JPH0216773B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermoplastic acrylic resin film that is excellent in durability, particularly in protecting laminated substrates at high temperatures. Acrylic resin is a thermoplastic resin with excellent weather resistance, transparency, and gloss, and is therefore used in various molded products such as transparent plates, sheets, and injection molded products. Furthermore, recently, the impact resistance and mechanical properties of acrylic resin have been improved, making it possible to produce acrylic films with excellent weather resistance and processability. Such films include steel plates, plastic sheets,
It is used in the form of a colored film, a transparent film, or a printed film that is attached to a base material such as wallpaper or canvas for the purpose of imparting aesthetic appearance, improving durability, and corrosion resistance. However, among these films, transparent ones suffer from discoloration and physical property deterioration of the base material due to a decrease in tensile strength and elongation, and a decrease in ultraviolet shielding performance, although the effects of long-term exposure are more gradual than those without coating. Therefore, it is difficult to meet the purpose of durable use for 20 to 30 years. The present invention
The purpose is to improve this problem. In general, the deterioration of plastic outdoors is mainly due to deterioration due to ultraviolet rays in sunlight, and it is said that this is combined with oxygen in the air, moisture temperature, etc. to accelerate the deterioration. Therefore, in order to prevent deterioration, it is effective to prevent the action of ultraviolet rays. For this purpose, a method of adding pigments such as carbon black and titanium oxide, which block ultraviolet rays, has been adopted. However, at present, these methods do not allow for free coloring, have insufficient performance compared to the price, and are rarely satisfactory. For this reason, transparent films containing ultraviolet absorbers are often used. Currently, commercially available UV absorbers for this purpose, such as benzophenone-based, benzotriazole-based, substituted acrylonitrile-based, oxalic acid anilide-based, and salicylic acid ester-based ones, all sublimate or volatilize when heated. It has the disadvantage of being easily mixed and being difficult to be compatible with the resin used in the present invention. Especially when the temperature for forming the film is 200 to 250℃,
Even if an ultraviolet absorber is added, it will volatilize due to heat, so not much of the ultraviolet absorber will remain in the film, resulting in a significant reduction in the ultraviolet shielding effect. In addition, additives such as plasticizers and liquid stabilizers added to the base material to be laminated may migrate to the acrylic film layer or surface during outdoor use, and in this case, the ultraviolet absorber contained in the acrylic film may In some cases, chemicals may also be transferred and separated at the same time. For these reasons, long-term outdoor use causes significant discoloration and loss of gloss, and furthermore, a phenomenon occurs in which the anti-corrosion ability is reduced due to the occurrence of cracks on the surface. Another problem is that when the base material has a dark color tone, the surface temperature increases when exposed outdoors, and most of the ultraviolet absorbent evaporates out of the system due to the heat. The purpose of the present invention is to improve these drawbacks, and the content is that by adding an ultraviolet absorber having a specific function to a film made of a specific thermoplastic acrylic resin, A thermoplastic with excellent durability that can be laminated to a base material containing a plasticizer or liquid stabilizer and exhibit excellent weather resistance even when used outdoors at relatively high temperatures (60 to 100℃). The present invention provides an acrylic resin film. The film of the present invention includes soft and hard vinyl chloride, including vinyl chloride steel sheets, ABS resin,
Laminated with polycarbonate, polyolefin, polyester, etc., it is suitable for long-term outdoor use. The first aspect of the present invention is the following ultraviolet absorber (X)
A thermoplastic acrylic resin film containing the following acrylic resin (Y ₁ ). (X) General formula below (In the formula, R ₁ and R ₂ represent hydrogen or an alkyl group having 1 to 6 carbon atoms, and R ₃ represents hydrogen or chlorine.) (Y ₁ ) Acrylic acid alkyl ester (alkyl group) methacrylic acid alkyl ester (alkyl group having 1 to 8 carbon atoms) and 95 to 80 parts by weight of
4) A crosslinked elastomer component (A) consisting of 5 to 20 parts by weight and 0 to 10 parts by weight of another monomer copolymerizable with the above monomer, crosslinked by copolymerization of a crosslinkable monomer. Ten
