JPS643666B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vinyl chloride resin laminate having a fluororesin film on its surface, and particularly to a vinyl chloride resin laminate having a fluororesin film adhered to it via a specific adhesive. Vinyl chloride resin (hereinafter referred to as PVC) is used in various molded products for many purposes, but PVC flat plates and
Corrugated sheets, films, etc. are widely used. this
PVC flat plates, corrugated plates, films, etc. have particular problems with weather resistance, and are known to be severely degraded by UV rays. Furthermore, although PVC has excellent corrosion resistance, it does not necessarily provide sufficient corrosion resistance in all aspects, and even higher corrosion resistance is sometimes required. On the other hand, fluororesins are known as resins with extremely high corrosion resistance. Furthermore, such fluororesins have extremely high weather resistance compared to PVC, and also have the advantage of being less susceptible to dirt and the like. Therefore, if a laminate can be manufactured by laminating a fluororesin film onto the surface of PVC, it is expected that a PVC laminate with extremely excellent weather resistance, corrosion resistance, and non-staining properties will be obtained. However, not only fluororesin but also PVC has poor adhesive properties, and even if the two are laminated by heating and pressurizing them, they will hardly adhere to each other. Therefore, an adhesive is required to laminate the two, but there has been almost no known adhesive that can firmly bond the two. In order to bond fluororesin, it is highly necessary to activate the surface of the fluororesin, but even if activation treatment is performed, there is no adhesive that can bond fluororesin with high adhesive strength. rare. Conventionally, it has been known to laminate and integrate a fluororesin made of ethylene-tetrafluoroethylene copolymer with PVC, polyolefin resin, etc. (see, for example, Japanese Patent Laid-Open No. 58588/1988). Epoxy resin adhesives and cyanoacrylate adhesives are used as adhesives for lamination, but these adhesives have not yet achieved sufficient adhesive strength. In particular, it is insufficient for laminating fluororesin and PVC, and there is a need for an adhesive with even higher bonding strength. For the purpose of producing a laminate of PVC and fluororesin film, the present inventors searched for adhesives that could firmly bond the two, and examined the adhesive strength using them. As a result, it has been found that hot melt adhesives such as saturated polyester and polyolefin adhesives exhibit excellent adhesive properties. The present invention is a laminate of PVC and fluororesin film laminated using this adhesive, that is, a hot melt adhesive in which a fluororesin film is made of a saturated polyester resin on at least one side of a vinyl chloride resin. This is a vinyl chloride resin laminate characterized in that it is laminated via a mixture of a polyvinyl chloride resin and an isocyanate crosslinking agent. Rigid PVC is particularly suitable as PVC in the present invention. PVC with soft plasticizer added
is not very preferable because the adhesive strength tends to decrease due to reasons such as plasticizer bleed. but,
As long as the amount of plasticizer is small, it may be less of a problem.
PVC includes, of course, vinyl chloride homopolymer,
It may also be a copolymer with a small amount of other polymerizable monomer. PVC also contains stabilizers, UV stabilizers,
Fillers, colorants, fibrous reinforcing agents, lubricants, plasticizers,
Alternatively, other additives may be added. Examples of fluororesins include single α,β-unsaturated compounds containing fluorine atoms such as ethylene tetrafluoride, chloroethylene trifluoride, vinylidene fluoride, vinyl fluoride, propylene hexafluoride, and perfluorovinyl ether. It is a polymer or copolymer, and as a copolymerization component, in addition to the above-mentioned α,β-unsaturated compound having a fluorine atom, ethylene is often used, but a small amount of other components are also used. There is also. Specifically, for example, homopolymers of ethylene tetrafluoride, ethylene trifluoride chloride, vinylidene fluoride, and vinyl fluoride, ethylene-ethylene tetrafluoride copolymers, and ethylene-ethylene chloride trifluoride copolymers Combined, tetrafluoroethylene
Hexafluoropropylene copolymers, tetrafluoroethylene-perfluorovinyl ether copolymers, and the like are widely known. In the present invention, any of these can be used, but in view of the adhesive strength that can be achieved, vinylidene fluoride homopolymer, ethylene-tetrafluoroethylene copolymer, and ethylene-trifluoroethylene chloride copolymer are preferred. Combination is preferred.
