JPH06206231A - Method for producing scratch-resistant transparent member - Google Patents

Abstract

(57) [Summary] [Structure] A transparent film coated with a surface-hardening layer of a siloxane-based or polyfunctional acrylate-based scratch-resistant surface-hardening agent is placed between the male and female molds, and mold closing is started. Then, the mold closing is temporarily stopped or the mold closing speed is set to 3
In a state of 0 mm / sec or less, a thermoplastic transparent resin is supplied between the transparent film and the male or female mold when the clearance between the male mold and the female mold is (C + 7) mm to (C + 0.1) mm, Then, a method for producing a scratch-resistant transparent member, in which the mold is closed and shaping is performed. [Effect] During the laminating composite form, the transparent film is not thermally deformed, and the scratch-resistant transparent member can be efficiently manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a scratch-resistant transparent member.

[0002]

2. Description of the Related Art Acrylic resin, polycarbonate resin,
Compared with glass, transparent resins such as polystyrene resin, AS resin, ABS resin, polyvinyl chloride resin, polyester resin, and acetate resin are lighter and have superior impact strength, so glazing, partitions, skydomes, sunroofs, carports , Side plates, doors, building materials such as sizing materials, optical applications such as optical disks, lenses, glasses, vehicle window glass, headlamps, lenses and lamp covers, vehicle applications such as rear panels, pillars and meter covers, AV equipment nameplates And widely used as various transparent members such as electric parts such as covers, covers for CRT devices, covers for luminaires, covers for vending machines, industrial parts, display boards, interiors, decorations such as displays, and miscellaneous goods. Is used by shaping it into the desired shape by injection molding, vacuum molding, etc. There are many.

However, in the case of the injection molding method, it is not suitable for processing a large-area product because the apparatus requires a large size because the mold clamping pressure needs to be increased, and in the case of the vacuum molding. Has a problem that a product with a complicated shape is difficult, and it is necessary to trim after vacuum forming, which causes a cost increase due to trimming loss.

Further, since the transparent member obtained by such a molding method has a poor wear resistance on its surface, there is a problem that the appearance is impaired by the effects of contact, impact, scratching and the like during use. After molding, a surface-hardened layer is provided to improve the scratch resistance, but this method increases the number of steps and causes a cost increase.

As a method for solving such a problem, for example, JP-A-60-210432 and JP-A-6-20632 are available.
No. 1-5943, etc., a method of laminating a curing agent-coated sheet or film on a transparent resin by injecting the transparent resin into a mold equipped with a polycarbonate film or sheet coated with a curing agent in advance. Are known.

[0006] However, in the case of such a method, although the scratch resistance of the molded article is improved, the injection pressure is high, so that there is a problem that the polycarbonate film serving as the skin layer is thermally deformed during the laminating and synthesis. is there.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The present inventors can easily manufacture even a complicated shape or a large-area product with a relatively low mold closing pressure, and further, without causing thermal deformation or the like, a transparent film obtained by laminating a transparent film having excellent scratch resistance. As a result of studies for manufacturing a member, the present invention has been completed.

[0008]

That is, the present invention is as follows.
(A) A first step of disposing a transparent film (3) coated with a surface-hardened layer between the male mold (2) and the female mold (1), (b) the male mold (2) and the female mold (1) Mold closing is started and the mold closing operation is stopped halfway or the mold closing speed is set to 30 m.
Male (2) and female (1) with m / sec or less
Cavity clearance (a) is (C + 0.1) m
The second step of supplying the thermoplastic transparent molten resin (4) between the transparent film (3) and the male mold (2) or the female mold (1) when m to (C + 7) mm (however, C
Is a cavity clearance upon completion of shaping, and (c) a third step of shaping by closing the male die (2) and the female die (1) until the cavity clearance (C) is reached. And a method for producing a scratch-resistant transparent member.

The method of the present invention will be described below with reference to the drawings.

1 to 4 are vertical sectional views of an example of an apparatus showing a method of the present invention. Basically female (1) and male (2)
And a resin supply device (not shown) for plasticizing and melting the thermoplastic transparent resin to supply the resin, and peripheral devices.

