermoplastic resin such as polyester, polyamide or olefin resin is stretched uniaxially or biaxially, its tensile strength, impact resistance, heat resistance, transparency and the like are improved, but its tear strength is also improved. As a result, it is difficult to open the packaging bag or the like by hand. When the resin having such molecular orientation is melted by heating, the molecular orientation disappears and the strength is weakened, so that tearing properties can be imparted, but at the same time, the toughness of the melt-processed portion tends to be significantly reduced. is there. On the other hand, when a molten pattern of a dot-like or linear resin is formed according to the present invention, the tearing property can be imparted without lowering the toughness of the processed portion.

Further, when an interference pattern processing is performed on a workpiece whose surface resin is uniaxially or biaxially oriented, a molten portion of the resin is formed corresponding to the same phase portion and corresponding to the opposite phase portion. In addition to the formation of the non-melted portion of the resin, the advantage is that the relative concave portion of the resin is formed corresponding to the same phase portion and the relative convex portion of the resin is formed corresponding to the opposite phase portion. is there.

In FIG. 12 showing this example, on the resin surface 30 of the workpiece, peaks 35, 35 which are larger than both outer contours of the point-like or linear collective interference pattern irradiating portion are formed. Molten portion of resin and relative recess 3 corresponding to the portion
6 are formed, and a non-melted portion of the resin and a relative convex portion 37 are formed corresponding to the opposite phase portion. In addition, the form of the unevenness changes depending on the pitch of the interference pattern. When the pitch is wide, as shown in the example of FIG. 13, a peak 35 protruding from the resin surface 30, an unmelted portion 34 of the same height, and a valley are formed. A state in which these are repeated, such as a concave portion, which is again a mountain 35, is formed.

In this surface structure, the tearing is easily performed at the relative concave portion 36, and the peak 35 is effectively prevented from shifting in the tearing direction. The formation of the relative concave portion and the relative convex portion is considered to be due to the fact that the resin is scattered, but the molecular orientation in the unmelted portion of the resin causes tension in the resin in the molten portion.

The formation of the resin melting pattern shown in FIG. 11 provides a remarkable advantage even when the surface of the workpiece is thermally crystallized. For example, when a thermoplastic resin such as polyester is thermally crystallized, its heat resistance, rigidity and the like are remarkably improved, but on the other hand, the melting temperature is increased, so that a cup,
There is a problem that heat sealing becomes difficult in a packaging container such as a tray. In the present invention, when a resin melting pattern as shown in FIG. 11 is applied to a heat-sealing flange portion of a packaging container such as a cup or a tray, an amorphous layer of resin is formed in the resin melting portion, and the resin is melted. Heat sealing is possible between the two, and the crystallized resin also exists in the processed portion in a sea-like or stripe-like shape, so that there is an advantage that excellent heat resistance is maintained.

Further, according to the processing method of the present invention, since the surface structure shown in FIG. 12 is formed in the interference pattern processing portion, formation of a non-slip portion of the processing material and prevention of blocking of the processing material such as a label. Formation, formation of a water-repellent part on the sliding surface of the workpiece such as skis and sleds, formation of a laminar flow-inducing part at the part in contact with the fluid of the workpiece, and improvement of the wear resistance of the workpiece It can also be used for forming, forming a temporary label-attached portion of the work material that is easily peelable, forming a decorative portion of the work material, forming an opaque portion of the work material, and the like.

The outer surface resin of the workpiece is JIS K
In the case of a thermoplastic resin having a moisture content of 0.1% by weight or more according to 0068, foaming of the resin due to moisture in the resin occurs as well as relaxation of orientation due to melting. FIG.
Shows a state in which a foam cell 38 is formed in the surface resin 30 of the workpiece, and the foam cell 38 may be a communicating cell type or a closed cell type. This foam structure may be a heat insulating part of the workpiece.

[0050]

The present invention will be described more specifically with reference to the following examples.