Particularly preferred is an ethylene-tetrafluoroethylene copolymer, in which the molar ratio of ethylene/tetrafluoroethylene is
Copolymers having a ratio of 30/70 to 60/40 and optionally containing small amounts of other copolymer components are suitable. Various additives can be added to this fluororesin film. Particularly preferred is the addition of an ultraviolet absorber. Ordinary fluororesin films allow UV rays to pass through, so the PVC underneath the fluororesin film is easily affected by the transmitted UV rays. Therefore, when the purpose is to improve weather resistance, it is preferable that the fluororesin film is difficult to transmit ultraviolet rays, so adding an ultraviolet absorber to the fluororesin film is an appropriate means. Note that a similar effect can also be achieved by adding an ultraviolet absorber to the hot melt adhesive. The surface of these films made of fluororesin is usually subjected to activation treatment before lamination. This surface activation treatment greatly improves the adhesive strength. Activation treatments include electrical discharge treatment, metal sodium treatment, flame treatment, sand blasting, and other chemical or physical treatment methods.In the present invention, all of these methods are effective to some extent, but the particularly preferred treatment method is electrical discharge treatment. It is processing. In particular, electric discharge treatment is most suitable for treating ethylene-tetrafluoroethylene copolymer films. A fluororesin film is attached to at least one side of the PVC. If one side is exposed outdoors, a laminate with a fluororesin film attached to one side is often sufficient, but if both sides are exposed outdoors, it is preferable to attach fluororesin films to both sides. . The thickness of the fluororesin film is not particularly limited, but it is preferably about 6 to 500 microns, and particularly from the viewpoint of film production and economical efficiency, about 10 to 300 microns is appropriate. The thickness of PVC is not particularly limited, as long as it can be used as a film or a structural material. Highly flexible materials such as films are used as agricultural films, and those with a thickness of at least 0.5 mm are used as structural materials. The upper limit of the thickness is not limited, and a thickness that is normally used as a plate is used. As the hot melt adhesive, one made of saturated polyester resin is used. Saturated polyester hot melt adhesives include esterification of aromatic dibasic or aliphatic dibasic acids such as terephthalic acid, isophthalic acid, and orthophthalic acid with polyhydric alcohols such as ethylene glycol and 1,4-butanediol. Especially, saturated polyesters containing terephthalic acid as the main acid component are excellent. The molecular weight of saturated polyester is 3000~
A suitable molecular weight is about 25,000, and particularly preferred is a saturated polyester having a molecular weight of about 15,000 to 25,000.
Since these have residual hydroxyl groups and carboxylic acid groups at their terminals, they can be crosslinked with organic polyisocyanate, and the adhesive strength is improved by using a crosslinking agent. Further, the forms include films, powders, granules, solutions, etc. In the case of films, they can be laminated as they are, while powders etc. are used by making a solution and applying it to the adhesive surface. Specific commercially available saturated polyester hot melt adhesives include, for example, the product name "Vylon" sold by Toyobo Co., Ltd. Lamination of PVC and fluororesin film is carried out by applying pressure and heating through a mixture of a hot melt adhesive made of a saturated polyester resin and an isocyanate crosslinking agent. As mentioned above, if the hot melt adhesive is in sheet form, it can be used as is, or if it is in solution form, it can be applied to the adhesive surface of PVC or fluororesin film, or both adhesive surfaces, and then dried. Heating during lamination is carried out at 50°C to 200°C, and pressure is applied at about 10 to 150 kg/cm ² . At the time of this lamination, shaping such as making a flat plate into a corrugated plate may be performed. The PVC laminate of the present invention has particularly excellent weather resistance, corrosion resistance, and non-staining properties, so it is ideal as a building construction material exposed to the outdoors, where these are problematic. Especially used as roofing and sidewall materials.
Since many PVC plates are corrugated, the laminate of the present invention is preferably a corrugated sheet. Traditionally used as roofing material
Although PVC corrugated plates have been widely used, they deteriorate severely and cannot be used for long periods of time.
Compared to this, PVC laminated corrugated sheets are much more weather resistant.