The apparatus as described above is used as illustrated below. First Step A transparent film (3) coated with a surface-hardened layer is provided between a mold-closable male mold (2) and female mold (1) in a continuous sheet state or in a state cut by an appropriate method. (FIG. 1) Second step The male mold is lowered to start the mold closing of the male mold (2) and the female mold (1), and the mold closing operation is stopped halfway or the mold closing speed is 30 mm / sec or less. Then, the cavity clearance (a) of the male mold (2) and the female mold (1) is (C +
When the thickness is 0.1) mm to (C + 7) mm, the thermoplastic transparent molten resin (4) is passed through a resin passage (not shown) provided in the female mold (1) between the transparent film and the female mold (1). To supply. However, C is the cavity clearance when the shaping is completed. (Fig. 2) Third step The male mold (2) is further lowered, and the molds are closed until the cavity clearances of both the female and male molds become the cavity clearances (C) at the time of completion of shaping, thereby making it transparent. The film (3) and the thermoplastic transparent resin (5) are integrated to complete the molding, and a scratch-resistant transparent member is obtained. (FIG. 4) In the present invention, the cavity clearance (C) at the time of completion of shaping is the cavity clearance when the shaping is completed by compressing the transparent film (3) and the thermoplastic transparent resin (5). .

The thermoplastic transparent molten resin (4) is supplied in the second step of the present invention so that the cavity clearance (a) between the male mold (2) and the female mold (1) is (C + 0.1) mm to (C).
It may be performed when +7) mm. When the cavity clearance is larger than (C + 7) mm, the surface of the thermoplastic transparent molten resin is cooled, and it is likely that the surface of the thermoplastic transparent molten resin contracts freely and becomes uneven, and this is transferred to the transparent film (3) to generate unevenness.

The cavity clearance is (C + 0.
If it is smaller than 1) mm, excessive heat and resin pressure are applied near the supply port for the molten resin, and the transparent film (3) near the supply port.
Defects such as depressions and irregularities are likely to occur. In the present invention, the cavity clearance (a) is reliably controlled within a range of (C + 7) mm to (C + 0.1) mm, and the mold closing operation of the male / female molds is temporarily stopped, or Mold closing speed is 30mm
/ Sec or less, the thermoplastic transparent molten resin (4) is supplied between the transparent film and the male or female mold.

By this method, the supplied resin spreads outward so as to be squeezed out as shown in FIG. 3, and it is relieved that heat is intensively applied to the vicinity of the supply port, so that the appearance of the transparent film is improved. You can keep good. When the mold closing speed is higher than 30 mm / sec, an excessive pressure is applied to the transparent film near the supply port, so that the appearance of the transparent film is likely to be damaged. The mold closing speed is 0.
It is preferably performed at 1 to 20 mm / sec.

When the thermoplastic transparent molten resin is supplied with the mold closing operation temporarily stopped in the second step, the mold closing of the molding in the subsequent third step is performed before or after the supply of the molten resin is completed. It is particularly preferred to start at the same time.

When the thermoplastic transparent molten resin is supplied into the mold cavity through the resin passage (8) provided in the mold, the position of the supply port (referred to as a gate portion) is not particularly limited. You can freely design according to the design of the product, not what you receive. The number of gates may be one or plural.

Since the appearance of the transparent member of the present invention is often regarded as important, it is preferable to use a mold having a product forming portion and a non-product forming portion and to provide the gate portion on the non-product forming portion. Bring The product part is the part of the molded product that is provided as a product, and the non-product part is
A part of a molded product that is not useful as a product and is cut off or hidden on the back surface during use.

A large product having a large projected area is suitable for shaping.

For the thermoplastic transparent resin, various kinds of materials can be used depending on the purpose of use and required performance.

Specific examples include acrylic resins, polycarbonates, polystyrenes, AS resins, ABS resins, polyvinyl chloride resins, polyester resins and acetate resins. Among them, acrylic resin is transparent,
It is particularly preferably used because it exhibits excellent properties in terms of surface gloss and weather resistance.