Example 1 15 μm biaxially stretched nylon-6 film and 130 μm
Was dry-laminated using a urethane-based adhesive. As shown in FIG. 1, the laser beam was converted into a point-like aggregate beam by a kaleidoscope through a planoconvex lens, and a weakened zone was processed on the nylon surface of the laminate at a speed of 13 m / min along the roll direction. In addition, the focal length of the plano convex lens is 2.5 inches, the length of the kaleidoscope is 138 mm,
The entrance of the cavity is a rectangle of 3 x 6 mm, and the exit is 6 x 6 mm
The distance between the exit surface of the kaleidoscope and the laminate was adjusted to 8 mm. Further, the laser output was changed from 160 W to 220 W every 20 W. The surface state of the laminate thus obtained was observed with a scanning electron microscope. The entire width of the weakened zone under any of the conditions is about 6 mm, and the molten weakened line portion having a width of about 150 μm and the width of about 150 mm are also used.
μm unmelted lines were alternately present. When the cross section was observed, the central portion of each melt-weakening line portion of the nylon layer was slightly thinner than the original thickness, and the end portions were in a raised state. In addition, in the case of 200 W and 220 W, foaming was observed in a part of the melt weakening line portion of the nylon layer, but did not penetrate. A doypack-type standing pouch was prepared using the two-layer laminate, filled with a liquid detergent, and sealed. In addition, the laser processing part was located at the same position on the front and back of the pouch, respectively, in a position parallel to the heat seal part on the filling port side of the pouch and slightly shifted downward. With respect to these pouches, a drop test was performed five times at 5 ° C. in two ways from a height of 80 cm in an upright state and a sideways state. Under all conditions, none of the pouches were broken as raw pouches. In addition, when the film was torn from the laser-processed portion, all were torn linearly along the weakened zone, and the tearability was good. The tearing property was better as the laser output was larger, but this is probably due to the promotion of relaxation of the molecular orientation of the nylon layer or the foaming. Also, although the torn portion is visually linear, when observed with a scanning electron microscope, it is mainly torn along one melt-weakening line, and the tear is displaced in the middle and the adjacent melt-weakened line is Some parts have moved. As described above, the straight-line tearing property was stably maintained by arranging a plurality of melt weakening lines in parallel at minute intervals. In addition, the nylon film layer of this laminated body was peeled off, and the water content measured by a method specified by JIS K 0068 was 1.5% by weight.

COMPARATIVE EXAMPLE 1 As shown in FIG. 2, a carbon dioxide laser beam was condensed by a planoconvex lens (focal length: 2.5 inches), and the velocity was applied to the nylon surface of the laminate used in Example 1 in the roll direction of the laminate. The line of weakening was processed at 13 m / min. At this time, adjustment was performed so that the distance between the lens and the laminated body coincided with the focal length. Further, the laser output was changed every 5 W from 5 W to 25 W. The surface state of the laminate thus obtained was observed with a scanning electron microscope. Under the condition of 5 W, the remaining thickness of the nylon layer in the concave portion formed by the laser processing was about 80% of the original thickness in a thin portion, and almost no weakened line was formed. Further, under the condition of 15 W or more, the width of the weakened line was 1 mm or less, and the outer nylon layer completely disappeared and was broken. The condition of 10 W is an intermediate state between the conditions of 5 W and 15 W. In some cases, as in 5 W, the formation of the weakening line is insufficient, and in some cases, 1 W
The film broke like 5 W, and the remaining portion had a slight remaining nylon layer. Using this two-layer laminate, a standing pouch was prepared in the same manner as in Example 1, filled with a liquid detergent, and sealed. In addition, it was considerably difficult to position the laser-processed portion at the same position on the front and back of the pouch, as compared with Example 1, because the width of the processed portion was narrow. When a drop test was performed in the same manner as in Example 1, the bag did not break under the conditions of 5 W and 10 W, but did break considerably at 15 W or more. Further, when tearing was performed from the laser-processed portion, the tear was significantly shifted from the processed portion under the conditions of 5 W and 10 W. Under conditions of 15 W or more, if the film was torn with caution, it was torn linearly along the line of weakness, but rarely fell apart from the line of weakness. For each of the laminates produced in Example 1 and Comparative Example 1, a strip having a width of 15 mm was cut out perpendicularly to the laser-processed portion, and placed at the center of the portion where the laser-processed portion was extended, and a tensile test was performed. The initial sample length of the part to be stretched is 20 mm,
The tensile speed was 50 mm / min. Table 1 shows the results.
An example of a measurement chart is shown by a curve a (Example) and a curve b (Comparative Example) in FIG.