In the presence of ~50 parts by weight, 10 to 60 parts by weight of an acrylic acid alkyl ester (having a carbon number of 1 to 8 in the alkyl group) and a methacrylic acid alkyl ester (having a carbon number of 1 to 8 in the alkyl group) as the first stage resin component (B). 1-4) 90
90-50 parts by weight of a monomer mixture consisting of ~40 parts by weight and 0-20 parts by weight of other monomers copolymerizable with the above monomers
Acrylic resin made by adding and copolymerizing parts by weight. The second aspect of the present invention is the following ultraviolet absorber (X)
A thermoplastic acrylic resin film containing the following acrylic resin (Y ₂ ). (X) General formula below (In the formula _, R ₁ and R ₂ represent hydrogen or an alkyl group having 1 to 6 carbon atoms, and R ₃ represents hydrogen or chlorine.) 95 to 80 parts by weight of methacrylic acid alkyl ester (alkyl group having 1 to 8 carbon atoms)
4) A crosslinked elastomer component (A) consisting of 5 to 20 parts by weight and 0 to 10 parts by weight of another monomer copolymerizable with the above monomer, crosslinked by copolymerization of a crosslinkable monomer. Ten
In the presence of ~50 parts by weight, 10 to 60 parts by weight of an acrylic acid alkyl ester (having a carbon number of 1 to 8 in the alkyl group) and a methacrylic acid alkyl ester (having a carbon number of 1 to 8 in the alkyl group) as the first stage resin component (B). 1-4) 90
90-50 parts by weight of a monomer mixture consisting of 40 parts by weight and 0-20 parts by weight of other monomers copolymerizable with the above monomers
Part by weight is added and copolymerized, and the second stage of resin component (C) is further added.
100 to 60 parts by weight of methacrylic acid alkyl ester (alkyl group having 1 to 4 carbon atoms) and acrylic acid alkyl ester (alkyl group having 1 to 4 carbon atoms)
8) Monomer mixture consisting of 0 to 40 parts by weight and 0 to 10 parts by weight of other monomers copolymerizable with the above monomers.
A thermoplastic acrylic resin film made by copolymerizing 50 to 100 parts by weight. The content of each is as follows. The ultraviolet absorber used in the present invention has the following general formula: (In the formula, R ₁ and R ₂ are hydrogen or an alkyl group having 1 to 6 carbon atoms, and R ₃ is hydrogen or chlorine.) Benzotriazole or its derivatives are represented by the following structural formula: 2-[2-Hydroxy 3,5-bis(γγ-dimethylbenzyl)phenyl]benzotriazole represented by is highly compatible with the thermoplastic acrylic resin of the present invention, does not reduce transparency, and can be used during film molding. It provides favorable results in that it does not volatilize and has excellent long-term durability for outdoor use. In the present invention, the ultraviolet absorber is used in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the resin. The thermoplastic acrylic resin used in the present invention is not particularly limited, and has good compatibility with the ultraviolet absorber used in the present invention, giving suitable results, but in particular, acrylic acid alkyl ester ( 95 to 80 parts by weight of alkyl group having 1 to 8 carbon atoms and methacrylic acid alkyl ester (alkyl group having 1 to 8 carbon atoms)
-4) A crosslinked elastomer component (A )
In the presence of 10 to 50 parts by weight, 10 to 60 parts by weight of acrylic acid alkyl ester (alkyl group having 1 to 8 carbon atoms) and methacrylic acid alkyl ester (carbon number of alkyl group) Numbers 1-4) 90
90-50 parts by weight of a monomer mixture consisting of ~40 parts by weight and 0-20 parts by weight of other monomers copolymerizable with the above monomers
A thermoplastic acrylic resin obtained by adding and copolymerizing parts by weight is suitable. The acrylic acid alkyl ester used in the crosslinked elastomer component of the present invention has an alkyl group with 1 carbon number.
~8 and may be linear or branched. Examples include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, etc., but in order to obtain an effective elastic material for strengthening, monomers with a low glass transition temperature such as n-butyl and 2-ethylhexyl are used. mer is preferred. The amount of acrylic acid alkyl ester is preferably in the range of 95 to 80 parts by weight. The methacrylic acid alkyl ester to be copolymerized with this is an alkyl group having 1 to 4 carbon atoms, and may be linear or branched. Methyl methacrylate is a typical example, and other examples include ethyl methacrylate, propyl methacrylate, and butyl methacrylate. In order to increase the impact strength and elongation of the film and to improve the transparency, it is preferable to copolymerize 5 to 20 parts by weight of methacrylic acid alkyl ester in the crosslinked elastomer component. Furthermore,
Other monomers that can be copolymerized with the monomers are 0 to 0.
It can be copolymerized within a range of 10 parts by weight. Next, the crosslinkable monomer to be copolymerized with acrylic acid alkyl ester and others is a monomer containing two or more copolymerizable carbon double bonds in one molecule.