Examples of acrylic resins include general-purpose acrylic materials, impact-resistant acrylic materials, and heat-resistant acrylic materials.

As the general-purpose acrylic material, a polymer containing methyl methacrylate as a main component is generally used. As the polymer, a methyl methacrylate homopolymer, methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-methacrylate is used. Examples thereof include a copolymer obtained by copolymerizing a copolymerization component such as an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms such as ethylhexyl acrylate at a content of 15% or less.

The impact-resistant acrylic material means methyl methacrylate containing 1 to 1 of butadiene, substituted butadiene and an alkyl group.
Impact resistance is imparted by copolymerizing a rubber component such as a polymer of eight alkyl acrylates.

As the heat-resistant acrylic material, methylmethacrylate and α-methylstyrene, maleic anhydride, N-
Those obtained by copolymerization with a vinyl-based monomer such as substituted maleimide, or those introduced with a ring structure such as glutaric acid and glutaric imide are used.

The transparent film used in the present invention includes acrylic resin, polycarbonate, polystyrene and AS.
Examples of the transparent film include resin, ABS resin, polyvinyl chloride resin, polyester resin, and acetate resin. Among them, acrylic resin is transparent, surface gloss,
It is particularly preferably used because it shows excellent properties in terms of weather resistance.

The transparent film is manufactured by T-die extrusion or inflation molding and has a thickness of 0.05 m.
m-1 mm is used, preferably 0.1 mm
A transparent film having a thickness of ~ 0.3 mm is preferably used. When the film thickness is less than 0.05 mm, wrinkles are easily formed on the transparent film when the thermoplastic transparent molten resin is supplied, while when the film thickness exceeds 1 mm, the thermoplastic transparent molten resin serving as the core material is supplied, When shaping, shaping becomes difficult due to the return (spring back) due to the rigidity of the transparent film. In order to avoid the above spring back, a method of heating and molding the transparent film in advance and then supplying and shaping the thermoplastic transparent molten resin is conceivable. However, this complicates the manufacturing process and causes a cost increase.

The transparent film is coated with a siloxane-based or polyfunctional acrylic surface-hardening agent, and examples of the siloxane-based surface hardening agent include a hydrolyzate of an alkoxysilane or a substituted alkoxysilane compound.

Specifically, US Pat. No. 3,451,838, JP-A-48-26221, JP-A-48-56230, JP-A-48-84878, and JP-A-50-40674,
JP-A-50-69184, JP-A-50-78639
JP-A-50-143822, JP-A-51-234
3, JP-A-52-52931, and JP-A-53-111.
No. 336, Japanese Patent Publication No. 47-3709, Japanese Patent Publication No. 47-32.
No. 416, Japanese Patent Publication No. 50-28446, Japanese Patent Publication No. 51-2
No. 343, Japanese Patent Publication No. 55-40631, Japanese Patent Publication No. 56-1
No. 8625, Japanese Patent Publication No. 56-39631, etc., silicon silane compounds such as alkoxysilane and substituted alkoxysilane and unsaturated groups,
It is a siloxane compound obtained by adding water, alcohol, an acid catalyst, etc. to an alkoxysilane compound having a functional group such as an epoxy group, an amino group, a mercapto group, etc. to cause a hydrolysis and condensation reaction.

The polyfunctional acrylate-based surface hardening agent is a polyfunctional acrylate-based surface hardening agent containing two or more acryloyloxy groups or methacryloyloxy groups in one molecule, and is disclosed in JP-A Nos. 50-82713 and 50-82713. 50-1
10477, JP-A-54-113693, JP-A-5
5-69670, JP-A-56-861, JP-A-56
-122840, JP-A-58-87117, JP-A-58-101121, JP-A-58-129018,
JP-A-63-68642, JP-A-63-168419
And Japanese Patent Application Laid-Open No. 1-174515.

The transparent film may be coated by various known methods such as brush coating, spray coating, dipping coating and roll coating, of which the roll coating is most preferably used. The conditions for curing the surface curing agent with heat or ultraviolet rays are set in consideration of the type of the surface curing agent, the mechanical properties of the transparent film, the heat resistance and the like.