[0053]

[Table 1] As shown in Table 1, Example 1 showed a slightly higher value in yield point strength and a value about three times larger in yield point strain than Comparative Example 1. This is because, in the comparative example, stress was concentrated on only one melt-weakened line portion and locally deformed irrespective of the depth of the laser processed portion, whereas in the example, the stress was applied on many melt-weakened line portions. This is due to dispersion and large deformation in the form of bellows.

Example 2 12 μm biaxially oriented polyethylene terephthalate film (PET), 7 μm soft aluminum foil, and
Each interface of 0 μm linear low density polyethylene,
Low density polyethylene was extruded to a thickness of 15 μm and sandwich laminated. Using the laminated body composed of the five layers, the edge heat seal portion of the three-way heat seal pouch was subjected to laser processing to form a weakened portion for starting opening. In addition,
Two processing locations were provided on the PET surface of the outer layer so as to be located at the same position on the front and back of the pouch. Laser processing was performed using a carbon dioxide laser beam as a point-like aggregate beam using a kaleidoscope through a planoconvex, with a laser output of 60 W and an irradiation time of about 60 msec. The focal length of the planoconvex lens was 2.5 inches, and the same kaleidoscope as in Example 1 was used. Also,
The distance between the exit surface of the kaleidoscope and the laminate was adjusted to 8 mm. The pouch thus prepared has a large number of dot-shaped weakened portions, a pitch of about 0.3 mm, a length of 6 mm on the edge of the heat-sealed portion, and a width of 3 mm on the edge.
Was scattered in the range. Cut out the section from this part,
When observed with a polarizing microscope, the outer PET layer was melted by the laser processing in the weakened portion, and the orientation was relaxed or lost. Further, this pouch, in which foaming was observed in a part of the melted portion, could be easily torn from the weakened portion without the notch. In addition, the PET film layer of this laminate was peeled off, and the water content measured by the method specified in JIS K 0068 was 0.1% by weight. In addition, the laminate obtained by adjusting the laminate using a vacuum dryer for 2 days does not foam even if it is laser-processed under the same conditions as in Example 2.
The onset of tearing was slightly inferior to Example 2.
The PET film layer of the laminate was peeled off and J
The water content as measured by the method specified by IS K0068 was 0.05% by weight.

Comparative Example 2 A pouch not subjected to laser processing in Example 2
No tearing was possible from the edge heat seal.

Example 3 Using the same laminate and optical system as in Example 2, a laser beam was scanned to form a weakened band for opening on the three-way heat seal pouch 50. In addition, as shown in FIG.
The scanning was performed at a scanning speed of 13 m / min on the belt in a direction perpendicular to 1a toward the edge heat seal portion 51b. The laser-processed part of the pouch thus created has a width of about 150 μm.
And an unmelted line portion having a width of about 150 μm alternately existed in a stripe shape with a width of 6 mm. In this pouch, there was nothing that filled the contents with a liquid soup or the like and broke the bag from the laser processing part in a transport test or the like. In addition, even if there is no notch, it is easy from the end of the laser processing part, and
The pouch was torn linearly along the processed part, and the pouch could be divided into two parts.