Examples include monomers such as divinylbenzene, diallyl phthalate, mono- or polyethylene glycol dimethacrylate, allyl methacrylate, and triallyl cyanurate, and the amount used is preferably in the range of 0.1 to 8 parts by weight. be. The resin component monomer is added and copolymerized in the presence of 10 to 50 parts by weight of this crosslinked elastomer component, but if the amount of the crosslinked elastomer component is less than 10 parts by weight, the impact resistance and elongation of the film will be low. If it exceeds 50 parts by weight, the surface hardness tends to be poor. The acrylic acid alkyl ester and methacrylic acid alkyl ester used in the first stage (B) of the resin component are the same as those used in the crosslinked elastomer component described above. In this case, since the impact resistance and elongation of the film obtained with methacrylic acid alkyl ester alone are low, acrylic acid alkyl ester
It is desirable to copolymerize at least part by weight. But 60
If the amount exceeds the weight part, the surface hardness of the film tends to decrease. Furthermore, at this stage, the crosslinked elastomer component
It is desirable to select polymerization conditions to increase the grafting rate to (A). If such a resin is used, it has particularly good compatibility with the ultraviolet absorber used in the present invention, so even if left under high temperature conditions, the ultraviolet absorber will hardly volatilize, and therefore it will have excellent durability. The use of such specific resins can impart appropriate flexibility, impact strength, and elongation to the film, making it resistant to post-processing, such as roll forming and 180° bending, when laminated onto metal plates or plastics as coating films. You can get something useful. Examples of other monomers used in the present invention include vinyl halides such as vinyl chloride and vinyl fluoride; vinyl cyanides such as acrylonitrile and methacrylonitrile; vinyl esters such as vinyl acetate and vinyl propionate; styrene. , aromatic vinyl derivatives such as α-methylstyrene; vinylidene halides such as vinylidene chloride and vinylidene fluoride;
Acrylic acid and its salts such as acrylic acid, sodium acrylate, and calcium acrylate; acrylic acid ester derivatives such as β-hydroxyethyl acrylate, dimethylaminoethyl acrylate, glycidyl acrylate, acrylamide, and N-methylolacrylamide; methacrylic acid,
Methacrylic acid and its salts such as sodium methacrylate and calcium methacrylate; methacrylamide, N-methylolmethacrylic acid amide, β-hydroxyethyl methacrylate,
Methacrylic acid ester derivatives such as glycidyl methacrylate can be mentioned. Furthermore, as the second stage resin component (C), a methacrylic acid alkyl ester is used as the main component, and by copolymerizing this with an acrylic acid alkyl ester and other monomers that can be copolymerized with these monomers. , processability, hardness, and softening temperature can be improved. The monomers used as the second stage (C) of the resin component include 100 to 60 parts by weight of alkyl methacrylate having an alkyl group of 1 to 4 carbon atoms and an alkyl acrylate having an alkyl group of 1 to 8 carbon atoms. ester 0
~40 parts by weight and 0 to 10 parts by weight of other monomers copolymerizable with the above monomers are preferred. If the amount of acrylic acid alkyl ester used exceeds 40 parts by weight, the hardness and softening temperature will decrease, which is not preferable.
Other monomers may be the same as those used in the first stage (B) of the resin component described above. The acrylic resin thus obtained is recovered by spray drying or by salting out, coagulating, washing, and drying. A resin composition consisting of the acrylic resin thus obtained and the ultraviolet absorber was prepared using a melt extrusion method (T
It is made into a film by die molding, inflation molding, etc.), calendar processing method, solution casting method. The appropriate thickness of the film is 10 to 500μ. If it is less than 10μ, there will be problems in terms of the strength of the film and the protective effect of the base material, and if it exceeds 500μ, it will become expensive. Therefore, it is preferably in the range of 30 to 100μ. EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. Example 1-3, Comparative Example 1-3 A resin was obtained by a normal emulsion polymerization method using a crosslinked elastic body component and a monomer constituting the resin component having the composition shown in Table 1. First, the crosslinked elastomer component was polymerized, and the resin component monomer was continuously added and copolymerized in the presence of the crosslinked elastomer component. Thereafter, the resin used in the present invention was obtained by coagulating, washing with water, and drying by a conventional method.