In using the transparent film (3),
In order to adjust the tensile stress and elongation of the transparent film, preheating may be carried out entirely or partially before the supply. Further, the vertical relationship between the female mold (1) and the male mold (2) and the mold closing direction can be freely selected, and further, the thermoplastic transparent molten resin (4)
May be supplied from the male mold (2) side or the female mold (1) side.

The transparent film may be set between the male mold (2) and the female mold (1) by using a supporting mechanism outside the mold, or a set pin provided in the peripheral portion of the mold. (7) Alternatively, a clamp mechanism may be used.

Further, depending on the shape of the product, the transparent film (3) may be simply placed on the lower mold, and at this time, the supporting force of the transparent film (3) is the male mold (2) and the female mold (2). The shear clearance (b) of 1) is 0.1 to 1.0 m
It can be controlled by setting it to about m. Less than,
The present invention will be described more specifically by way of examples.

(Evaluation Method) (1) Surface Hardness The abrasion resistance was evaluated by rubbing with steel wool of # 1000. A: No scratches even with strong rubbing. B: Scratches slightly when rubbed strongly. C: Slightly scratched with slight rubbing. D: Significantly scratched even with light rubbing. (2) Adhesion (cross-cut peeling test) Using a cutter knife, insert 11 coating cutting lines each reaching the base material at 1 mm intervals to make 100 squares of 1 mm.
Make an individual piece, attach the cellophane tape on it, and peel it off suddenly. This cellophane tape peeling operation was carried out three times at the same location, and the degree of adhesion was expressed by the number of stitches that did not peel. (3) Durability (hot water immersion test) After soaking in hot water of 80 ° C. for 200 hours, a sample is taken out and the above-mentioned cross-cut peeling test is performed to evaluate the adhesion. (4) Swarf The transparent member was placed on a flat plate, and when it was pressed from above, it was represented by the largest number of the heights that floated.

A Preparation of A Siloxane Surface Hardening Agent (1) Synthesis of Siloxane Compound A hydrolysis vessel equipped with a reflux condenser was charged with 68 g of isopropyl alcohol, 38 g of tetraethoxysilicon and 72 g of methyltriethoxysilicon, mixed and dissolved, and further mixed. 36 g of 0.05 N hydrochloric acid aqueous solution was added, and the solution was heated and refluxed for 5 hours while stirring to carry out cohydrolysis. After the reaction, the mixture was cooled to room temperature to obtain a cohydrolyzate. (2) Preparation of surface hardening agent To 100 parts of the above-mentioned siloxane compound, 40 parts by weight of n-butanol, 40 parts by weight of acetic acid, and 20 parts by weight of xylene were added and dissolved, 0.4 parts by weight of sodium acetate, and a surface active agent manufactured by Nippon Unicar Co., Ltd. 0.2 parts of NUC Silicon Y7006 was added and dissolved to prepare a siloxane-based surface hardening agent.

B Preparation of polyfunctional acrylate-based surface curing agent (1) Synthesis of dipentaerythritol hexaacrylate In a 1 liter glass reactor equipped with a stirrer, thermometer, and water separator, 127 g of dipentaerythritol and acrylic acid. 259 g, mixed solvent (benzene / cyclohexane = 2/1) 127 g, sulfuric acid 6.3 g, copper sulfate 0.51
g, and 0.03 g of hydroquinone monomethyl ether. While stirring and blowing air, the reaction is carried out under reflux, the distilling organic solvent and the water azeotrope are separated from water, and the organic solvent is allowed to return to the reaction system for reaction to react with water.
2 cc was run off and removed. Next, the reaction liquid was cooled, 254 g of a mixed solvent (benzene / cyclohexane = 2/1) was added, and the mixture was neutralized with a 10% aqueous caustic soda solution, separated, and washed with 10% saline. Then, the oil layer was dried over anhydrous magnesium sulfate, the mixed solvent was removed under reduced pressure at 50 to 60 ° C., and 271 g of dipentaerythritol hexaacrylate was obtained as the residue in the kettle. This viscosity is 9410 cps
(25 ° C.), the ester value was 552 (theoretical value 582.
It was 5).

