JPH0156907B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin laminate that can be sharply cut with a laser beam.

Generally, when cutting a synthetic resin laminate using a laser beam, if the synthetic resin laminate is made of thermosetting synthetic resin, the thickness of the synthetic resin laminate is 2 mm.
In the following cases, a sharp cut surface is formed and it is easily cut, but as the thickness increases, the synthetic resin causes a melting phenomenon, making it difficult to cut sharply, and the cut surface becomes uneven. In addition, if it is made of thermoplastic synthetic resin, the synthetic resin melts and flows, making the cut surface uneven, and the longer the cutting length, the wider the cutting width becomes In this method, the cutting width expands from the laser beam projection surface to the back surface, making vertical cutting difficult. It was difficult to make it form.

This invention was made for the purpose of obtaining a synthetic resin laminate that can be cut sharply with a laser beam even if it is thick, and as a result of various studies, it has a thickness of 2 mm or less, A thermosetting synthetic resin-impregnated base sheet layer with a synthetic resin content of 5 to 35% by weight, and a synthetic resin having a thickness that is equal to or 10 times or less than the thermosetting synthetic resin-impregnated base sheet layer. A laminate is formed by laminating alternately thermoplastic synthetic resin-impregnated base sheet layers with a content of 5 to 35% by weight, with the outermost front and back surfaces being thermosetting synthetic resin-impregnated base sheet layers. It was confirmed that the object of the present invention could be achieved.

The synthetic resin used in the present invention is a common synthetic resin used for manufacturing laminates,
The thermosetting synthetic resin-impregnated base sheet layer is obtained by impregnating a thermosetting resin such as phenolic resin, polyester resin, or melamine resin into a base sheet made of kraft pulp or kraft paper using a conventional method and drying it to obtain a synthetic resin content. is prepared in a so-called prepreg state containing 5 to 35% by weight, and the thermoplastic synthetic resin impregnated base sheet layer is prepared using a thermoplastic resin solution or emulsion such as acrylic resin, vinyl acetate resin, acrylonitrile styrene butadiene rubber, or polyamide resin. A sheet having a synthetic resin content of 5 to 35% by weight is prepared by impregnating or coating the same base sheet as above and drying it by a conventional method.

Next, these synthetic resin-impregnated base sheet layers are stacked alternately so that a thermosetting synthetic resin-impregnated base sheet layer is formed on both the outermost front and back surfaces, and then heat-cured and press-cured by a conventional method to obtain an overall thickness. is formed into a laminate plate with a thickness of 2 mm or more.

When the thus obtained laminate of the present invention is irradiated with a laser beam, it is cut with extremely sharp cuts, but at this time, the thickness of the laminate is optimally 30 mm or less, particularly 20 mm or less, and the entire laminate is cut. thickness is 30
If the diameter exceeds mm, it is difficult to obtain a sharp cross section using a laser beam. Further, the type of laser beam used does not matter as long as it has a high output, but a high-output carbon dioxide laser is most suitable from the viewpoint of handling, and for example, a carbon dioxide laser with a wavelength of 10.6 μm and an output of 425 W is used.

In the present invention, the synthetic resin content is 5 to 35% by weight.
The reason for this stipulation is that when the synthetic resin content is less than 5% by weight, the amount of resin relative to the base sheet is small, and therefore sufficient adhesive bonding between the base sheets cannot be obtained, causing delamination and lamination. This is because it cannot withstand use as a plate, and when it exceeds 35% by weight, when cutting with a laser beam, unevenness due to melting and flow of the resin will be observed on the cut surface, making it impossible to obtain a sharp cut surface. In addition, various combinations of the thermosetting resin-impregnated base sheet layer and the thermoplastic resin-impregnated base sheet layer are possible, but the optimal combination that allows a sharp cross section to be obtained with a laser beam is the thermosetting resin-impregnated base sheet layer. This is a case in which the sheet layers and the thermoplastic resin-impregnated base sheet layers are alternately formed to have the same thickness, and the thermosetting resin-impregnated base sheet layers are formed on both the outermost front and back surfaces.