Comparative Example 3 A pouch not subjected to laser processing in Example 3
It was torn from the opening notch cut in the edge heat-sealed portion, but the tear again became torn and could not be completely torn.

Example 4 Using the same laminate and optical system as in Example 2, at the connecting portion of the pouch in which a plurality of three-way heat sealing pouches were connected at the edge sealing portions, Processing was performed by scanning with a laser beam under the same conditions as in Example 3 in parallel with the edge sealing portion. Pouches made of a plurality of pieces created in this way, even if the perforations are not cut in the connection part,
The connecting portion was easily torn from the end of the laser-processed portion and linearly torn along the processed portion, and could be divided into individual pouches.

Comparative Example 4 When laser processing was not performed in Example 4, the connecting portion could not be torn. Further, when a notch for starting the tearing was provided at the end of the connecting portion, the tearing was shifted to the sealed portion side of the bag, and the bag was torn again, so that the bag could not be completely torn.

Example 5 The center of a cylindrical biaxially stretched bottle made of polyethylene terephthalate having a full capacity of about 1 liter was subjected to laser processing using the same optical system as in Example 2, and the bottle surface was slid. Stop processing was performed. In the laser processing, as shown in FIG. 3, a carbon dioxide laser beam is converted into a point-like aggregate beam with a kaleidoscope through a planoconvex, and a laser output 18 is obtained.
The operation was performed by rotating the bottle at 0 W and a linear velocity of 18 m / min on the surface of the bottle. The distance between the exit surface of the kaleidoscope and the surface of the bottle was adjusted to 8 mm. As shown in the cross-sectional view of FIG. 16, the laser processing portion on the bottle side wall thus formed has a pitch of about 260 μm and a height difference of about 80 μm.
m was formed in a striped shape around the bottle. It is considered that the unevenness on the bottle surface occurred when the polyethylene terephthalate resin was melted and the orientation was relaxed. When the bottle was filled with 1 liter of water and lifted by hand, the processed portion was less slippery with respect to the unprocessed portion, exhibiting an anti-slip effect.

Example 6 As in Example 5, the side wall of the bottle was subjected to laser processing. However, laser processing is 2cm while rotating the bottle
It went up and down with the width of. On the side wall of the bottle thus produced, a laser processing trace having the same irregularities as in Example 5 was formed in a wavy pattern. The unevenness was slightly different depending on the location of the wave pattern. It is considered that this is because the direction of the kaleidoscope and the processing direction are shifted from place to place.

Example 7 and Comparative Example 5 A sheet made of polyethylene terephthalate containing a crystal nucleating agent was thermoformed at about 150 ° C. to have a flat heat-sealing flange having a width of about 7 mm.
A round cup container having an outer diameter of 80 mm and a full capacity of about 80 cc was prepared. The density (crystallinity) of the flange portion of this container was about 1.377 g / cc (about 34%).
Next, the flange surface of this container was surface-modified using a carbon dioxide laser beam. For laser processing, the same optical system as in Example 1 was used, and the cup was rotated to obtain an output of 200 W,
At a linear velocity of 20 m / min, at the center of the heat seal flange,
At one time, it was applied for one round of the flange. The distance between the exit surface of the kaleidoscope and the surface of the cup was adjusted to 8 mm. A section was cut out from the flange portion of the cup, and the laser-processed portion was observed with a polarizing microscope. As a result, parts other than the processed part are crystallized during cup molding,
While the whole is cloudy, the processed part has a width of about 150μ.
m transparent portions were also present alternately with white turbid portions having a width of about 150 μm in a striped fashion with a width of 6 mm. It is considered that the transparent portion is made amorphous by melting and quenching the polyethylene terephthalate resin. Also, as a lid material,
12 μm biaxially stretched polyethylene terephthalate film, 15 μm biaxially stretched nylon film,
A 0 μm aluminum foil and a polyester sealant film were dry-laminated using a urethane adhesive. In addition, two types of sealants, a 30 μm sealer PT (manufactured by Mitsui DuPont Chemical Co., Ltd., and a lid using the same), and a 50 μm YT-11C (Tokyo Sero Chemical Co., Ltd., using this as a lid B) Was evaluated. These lids were heat-sealed by filling 65 cc of water in each of the laser-processed product and the unprocessed product of the above-mentioned container, and heat-sealing strength was measured and a transport test was performed using a vibration tester. The heat sealing conditions were a heat seal width of 5 mm, a heat seal time of 1.5 seconds, and a heat seal temperature of 180 ° C to 2 ° C.
40 ° C. In addition, the heat sealing strength was determined by cutting a 15 mm wide strip in a direction perpendicular to the heat sealing section with the lid attached to the cup, fixing the cup horizontally, and moving the end of the strip upward at a speed of 300 mm / min. It was measured by pulling.
A tensile tester was used for the measurement. Since the heat seal strength was high in the melted portion of the laser processing and low in the non-melted portion, the maximum value was read and evaluated. Table 2 shows the evaluation results.

