JP4835183B2 - Polycarbonate resin molded body and barrier layer - Google Patents

Description

  The present invention is a polycarbonate resin molded article having antifogging properties used for helmet visors, goggles and the like, and has particularly improved chemical resistance while maintaining excellent processability and antifogging properties. The present invention relates to a molded body.

  Various transparent plastic materials have exteriors such as portable devices, household electrical appliances, industrial electronic devices, and automotive electronic devices from the viewpoint of lightness, transparency, processability, and resistance to cracking and safety. It is used as a protective cover for information displays, especially for monitors. Among plastic materials, the polycarbonate resin material is the most widely used material because of its excellent transparency, impact resistance, heat resistance and ease of processing. Among them, a polycarbonate resin molded body whose surface has been subjected to an antifogging treatment by coating or an antifogging film laminate is used for helmet visors, sports goggles and the like.

As the anti-fogging treatment method, a water film forming type method by applying a surfactant or making the surface layer hydrophilic, and a water absorbing type method for preventing fogging by forming a water absorbing layer on the surface are mainly used. Depending on the purpose, it is properly used. Among these, the method by applying a surfactant or the like is not durable, can only obtain a temporary effect, and has low anti-fogging properties, so that the usage that can be used is considerably limited. The water film formation method by hydrophilizing the surface has been put to practical use for applications that are always in a high humidity environment, such as prevention of water droplets on the inner surface of agricultural houses, inner surfaces of underwater goggles, and mirrors in bathtubs. On the other hand, there is a distortion of the image due to the water film to ensure visibility, not always high humidity, such as applications where water film moisture is hated, such as sensors and instrument covers, helmet visors, sports goggles, disaster prevention etc. In the application in question, a water absorption type anti-fogging treatment method is preferred and used.
JP 62-054733 A JP 04-211141 A JP 08-217992 A

  However, when water-absorbing anti-fogging treatment is applied to the polycarbonate resin base material, the chemical resistance of the polycarbonate resin is low, so it is a chemical substance contained in the fixing member when it is washed with detergent or a fixing member such as a gasket is attached. Even when the anti-fogging layer itself is not attacked when it comes into contact with, etc., chemical substances are absorbed into the anti-fogging layer and reach the interface with the polycarbonate resin, and the polycarbonate resin is attacked, resulting in dirt, cloudiness, cloudiness, etc. The occurrence of defects in the appearance of the film and the peeling of the anti-fogging treatment layer may occur, and improvement has been desired. Especially in helmet visors and goggles, white turbidity caused by the migration of chemical substances such as plasticizers contained in the soft resin when coming into contact with the soft resin gasket member and peeling of the anti-fogging layer become a problem. Yes.

  The present invention solves the above problems, and provides a polycarbonate resin molded article that is used in helmet visors, goggles, and the like, has excellent processability and antifogging properties, and has particularly improved chemical resistance. It is an object.

  The present inventor has found that the above problems can be solved by interposing a non-water-absorbing barrier layer between the polycarbonate resin base material and the antifogging layer, and has completed the present invention. That is, the present invention comprises a polycarbonate resin as a base material, a non-water-absorbing barrier layer as a first layer on at least one side of the base material, and a water-absorbing antifogging layer as a second layer on the first layer. The gist is a polycarbonate resin molded product characterized in that is formed.

  As described above, in the polycarbonate resin molded body of the present invention, a non-water-absorbing barrier layer is formed as a first layer on at least one surface of a polycarbonate resin base material, and a water-absorbing type is formed as a second layer on the first layer. By forming an anti-fogging layer, there is no effect on the polycarbonate resin base material even if it comes in contact with chemical substances, and the base material is affected by chemical substances, causing appearance defects such as dirt, cloudiness, cloudiness, etc. The anti-fogging treatment layer is not peeled off, and the effect of maintaining excellent workability and anti-fogging properties is exhibited, and it is suitably used for helmet visors and goggles.

  The first non-water-absorbing barrier layer is a composition that maintains transparency when formed on a polycarbonate resin base material, does not hinder workability such as thermoforming and cutting, and does not extremely reduce impact resistance. There is no particular limitation as long as it has higher chemical resistance than polycarbonate resin. Examples of the thermoplastic resin include polyvinyl chloride, polymethyl methacrylate, polystyrene, polyethylene terephthalate, and cyclic polyolefin.

  Examples of the method for forming the first layer include multilayer extrusion, thermal lamination, and coating. However, when the first layer is laminated on the polycarbonate resin substrate by multilayer extrusion or heat lamination, the thickness of the first layer is preferably 60 μm or less in order to maintain the workability and impact resistance of the polycarbonate resin laminate. Must be 30 μm or less, and it is not practical in terms of productivity and economy to form a thermoplastic resin layer on a polycarbonate resin by melt molding. It is also difficult to form a thermoplastic resin layer on polycarbonate by a solvent casting method.