It has excellent corrosion resistance and can be used for a long time. PVC laminated corrugated sheets with a fluororesin film on one side are used as roofing materials, but partition plates used outdoors are often exposed to sunlight on both sides, so it is best to use a fluororesin film on both sides. PVC laminated corrugated board with is suitable. It can also be used as an agricultural film in the same way as conventional PVC films, in which case the weather resistance is particularly improved. EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited only to these Examples. Example 1 Thickness of ethylene-tetrafluoroethylene copolymer polymer trade name “Afrex” (manufactured by Asahi Glass Co., Ltd.)
One side of a 25μ film is subjected to electrical discharge treatment, and a roll coater is used to coat this side with a solution adhesive made of a linear high molecular weight terephthalic acid-based saturated polyester resin (trade name: "Vylon" 50AS (manufactured by Toyobo Co., Ltd.). ) and an isocyanate-based crosslinking agent (product name “Coronate HL”) (manufactured by Nippon Polyurethane Co., Ltd.).
It was mixed in a 100:3 ratio, applied and air dried.
Next, two sheets of Afflex film coated with this adhesive were stacked with two sheets of 0.5 mm hard vinyl chloride calender sheets in the middle with the adhesive coated side facing inside, and heated to a temperature of 165℃ and a pressure of 40Kg/cm ² using a hydraulic press. A transparent laminate was obtained by pressure bonding for 5 minutes. On the other hand, as a comparative sample, a 0.5 mm hard vinyl chloride calender sheet was press-molded using the same hydraulic press at a temperature of 165°C and a pressure of 60 kg/cm ² for 10 minutes to produce a transparent hard vinyl chloride plate. Afrex - The tensile strength of PVC laminate is 6.5
It was found that the AFLEX-PVC laminate had better weather resistance than the hard PVC board, although the Kg/mm ² was not much different from the hard PVC board comparison sample. In other words, after conducting a weather resistance test in accordance with the JIS-A1411 measurement method for 800 hours (equivalent to approximately 4 years), the Afrex-PVC laminate showed almost no coloration (the light transmittance also changed from 802% to 89.6%, with almost no change). ), the tensile impact test using a dumbbell-shaped punched specimen was
Initial strength 285Kg-cm/ ^cm2 vs. 257Kg after 800 hours
-cm/cm ² and the strength retention rate was 90%. The comparative sample had an initial strength of 277 Kg-cm/cm ² , but after the 800-hour weather test, it showed 174 Kg-cm/cm ² , which was a decrease in strength retention of 63%. The physical property values are shown in the table.

[Table] Example 2 A solution adhesive made of linear high molecular weight terephthalic acid-based saturated polyester resin (trade name: "Vylon") was applied to one side of a 0.25 mm thick hard vinyl chloride resin calendar sheet using a dry laminator device.
A mixture of 50AS (manufactured by Toyobo Co., Ltd.) and an isocyanate-based crosslinking agent (trade name: Coronate HL) (manufactured by Nippon Polyurethane Co., Ltd.) in a ratio of 100:3 is applied and air-dried to form a 25μ flex film. A laminated film was temporarily crimped using a crimping roll. Two 0.25 mm hard vinyl chloride calender sheets were further stacked on the vinyl chloride surface of this Afrex-hard vinyl chloride laminated film, and heated using a hydraulic press.
Pressure was applied at 165° C. and at a pressure of 40 Kg/cm ² for 10 minutes to obtain a transparent laminate. This laminate is made using a corrugating machine for 90
Corrugation was carried out while heating to ℃ to produce a laminated corrugated plate. After conducting the same weather resistance test as in Example 1, this corrugated sheet showed the same performance as Example 1, and was found to be a corrugated sheet with excellent weather resistance.

Claims (1)

[Scope of Claims] 1. A vinyl chloride resin, characterized in that a fluororesin film is laminated on at least one side of the vinyl chloride resin via a mixture of a hot melt adhesive made of a saturated polyester resin and an isocyanate crosslinking material. system resin laminate. 2. The laminate according to claim 1, wherein the vinyl chloride resin is a hard vinyl chloride resin. 3. The laminate according to claim 1, wherein the fluororesin is a fluororesin made of a copolymer of ethylene and tetrafluoroethylene or trifluoroethylene. 4. The laminate according to claim 1, wherein the adhesive surface of the fluororesin film is activated. 5. The laminate according to claim 5, wherein the activation treatment is a discharge treatment. 6. The laminate according to claim 1, wherein the laminate is a laminated corrugated plate.