[0063]

[Table 2] As shown in Table 2, when laser processing was performed, 18
At a heat sealing temperature of 0 ° C. or higher, a heat sealing strength of approximately 1 kgf was exhibited. In any of the conditions, no heat-sealed portion was damaged in the transport test. When the container was opened by hand, the lid could be easily peeled off even when the container was heat-sealed at 240 ° C., which showed the highest heat-sealing strength. This is because the heat sealing strength is high in the melted portion of the laser processing, but low in the non-melted portion, so that the peeling force required for unsealing is the average strength of these. On the other hand, in the case of unprocessed products, 0.5 kgf
Shows the heat seal strength. A transport test under these conditions revealed that nearly half of the devices were broken from the heat-sealed portion and the contents leaked. Then, the heat sealing temperature was further increased to 250 ° C., but in this case, the outer surface film of the lid was melted and began to adhere to the heat sealing head, so that the heat sealing could not be performed.

Example 8 As a foaming resin, 65 parts by weight of a polypropylene random copolymer having an ethylene content of 4% by weight and 35 parts by weight of a linear low-density polyethylene were dry-blended, and 3 parts by weight of carbon black and foam 10 parts by weight of azodicarbonamide as an agent, 2 parts by weight of trimethylolpropane trimethacrylate as a crosslinking aid, and BHT as an antioxidant
One part by weight was mixed using a twin-screw extruder at a temperature not higher than the decomposition temperature of the foaming agent, and a non-foamed sheet having a thickness of 0.2 mm was formed using a T-die. The unfoamed sheet was irradiated with an electron beam to crosslink, and then a 0.8 mm thick polypropylene sheet was extruded to obtain a 1 mm thick sheet. This sheet was thermoformed to prepare a cup container similar to that in Example 7. Next, the side wall of the container was irradiated with a carbon dioxide gas laser beam to foam the container. For laser processing, the same optical system as in Example 1 was used, and the cup was rotated to obtain an output of 200.
W, 1m at 2 places near the center of the side wall at a linear velocity of 13m / min
It was provided at intervals of about m. The distance between the exit surface of the kaleidoscope and the surface of the cup was adjusted to 8 mm. When the thickness of the side wall portion of this cup was measured, the unprocessed portion was approximately 0.5 mm and the laser processed portion was foamed to a thickness of approximately 3 mm, depending on the location. When boiling water was put into this cup and it was held by hand, the unprocessed portion was hot and could not be held, but the foamed portion could be held as a heat insulating layer.

Example 9 The same cup as in Example 7 was molded by injection using polyethylene terephthalate. The side wall of this cup was laser-processed under the same conditions as in Example 7. However, the laser processing was performed until the processed part thermally crystallized and became white with the cup stopped. The obtained cup had an opaque laser-processed portion.