  Therefore, what is practical in terms of productivity and economy is a method in which a liquid resin is coated on a polycarbonate resin substrate, and then dried and cured. As the liquid resin, an ultraviolet curable resin is most preferable. The UV curable resin has a high chemical resistance because it has a crosslinked structure, and can exhibit sufficient performance at a thickness of several μm to 30 μm. The processability and impact resistance of the polycarbonate resin laminate are sufficiently maintained. The

  When a thermosetting resin such as a silicone resin, epoxy resin, or melamine resin is used as the liquid resin, the base material is a polycarbonate resin, and thus the curing temperature is limited. It is forced to cure for a long time, and is not economical. In addition, the dry liquid resin has a problem that the effect of improving the chemical resistance is relatively low because the cross-linked structure is small. On the other hand, when an ultraviolet curable resin is used as the liquid resin, it can be dried at a low temperature of 80 ° C. or lower and cured for a short time with ultraviolet rays or an electron beam, so that the polycarbonate resin base material is not damaged. It is possible to form a barrier layer.

  As an ultraviolet curable resin used for the barrier layer of the first layer, a polyfunctional acrylate oligomer and a polyfunctional acrylate monomer are the main components, and in some cases, a monofunctional monomer or the like can be appropriately combined. In order to exhibit a sufficient function as a non-water-absorbing barrier layer, it is necessary to have a polyfunctional acrylate oligomer and a polyfunctional acrylate monomer as main components and to increase the crosslinking density to some extent. Functional acrylate monomers are used. However, in the case of only these oligomers and monomers, curing shrinkage is large, warping occurs, and workability and impact resistance as a polycarbonate resin molded product may be lowered. Therefore, in order to adjust the curing shrinkage and the crosslinking density and to obtain sufficient adhesion to the polycarbonate resin, it is preferable to use a combination of bifunctional or lower acrylate monomers.

<Multifunctional acrylate oligomer>
As the polyfunctional acrylate oligomer, urethane acrylate, epoxy acrylate, polyester acrylate, or the like can be used.

  The epoxy acrylate oligomer can be obtained, for example, by an esterification reaction between an oxirane ring of a low molecular weight bisphenol type epoxy resin or a novolak epoxy resin and acrylic acid. Moreover, as a polyester acrylate oligomer, it is obtained by esterifying the hydroxyl group of the polyester oligomer which has a hydroxyl group in the both ends obtained by condensation of polyhydric carboxylic acid and a polyhydric alcohol with acrylic acid, for example. Alternatively, it can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with acrylic acid.

  As the polyfunctional acrylate oligomer, it is most preferable to use a urethane acrylate oligomer. This is because a moderate crosslinking density can be obtained as a barrier layer, and the curing shrinkage is relatively small, and the processability and impact resistance as a polycarbonate resin molded article are less likely to be reduced compared to other oligomers. This urethane acrylate oligomer is a reaction product of an isocyanate compound obtained by reacting a polyol with diisocyanate and an acrylate monomer having a hydroxyl group. Examples of the polyol include polyester polyol, polyether polyol, and polycarbonate diol.

  Among urethane acrylate oligomers, it is particularly preferable to use a combination of difunctional to hexafunctional ones. This is because it is easy to obtain a sufficient crosslinking density as a barrier layer by using about 6 functional urethane acrylate, and it is possible to reduce curing shrinkage and moderate flexibility by using about 2 functional urethane acrylate. This is because it becomes possible to maintain the workability and impact resistance as a polycarbonate resin molded article.

  The manufacturing method of the said polyester polyol is not specifically limited, A well-known manufacturing method is employable. For example, the diol and dicarboxylic acid or dicarboxylic acid chloride may be subjected to a polycondensation reaction, or the diol or dicarboxylic acid may be esterified and subjected to an ester exchange reaction. Examples of the dicarboxylic acid include adipic acid, succinic acid, glutaric acid, pimelic acid, sebacic acid, azelaic acid, maleic acid, terephthalic acid, isophthalic acid, and phthalic acid. Examples of the diol include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, tripropylene glycol, and tetrapropylene glycol.

  As the polyether polyol, polyethylene oxide, polypropylene oxide, ethylene oxide-propylene oxide random copolymerization is used.

  Examples of the polycarbonate diol include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 2-ethyl-1,3-hexanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanediol, polyoxyethylene glycol, and the like are used, and one kind or two kinds You may use the above together.