The thickness of the thermosetting resin-impregnated base sheet layer is 2 mm or less, the thickness of the thermoplastic resin-impregnated base sheet layer is equal to or 10 times or less than the thickness of the thermosetting resin-impregnated base sheet layer, In order to form a laminate with an overall thickness of more than 2 mm, the synthetic resin content was 5 mm.
It has already been experimentally determined how many synthetic resin-impregnated base sheet layers consisting of ~35% by weight of kraft pulp and kraft paper should be combined and molded.
It is well known from experience that generally 20
When molded with a press pressure of ~70Kg/ ^cm2 , in the case of a synthetic resin-impregnated base sheet layer made of kraft pulp or kraft paper with a synthetic resin content of 5 to 35% by weight, the thickness after pressing will be the same as the thickness before pressing. 90-50% of
Therefore, if the pressing pressure is 70 kg/cm ² , the thickness of the molded product will be approximately 1/2 of the thickness before pressing.

The present invention will be illustrated below with examples, but the thermosetting synthetic resins and thermoplastic synthetic resins used are not limited to those shown in the examples, and any synthetic resins that are compatible with each other may be used. Furthermore, the combination of the thermosetting resin-impregnated base sheet layer and the thermoplastic resin-impregnated base sheet layer is also limited to those shown in the examples as long as it falls within the limited scope of the present invention. Of course not.

Example 1 A composition consisting of 1.0 mol of phenol, 1.2 mol of formaldehyde, 0.04 mol of NH ₄ OH, and 0.01 mol of NaOH was reacted at 95°C for 90 minutes, dehydrated and diluted with methanol to give a viscosity of 30 CPS (30°C) solid content. A 60% by weight methanol-soluble phenolic resin varnish was obtained.

Next, unbleached kraft pulp with a thickness of 0.3 mm and a basis weight of 150 g/m ² is impregnated with the phenolic resin varnish.
The mixture was squeezed and dried to obtain a phenolic resin-impregnated prepreg sheet with a resin adhesion amount of 18% by weight. On the other hand, unbleached kraft paper with a thickness of 0.3mm and a basis weight of 150g/ ^m2 has a solid content of 4.545.
% by weight of styrene-butadiene rubber latex, squeezed and dried to obtain a thermoplastic synthetic resin-impregnated base sheet with a resin adhesion of 21% by weight.

Next, the 10 phenolic resin-impregnated prepreg sheets and the 9 thermoplastic synthetic resin-impregnated base sheets were alternately stacked one by one and pressed together so that the phenolic resin-impregnated prepreg sheets constituted the outermost front and back layers. Pressure molding was carried out at 60 kg/cm ² at a temperature of 150° C. for 70 minutes of heating time and 30 minutes of cooling time to obtain a synthetic resin laminate with a product thickness of 3.7 mm.

When this laminate was irradiated with a carbon dioxide laser with a wavelength of 10.6 μmm and an output of 425 W and cut into two laminates, the cross section was extremely smooth and sharp.

Example 2 27 phenolic resin-impregnated prepreg sheets obtained in Example 1 and 24 thermoplastic synthetic resin-impregnated base sheets obtained in Example 1 were combined, with the phenolic resin-impregnated prepreg sheet being the outermost front and back surfaces. Alternately stack three sheets at a time to form a press pressure of 30
Kg/ ^cm2 , temperature 150℃, heating time 70 minutes, cooling time 40 minutes
A laminate with a thickness of 11.5 mm was obtained by pressure molding in minutes.

When this laminate was irradiated with a laser beam under the same conditions as in Example 1 and the center of the laminate was cut into a circular shape, a laminate with a circular hole and a disc that fit into the hole were obtained. Both cross sections were smooth and sharp as in Example 1.

Example 3 Consisting of 65% by weight of polyester resin (trade name Rigorac #2600, manufactured by Showa Kobunshi Co., Ltd.), 30% by weight of diallyl phthalate prepolymer (trade name: DAP Prepolymer, manufactured by Osaka Soda Co., Ltd.), and 5% by weight of diallyl phthalate monomer. The composition is acetone:toluene=2:1
Then, 1.5% by weight of tert-butylperoxyisopropyl carbonate was added as a catalyst to 100 parts by weight of solid content and stirred to obtain a diallylphthalate-modified polyester with a viscosity of 40 CPS (30°C) and a solid content of 65%. A resin varnish was obtained.