Example 10 and Comparative Example 6 75 having a 15 μm epoxy phenol coating on both sides
A μm steel foil was prepared. Using this metal foil and a urethane-based elastic punch, a cup container having the same form as in Example 7 was formed from this foil. Laser processing was performed on the edge portion at the bottom of the cup container. Note that laser processing was performed several times under the same conditions as in Example 8. However, the inclination of the kaleidoscope was adjusted so that the interference pattern was relatively flat. The pencil hardness at the bottom edge of the cup container was 4H for the laser-processed product and H for the unprocessed product. The cup was filled with clay instead of the contents, and placed on a vibration tester to examine the scratch resistance. As a result, the edge portion which was most easily damaged was less in the laser-processed product than in the unprocessed product. In the case where the baking conditions were increased and the pencil hardness of the coating film was adjusted to 4H from the beginning, there was a case where the coating film was peeled off at the side wall portion during cup molding.

[0067]

According to the present invention, a laser beam is incident on a tubular interference optical system to form a point-like or linear collective interference pattern, and this point-like or linear collective interference pattern is formed on the surface of a workpiece. By irradiating the laser beam, the laser beam is divided into a number of peaks in the width direction, and the height of each peak is also suppressed to a uniformly low height. This is an extremely great advantage for processing a workpiece whose surface is made of resin. Is brought. That is, it is possible to prevent the resin from being locally heated to a high temperature, to prevent the generation of fumes, to prevent the resin from being thermally decomposed or deteriorated, and to perform a large-area processing on the workpiece. Moreover,
According to the present invention, substantially all of the energy of the laser beam can be used for processing the resin, and there is an advantage that there is no energy loss unlike the case of using a pattern mask.

In the interference pattern with respect to the resin, generally, of the point-like or linear collective interference pattern, a molten portion or a relative concave portion of the resin is formed corresponding to the same phase portion, and corresponding to the opposite phase portion. As a result, a non-melted portion or a relative convex portion of the resin is formed, and an extremely unique structure or structure can be formed on the surface of the workpiece. By forming such an interference pattern on the resin surface, it is possible to effectively suppress a decrease in toughness of the processed resin.

The present invention can be widely applied to interference pattern processing of a work material having at least a surface made of a resin, and this interference pattern processing is, for example, easily broken such as a score portion or a tear start portion of the work material. Formation of heat-resistant part, formation of heat-sealed part of work material, formation of non-slip part of work material, formation of anti-blocking part of work material such as label, sliding surface of work material such as skis and sledges Formation of a water-repellent portion, formation of a laminar flow-inducing portion at a portion in contact with a fluid of a work material, formation of a wear resistance improving portion of a work material, temporary label sticking portion of a work material with easy peelability , A decorative portion of the workpiece, an opaque portion of the workpiece, a foamed heat insulating portion, and the like.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a principle of generating an interference pattern by a tubular interference optical system.

FIG. 2 is an explanatory view showing a conventional laser beam irradiation method.

FIG. 3 is a graph showing an energy distribution of a laser beam in FIG.

FIG. 4 is an explanatory diagram for explaining a point-like aggregate beam when a kaleidoscope having a square entrance and an exit is used.

FIG. 5 is an explanatory diagram for explaining a linear aggregate beam when a kaleidoscope having a circular entrance and an exit is used.

FIG. 6 is an explanatory diagram for explaining a point-like aggregate beam when a kaleidoscope having a triangular entrance and an exit is used.

FIG. 7 is an explanatory diagram for explaining a point-like aggregate beam when a kaleidoscope having a hexagonal entrance and an exit is used.

FIG. 8 is an explanatory diagram showing a dimensional relationship between an inlet and an outlet of a kaleidoscope and a linear beam formed.

FIG. 9 is an explanatory diagram showing a relationship between an aspect in which a kaleidoscope is displaced from an optical axis and a point-like aggregate beam formed by the arrangement.