  As the diisocyanate, a linear or cyclic aliphatic diisocyanate is used. Of course, aromatic diisocyanates can also be used, and it is possible to easily obtain excellent hard coat properties such as hardness and scratch resistance. On the other hand, polyfunctional oligomers are the main components that form the hard coat skeleton. This is because when the component is used, the light resistance is lowered, and yellowing easily occurs upon exposure to light, so that the function as a transparent hard coat is impaired in practical use. Representative examples of the linear or cyclic aliphatic diisocyanate include hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated xylylene diisocyanate.

  Examples of acrylate monomers having a hydroxyl group include trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol triacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate, Examples include polyethylene glycol monoacrylate.

<Multifunctional acrylate monomer>
Multifunctional acrylate monomers include dipentaerythritol hexaacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, ethoxy And pentaethylene erythritol triacrylate, ethoxylated pentaerythritol tetraacrylate, and polyethylene glycol diacrylate.

<Monofunctional monomer>
Monofunctional monomers include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate, polyethylene glycol monoacrylate, acryloyl morpholine, N vinyl pyrrolidone, N vinyl formamide, isobornyl An acrylate etc. are mentioned.

  The polycarbonate resin molded body of the present invention can be obtained by providing a water-absorbing antifogging layer as the second layer on the barrier layer of the first layer. The water-absorbing anti-fogging layer of the second layer has the water-absorbing performance necessary to obtain anti-fogging properties, maintains transparency when made into a polycarbonate resin laminate, and hinders workability such as thermoforming and cutting. The impact resistance is not particularly limited as long as the impact resistance is not extremely lowered. For example, a cellulose resin imparted with hydrophilicity by a saponification treatment or an ultraviolet curable resin coating film having a hydrophilic group in the molecule can be used.

  When an ultraviolet curable resin coating is used for the first layer and the second layer, it is necessary to add a photopolymerization initiator in the coating. The photopolymerization initiator has a function as a polymerization initiator when the photopolymerizable compound is cured by ultraviolet rays, and a known one can be used alone or in combination, such as benzoin, benzoin methyl ether, Benzoin or benzoin alkyl ethers such as benzoin ethyl ether and benzoin isopropyl ether, aromatic ketones such as benzophenone and benzoylbenzoic acid, alpha-dicarbonyls such as benzyl, benzyl ketals such as benzyldimethyl ketal and benzyl diethyl ketal, Acetophenone, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propan-1-one , 1- Acetophenones such as 4-isopropylphenyl) -2-hydroxy-2-methyl-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 2-methyl Anthraquinones such as anthraquinone, 2-ethylanthraquinone and 2-t-butylanthraquinone, thioxanthones such as 2,4-dimethylthioxanthone, 2-isopropylthioxanthone and 2,4-diisopropylthioxanthone, bis (2,4,6-trimethyl) Phosphine oxides such as benzoyl) -phenylphosphine oxide, alpha-acyloximes such as 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, ethyl p-dimethylaminobenzoate, p-Dimethylaminobenzoic acid It can be used amines such as isoamyl.

  Furthermore, in order to obtain a coating film having an excellent appearance, a surface conditioner such as a fluorine type or a modified silicone type is added to the paint. As the surface conditioner of fluorine type or modified silicone type, polyether type, alkyl type and polyester type can be used, but polyether type is particularly preferable. Acrylic copolymers are also commercially available as surface conditioners. These surface conditioners can also be used in combination.

  In addition, for the reason of providing design properties such as absorption, reflection, and coloring of specific wavelengths such as ultraviolet rays and infrared rays, the polycarbonate resin molded body of the present invention, either the first layer or the second layer, or All layers can be mixed with inorganic or organic fillers and additives as required.

The following ultraviolet curable resin paint was prepared for the first barrier layer.
A: Bifunctional urethane acrylate oligomer (trade name: Ebecryl EB8402
(Daicel UCB)
B: Hexafunctional urethane acrylate oligomer (trade name: Ebecryl EB1290, manufactured by Daicel UCB)
C: Bifunctional ethoxylated bisphenol A diacrylate (trade name: A-BPE4, Shin-Nakamura Chemical Co., Ltd.)
A: B: C was mixed at 50:30:20, and 0.005 wt% of an acrylic copolymer (trade name: BYK356 manufactured by Big Chemie) was added as a surface conditioner to this mixture. The coating material was prepared by diluting with a 50:50 mixed dilution solvent of isopropyl alcohol and butyl acetate so that the concentration of the solution was 20% by weight in the solution. At this time, a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) previously dissolved in isopropyl alcohol was diluted with a diluent solvent so as to be 5% by weight with respect to the resin content. Added as part. The paint thus prepared was thoroughly stirred and mixed, and then stored in a sealed container.