(2) Synthesis of polyfunctional urethane acrylate In a 1 liter glass reactor equipped with a stirrer, thermometer and dropping funnel, 242 g of trimethylolpropane diacrylate and 0.2 of hydroquinone monomethyl ether were added.
5 g was put, the temperature was kept at 60 ° C., and 85 g of 2,4-tolylene diisocyanate was added dropwise over 1 hour. After dropping 1
After stirring for an hour, dibutyltin diacetate was added.
The reaction was further completed by adding 05 g and continuing the reaction for 2 hours to obtain 325 g of a polyfunctional urethane acrylate.
The isocyanate content of the polyfunctional urethane acrylate was 0.03%.

(3) Preparation of polyfunctional acrylate-based surface curing agent Dipentaerythritol hexaacrylate 250 and polyfunctional uretanacrylate 250 g prepared by the above method
Was dissolved in 467 g of xylene / 292 g of butyl acetate / 175 g of diacetone alcohol, and 7.5 g of 1-hydroxycyclohexyl phenyl ketone was added as a photosensitizer and mixed sufficiently to prepare a polyfunctional acrylate surface curing agent.

C Preparation of Transparent Film Coated with Siloxane Surface Hardening Agent Impact-resistant acrylic material Sumipex HT-55X manufactured by Sumitomo Chemical Co., Ltd. was extruded by the T-die method to 0.1.
A 5 mm extruded film is manufactured, and then the siloxane-based surface hardening agent of the above A is applied by a roll coater, air-dried, and once wound. Next, put it in a heating furnace at 80 ° C for 3 hours,
The heat curing reaction was completed, and a transparent film coated with a siloxane-based surface curing agent was obtained.

D Preparation of a transparent film coated with a polyfunctional acrylate-based surface curing agent A polyfunctional acrylate-based surface curing agent was prepared in the same manner as in the above C except that the siloxane-based surface curing agent was replaced with a polyfunctional acrylate-based surface curing agent. Was applied and air-dried, and then a high-pressure mercury lamp (manufactured by Eye Graphics, eye cure UEO21-
2 with 403C, 500V, H02-L41 (2)
Irradiate with UV light from a distance of 50 mm at 120 W for 5 seconds,
A surface-cured coating was formed to prepare a transparent film coated with a polyfunctional acrylate-based surface curing agent.

[0041]

【Example】

Example 1 An automotive glazing member having a thickness of 3 mm as shown in FIG. 5 is obtained by using a mold having a thermoplastic transparent molten resin supply port in a non-product forming portion of a lower mold. As a thermoplastic transparent resin, Sumitomo Chemical Co., Ltd. polymethylmethacrylate resin Sumipex MH (melt flow rate 2.0 g / 1
0 minutes), using a transparent film coated with a surface-cured layer of the siloxane-based surface curing agent of C as a transparent film, a scratch-resistant vehicle glazing member was subjected to the following conditions by the method described in FIGS. Shaped with. The transparent member had no tears and wrinkles and had a good appearance.
The surface hardness was A, indicating good scratch resistance. The cross-cut adhesion of the cured coating was as good as 100/100, and the adhesion did not change even after the hot water immersion test. The warp of the molded product was 1 mm or less. Resin temperature 260 ℃ Mold temperature 60 ℃ Cavity clearance at the start of supply 7m
m Cavity clearance after completion of shaping 3m
m type closing speed 10m
m / sec

Comparative Example 1 A molded product was obtained using the same resin as in Example 1 and the same resin temperature and mold temperature as the conventional injection mold, but a wrinkle was found near the gate. It entered and became poor in appearance. Further, the warp of the molded product is 4 mm, which is 1 mm in Example 1.
It is bigger than the following.

Example 2 A glazing member was obtained under the same conditions as in Example 1, using a transparent film coated with a surface-cured layer of the above-mentioned polyfunctional acrylate-based surface curing agent of D as the transparent film.
The surface hardness was A, indicating good scratch resistance. The cross-cut adhesion of the cured coating was as good as 100/100, and the adhesion did not change even after the hot water immersion test.