FIG. 10 is an explanatory diagram showing a linear beam when scanning is performed using the kaleidoscope of FIG. 1;

FIG. 11 is an explanatory view showing a surface state of an interference pattern processed portion of a workpiece surface resin, where A is an example in which the processed portion is formed of a solid melt-weakened resin layer, and B and B ′ are processed portions. Indicates an example in which a plurality of stripe-shaped melt-weakened resin layers are formed, and C indicates an example in which a processed portion is formed of a large number of dot-shaped melt-weakened resin layers.

FIG. 12 is an explanatory diagram showing a state in which an interference pattern processing portion is composed of a relative concave portion and a relative convex portion.

FIG. 13 is an explanatory diagram showing a state different from the state shown in FIG. 12;

FIG. 14 is an explanatory diagram showing a state in which the interference pattern processing portion is made of a foam.

FIG. 15 is a load-strain curve illustrating the effect of the present invention.

FIG. 16 is a cross-sectional view of a bottle side wall portion laser-processed using a kaleidoscope.

FIG. 17 is an external view of a three-way seal pouch according to a third embodiment.

Claims (21)

[Claims] 1. A point-like or linear collective interference pattern obtained by irradiating a laser beam into a tubular interference optical system is irradiated onto a surface of a work material having at least a surface made of resin, and an interference pattern is formed on the resin surface. A method for processing a resin surface, comprising processing. 2. A point-like or linear collective interference pattern,
2. The resin according to claim 1, wherein a molten portion or a relative concave portion of the resin is formed corresponding to the same phase portion, and a non-melted portion or a relative convex portion of the resin is formed corresponding to the opposite phase portion. Processing method. 3. The processing method according to claim 1, wherein a pitch between points or lines of the point-like or linear collective interference pattern is in a range of 0.02 to 5 mm. 4. The processing method according to claim 1, wherein the point-like or linear collective interference pattern has a dimension of 1 mm or more in at least one direction. 5. The processing method according to claim 1, wherein the point-like or linear collective interference pattern has an incident energy corresponding to 3 to 40 J per unit area (1 cm ² ). 6. The processing method according to claim 1, wherein the tubular interference optical system has a polygonal, circular or elliptical cross-sectional shape. 7. The processing method according to claim 1, wherein the interference pattern processing is performed while the point-like or linear collective interference pattern and the workpiece are relatively stationary. 8. The processing method according to claim 1, wherein the interference pattern processing is performed by relatively scanning the point or linear collective interference pattern and the workpiece. 9. The processing method according to claim 1, wherein at least the surface of the workpiece is formed of a thermoplastic resin. 10. The processing method according to claim 9, wherein the thermoplastic resin is an olefin resin, a polyester resin, a polyamide resin, a styrene resin, or a vinyl chloride resin. 11. The processing method according to claim 9, wherein the thermoplastic resin is a crystallized or molecularly oriented thermoplastic resin. 12. The processing method according to claim 9, wherein the workpiece is a film, a sheet, a resin laminate, or a molded body. 13. The processing method according to claim 1, wherein at least the surface of the workpiece is formed of a thermosetting resin. 14. The processing method according to claim 13, wherein the workpiece is a painted body or a molded body. 15. The processing method according to claim 1, wherein the interference pattern processing portion is an easily breakable portion of the workpiece. 16. The processing method according to claim 1, wherein the interference pattern processing part is a heat seal part of a workpiece. 17. The processing method according to claim 1, wherein the interference pattern processing portion is a non-slip portion of the workpiece. 18. The processing method according to claim 1, wherein the interference pattern processing portion is a temporary label sticking portion on which the workpiece is easily peelable. 19. The processing method according to claim 1, wherein the interference pattern processing part is a decorative part of the workpiece. 20. The processing method according to claim 1, wherein the interference pattern processing portion is an opaque portion of the workpiece. 21. The processing method according to claim 1, wherein at least the resin on the surface is a resin containing moisture, and the interference pattern processed portion is a foamed heat insulating portion.