Next, an unbleached kraft pulp having a thickness of 0.3 mm and a basis weight of 150 g/m ² was impregnated with the polyester resin varnish and squeezed and dried to obtain a polyester resin-impregnated prepreg sheet with a resin adhesion amount of 30% by weight.

The 10 thus obtained prepreg sheets and the 8 thermoplastic synthetic resin-impregnated base material sheets obtained in Example 1 were combined into two sheets each, with the polyester resin-impregnated prepreg sheets constituting the outermost front and back double-sided layers. Alternately stacked, press pressure 30Kg/cm ² , temperature 150
Pressure molded at ℃, heating time 50 minutes, cooling time 30 minutes,
A laminate with a thickness of 4.8 mm was obtained.

When this laminate was cut with a laser beam under the same conditions as in Example 1, a smooth and sharp cut surface was obtained.

Example 4 Five polyester resin-impregnated prepreg sheets obtained in Example 3, thickness 1.8 mm, basis weight 900 g/m ²
unbleached kraft pulp was impregnated with styrene-butadiene rubber latex having a solid content of 45% by weight in the same manner as in Example 1, squeezed and dried to obtain a thermoplastic synthetic resin-impregnated base sheet 4 with a resin adhesion of 15% by weight. with a sheet,
Polyester resin-impregnated prepreg sheets were stacked one by one alternately to form the outermost front and back layers, press pressure 20 kg/cm ² , temperature 150°C, heating time 60
Pressure molding was performed with a cooling time of 30 minutes to obtain a laminate with a thickness of 8.1 mm. When the obtained laminate was cut in a fine curve with a laser beam, a section with an extremely sharp curve and a smooth cross section was obtained, which could be used as is as a jigsaw puzzle.

Example 5 Ten polyester resin-impregnated prepreg sheets obtained in Example 3, thickness 0.3 mm, basis weight 150 g/m ²
Nine thermoplastic synthetic resin-impregnated base sheets with a resin adhesion of 29% by weight, obtained by coating and drying vinylidene chloride latex with a solid content of 47% on unbleached kraft paper, were coated with polyester resin-impregnated prepreg sheets. Lay them one by one alternately to form the outermost front and back layers, press pressure 20Kg/cm ² , temperature 140℃,
Pressure molding was performed under conditions of heating time of 60 minutes and cooling time of 30 minutes to obtain a laminate with a thickness of 4.7 mm.

When this laminate was irradiated with a laser beam and cut into a gear shape, a sharp and smooth cut surface was obtained that could be used as a gear without any finishing work after cutting.

Comparative Example Ten phenolic resin-impregnated prepreg sheets obtained in Example 1 were stacked together at a press pressure of 70 kg/
cm ² , a temperature of 150° C., a heating time of 40 minutes, and a cooling time of 20 minutes to obtain a laminate with a thickness of 1.5 mm. When this laminate was irradiated with a laser beam under the same conditions as in the previous examples and the laminate was cut, a sharp and smooth cross section was obtained. In the laminate, the resin at the cut surface caused by the laser beam melted and became keloid-like, making it impossible to obtain a sharp cross section.

In addition, we attempted to cut a laminate consisting only of a base sheet layer impregnated with thermoplastic synthetic resin using a laser beam, but the thermoplastic resin thermally decomposed relatively easily, causing expansion and fusion of the cut portion. It was impossible to obtain a sharp cross section.

As explained in the detailed examples above, even if the laminate having the structure of the present invention is thicker than 2 mm, it can be cut extremely sharply and smoothly by laser beam irradiation. However, it was possible to freely and stably cut objects with fine curved shapes that cannot be cut using a jigsaw or the like.

Claims (1)

[Claims] 1 It has a thickness of 2 mm or less and has a synthetic resin content of 5
A base sheet layer impregnated with a thermosetting synthetic resin of ~35% by weight, having a thickness equal to or less than 10 times that of the base sheet layer impregnated with a thermosetting synthetic resin, and having a synthetic resin content of 5 to 35% by weight. % by weight of thermoplastic synthetic resin-impregnated base sheet layers are stacked alternately so that the outermost front and back surfaces are thermosetting synthetic resin-impregnated base sheet layers, and sharp cutting can be performed using a laser beam. Possible synthetic resin laminate.