[Table] The resin obtained as shown in Table 1 was kneaded and extruded using a 40 m/m extruder pelletizing device at a die temperature of 220°C to produce pellets. Incidentally, this pellet contains the ultraviolet absorber [2-(2-
hydroxy 3,5-bisγγ-dimethylbenzyl)
[Phenyl]benzotriazole was added in an amount of 1%. Using this pellet, a film was formed by inflation molding to obtain a 50μ film. Table 2 shows the physical properties of these films and the volatility of the ultraviolet absorber upon heating.

[Table] As is clear from Tables 1 and 2, the samples of the present invention have well-balanced impact strength, tensile strength, elongation, surface hardness, and softening temperature, and almost no UV absorber volatilizes at high temperatures. On the other hand, when the tensile strength of the comparative sample is high, the elongation is low;
If the elongation is large, the tensile strength and softening temperature are low, and the ultraviolet absorber volatilizes greatly, making it impossible to use it for the purpose of the present invention. Next, this film was laminated to a commercially available PVC steel plate for exterior use by heat-pressing method (200℃, 10Kg/cm ² ), and the coated steel plate was subjected to post-processing tests and weather resistance tests as shown in Table 3. . Show the results -
Shown in 3.

【table】

[Table] From the results in Table 3, it was confirmed that the acrylic film of the present invention has excellent physical properties, workability as a steel plate, and durability. Example 4, Comparative Example 4-7 Using the resin of Example 1 shown in Table 1, the UV absorber of the present invention and 2-(2-hydroxy-5-methyl-phenyl as a comparative example) were used. )
Benzotriazole, 2,2',4,4'-tetrahydroxy-benzophenone oxalic acid anilide derivative (trade name: Sandovoa VSU), ethyl-2-
For cyano-3,3-diphenol acrylate, 1 part of each of the above ultraviolet absorbers was added to 100 parts of the resin, and after blending with a Henschel mixer, pellets were made with a 40 m/m extruder pelletizing device. Film molding was carried out using the inflation molding method to obtain a 50μ film. Each film was tested for volatility after heating at 100°C for 200 hours, and for weather resistance when laminated to a PVC steel plate by heat and pressure bonding.

【table】

[Table] From this result, the film of the present invention has low high temperature volatility and small color difference and gloss change after the weather resistance test, whereas the film of the comparative example has high high temperature volatility and There are those with large color differences and changes in gloss, and those with low high-temperature volatility but large changes in color and gloss after weathering tests, both of which indicate that there are problems with durability. Example 5, Comparative Example 8 The ultraviolet absorber [2-(2-hydroxy 3,
Add 1 part of 5γγdimethylbenzyl)phenyl]benzotriazole to 100 parts of the resin, blend with a Henschel mixer, pelletize with a 40m/m extruder, and form a 30μ film from the pellets by inflation molding. , Temperature 150℃, pressure 5~10℃ on tent cloth coated with PVC sol.
It was laminated at kg/m to obtain an acrylic film laminated cloth. This was subjected to an accelerated weather resistance test using a sunshine weather meter with a water spray cycle of 12 minutes/60 minutes and a black panel temperature of 63°C, and the color difference and gloss change before and after the test were investigated. For comparison, a similar test was also conducted on a commercially available vinyl chloride laminate fabric. The results are shown in Table-5.