Comparative Example 2 A molded product was obtained using the same resin as in Example 2 with the same resin temperature and mold temperature and using a conventional injection molding mold, but wrinkles were observed near the gate. It entered and became poor in appearance. Further, the warp of the molded product is 4 mm, which is 1 mm in Example 1.
It is bigger than the following.

Example 3 Acrylic imide resin KAMAX T-240 manufactured by Rohm and Haas Co., Ltd. was used as the core resin, and a transparent film coated with a surface-cured layer of the above C siloxane-based surface curing agent was used as the transparent film. Then, the scratch-resistant vehicle glazing member was shaped under the following conditions by the method described with reference to FIGS. The above member has no tears and wrinkles,
The appearance was good. The surface hardness was A, indicating good scratch resistance. The cross-cut adhesion of the cured coating is 10
It was as good as 0/100, and the adhesiveness did not change even after the hot water immersion test. Resin temperature 280 ℃ Mold temperature 80 ℃ Cavity clearance at the start of supply 8m
m Cavity clearance at completion of shaping 3m
m type closing speed 10m
m / sec

Comparative Example 3 A molded product was obtained using the same resin as in Example 3 with the same resin temperature and mold temperature and using a conventional injection molding mold, but wrinkles were found near the gate. It entered and became poor in appearance. In order to observe the optical distortion of the molded product, the molded product was mounted on a crossed Nicols type polarizer and observed. As compared with Example 3, the degree of polarization was observed to be larger. The warp of the molded product is 4 mm
Then, it was larger than 1 mm or less in Example 1.

[0047]

According to the present invention, a scratch-resistant transparent member can be efficiently produced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a press molding die of the present invention.

FIG. 2 is a vertical cross-sectional view of a press molding die of the present invention.

FIG. 3 is a vertical cross-sectional view of a press molding die of the present invention.

FIG. 4 is a vertical cross-sectional view of a press molding die of the present invention.

FIG. 5 is a perspective view of an automobile glazing member.

[Explanation of symbols]

1. Female 2. Male type 3. Transparent film 4. 4. Thermoplastic transparent molten resin 5. Thermoplastic transparent resin 6. Scratch-resistant transparent member 7. Set pin 8. Resin passage 9. Product forming part of automotive glazing material 10. Non-product forming part of automotive glazing member a. Cavity clearance when supplying thermoplastic transparent molten resin b. Shear clearance c. Cavity clearance upon completion of shaping

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B32B 27/00 B 8413-4F 27/08 8413-4F B29L 9:00 4F

Claims (5)

[Claims] 1. A first step of (a) disposing a transparent film (3) coated with a surface-hardened layer between a male mold (2) and a female mold (1), and (b) a male mold (2). Start closing the female mold (1),
With the mold closing operation being stopped midway or with the mold closing speed set to 30 mm / sec or less, the male mold (2)
And the cavity clearance (a) of the female mold (1) is (C
Second step of supplying the thermoplastic transparent molten resin (4) between the transparent film (3) and the male mold (2) or female mold (1) when it is +0.1) mm to (C + 7) mm (However, C is the cavity clearance when the shaping is completed),
(C) A third step of shaping by closing the male mold (2) and the female mold (1) until the cavity clearance (C) is reached,
A method for producing a scratch-resistant transparent member, comprising: 2. The method for producing a scratch-resistant transparent member according to claim 1, wherein the surface-hardened layer is a surface-hardened layer using a siloxane-based thermosetting surface-hardening agent. 3. A transparent film coated with a surface-cured layer of a polyfunctional acrylate-based surface-curing agent having two or more acryloyloxy groups or methacryloyloxy groups in one molecule is used. A method for producing the scratch-resistant transparent member as described. 4. The method for producing a scratch-resistant transparent member according to claim 1, wherein the transparent film is an acrylic film. 5. The method for producing a scratch-resistant transparent member according to claim 1, wherein the scratch-resistant transparent member is a vehicle glazing member.