The following ultraviolet curable resin coating was prepared for the second antifogging layer.
D: Ethoxylated bisphenol A diacrylate (trade name: A-BPE20 manufactured by Shin-Nakamura Chemical Co., Ltd.)
E: N vinyl-2 pyrrolidone (trade name: NVP, manufactured by Maruzen Petrochemical Co., Ltd.)

D: E was mixed at 70:30, and 0.04 wt% of polyether-modified polydimethylsiloxane (trade name: BYK307 manufactured by Big Chemie) was added as a surface conditioner to this mixture. The coating material was prepared by diluting with a 50:50 mixed dilution solvent of isopropyl alcohol and butyl acetate so as to be 20% by weight in the solution. At this time, a photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone, trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals) previously dissolved in isopropyl alcohol was diluted with a diluent solvent so as to be 2% by weight with respect to the resin content. Added as part. The paint thus prepared was thoroughly stirred and mixed, and then stored in a sealed container.

Further, the following film was prepared for the second antifogging layer.
F: Saponified triacetyl cellulose film (50 μm thick, manufactured by Santox)

<Example 1>
A polycarbonate sheet having a thickness of 2.0 mm ("Polyca Ace" manufactured by Tsutsunaka Plastic Industry Co., Ltd.) was prepared, and the first layer of paint was applied using several types of metal bar coaters to a dry film thickness of 5 μm. . Next, this polycarbonate sheet was placed in a hot air circulation oven at 60 ° C. and dried for 10 minutes, and then placed on a conveyor with a distance of 25 cm and a speed of 10 m / min using an 80 W / cm metal halide lamp (manufactured by USHIO INC.). The polycarbonate sheet was irradiated with ultraviolet rays to cure the paint.

  Next, the coating material for the second layer was applied onto the first layer using a metal bar coater in the same manner as the first layer so that the dry film thickness was 20 μm. Further, after putting this polycarbonate sheet in a hot air circulation oven at 60 ° C. and drying for 10 minutes, a 160 W / cm high-pressure mercury lamp (manufactured by Ushio Inc.) was used and placed on a conveyor at a distance of 15 cm and a speed of 2.0 m / min. A polycarbonate resin molded body was obtained by irradiating the obtained polycarbonate sheet with ultraviolet rays.

<Example 2>
In the same manner as in Example 1, after forming the first layer, a polycarbonate resin molded body was obtained by laminating a film of F on the surface of the first layer by pressing a rubber roll whose temperature was adjusted to 140 ° C.

<Comparative Example 1>
In the same manner as in Example 1, a polycarbonate resin molded body was obtained by directly applying and drying the coating material for the second layer on the polycarbonate sheet without providing the first layer.

<Comparative example 2>
In the same manner as in Example 2, a polycarbonate resin molded body was obtained by directly laminating the F film on the polycarbonate sheet without providing the first layer.

The molded body obtained as described above was evaluated as follows. The results are shown in Table 1.
<Anti-fogging property>
Based on the measurement method of EN168, after the sample was held over a 50 ° C. hot water bath, the time until the light transmittance by the He—Ne laser became 80% of the initial value was defined as antifogging performance.
<Chemical resistance>
1 ml of acetone, which is a typical chemical that corrodes polycarbonate, is dropped on the anti-fogging surface, left at room temperature until it is naturally dried, and the appearance after drying is visually observed.

  In Examples 1 and 2, both showed good anti-fogging properties, showed no defects in appearance in the chemical resistance test, and could obtain a polycarbonate molded article excellent in chemical resistance. On the other hand, Comparative Example 1 and Comparative Example 2 were the same as in Examples in terms of antifogging properties, but there were problems with chemical resistance, and abnormalities such as cloudiness, cracks, and peeling occurred.

Claims (4)

The polycarbonate resin as a base material, on at least one surface of the substrate, non-water soluble first barrier layer is made of ultraviolet curable resin coating comprises a difunctional urethane acrylate oligomer and 6 officers Nou urethane acrylate oligomer, Furthermore polycarbonate resin molding, wherein a water-type antifogging layer is formed as a second barrier layer on top of the first barrier layer. The polycarbonate resin molded product according to claim 1, wherein the first barrier layer comprises an ultraviolet curable resin coating film containing a polyfunctional acrylate monomer. The polycarbonate resin molded article according to claim 1 or 2, wherein the second barrier layer comprises a water-absorbing ultraviolet curable resin coating film. An ultraviolet curable resin in which a first barrier layer of a polycarbonate resin molded article in which a water absorption type anti-fogging layer is formed as a second barrier layer on the first barrier layer includes a bifunctional urethane acrylate oligomer and a hexafunctional urethane acrylate oligomer The 1st barrier layer of any one of Claims 1-3 which consists of a coating film.