[Table] As shown in the above table, the acrylic film laminated with the acrylic film of the present invention shows very good results with little color difference and change in gloss. Example 6, Comparative Example 9 The composition obtained in Example 3 in Table 1 was made into a film in the same manner as in Example 5. )
It was laminated under heat and pressure at a temperature of 180℃. This sample was exposed outdoors (exposed in Osaka, facing south at 45 degrees) for two years, and the physical properties, color difference, and changes in gloss of the sample before and after exposure were measured. The results are shown in Table-6. Incidentally, as a comparative example, a sample of Comparative Example 2 was also tested.

[Table] The products of the present invention show good results with little change in physical properties, color difference, and gloss, but the comparative examples show large changes in physical properties, color difference, and gloss.

Claims (1)

[Claims] 1. The following ultraviolet absorber (X) is added to the following acrylic resin (Y ₁ ) in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the resin.
A thermoplastic acrylic resin film containing within the range of parts by weight. (X) General formula below (In the formula, R ₁ and R ₂ represent hydrogen or an alkyl group having 1 to 6 carbon atoms, and R ₃ represents hydrogen or chlorine.) (Y ₁ ) Acrylic acid alkyl ester (alkyl group) methacrylic acid alkyl ester (alkyl group having 1 to 8 carbon atoms) and 95 to 80 parts by weight of
4) A crosslinked elastomer component (A) consisting of 5 to 20 parts by weight and 0 to 10 parts by weight of another monomer copolymerizable with the above monomer, crosslinked by copolymerization of a crosslinkable monomer. Ten
In the presence of ~50 parts by weight, 10 to 60 parts by weight of an acrylic acid alkyl ester (having a carbon number of 1 to 8 in the alkyl group) and a methacrylic acid alkyl ester (having a carbon number of 1 to 8 in the alkyl group) as the first stage resin component (B). 1-4) 90
90-50 parts by weight of a monomer mixture consisting of ~40 parts by weight and 0-20 parts by weight of other monomers copolymerizable with the above monomers
Acrylic resin made by adding and copolymerizing parts by weight. 2 The ultraviolet absorber (X) has the following general formula A film according to claim 1, which is represented by: 3. The film according to claim 1 or 2, wherein the film has a thickness of 10 to 300μ. 4 Add the following ultraviolet absorber (X) to the following acrylic resin (Y ₂ ) in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the resin.
A thermoplastic acrylic resin film containing within the range of parts by weight. (X) General formula below (In the formula, R ₁ and R ₂ represent hydrogen or an alkyl group having 1 to 6 carbon atoms, _and R ₃ represents hydrogen or chlorine.) methacrylic acid alkyl ester (alkyl group having 1 to 8 carbon atoms) and 95 to 80 parts by weight of
4) A crosslinked elastomer component (A) consisting of 5 to 20 parts by weight and 0 to 10 parts by weight of another monomer copolymerizable with the above monomer, crosslinked by copolymerization of a crosslinkable monomer. Ten
In the presence of ~50 parts by weight, 10 to 60 parts by weight of an acrylic acid alkyl ester (having a carbon number of 1 to 8 in the alkyl group) and a methacrylic acid alkyl ester (having a carbon number of 1 to 8 in the alkyl group) as the first stage resin component (B). 1-4) 90
90-50 parts by weight of a monomer mixture consisting of ~40 parts by weight and 0-20 parts by weight of other monomers copolymerizable with the above monomers
Part by weight is added and copolymerized, and the second stage of resin component (C) is further added.
100 to 60 parts by weight of methacrylic acid alkyl ester (alkyl group having 1 to 4 carbon atoms) and acrylic acid alkyl ester (alkyl group having 1 to 4 carbon atoms)
8) Monomer mixture consisting of 0 to 40 parts by weight and 0 to 10 parts by weight of other monomers copolymerizable with the above monomers.
A thermoplastic acrylic resin film made by adding and copolymerizing 50 to 100 parts by weight. 5 The ultraviolet absorber (X) has the following general formula The film according to claim 4, which is represented by: 6. The film according to claim 4 or 5, wherein the film has a thickness of 10 to 300μ.