JP3263796B2 - Resin molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention
The present invention relates to a molded article made of a polyester-based resin which is prevented from disappearing.

[0002]

2. Description of the Related Art Polyester resins are excellent in strength and the like, but have a drawback of poor weather resistance. Therefore, when manufacturing a roofing material or other exterior building materials by melting and molding a polyester resin such as polycarbonate, an ultraviolet absorber is added to the resin to suppress deterioration of the resin due to ultraviolet rays and improve weather resistance. Is being planned.

[0003]

However, even if a conventionally used ultraviolet absorber is added to a polyester resin such as polycarbonate, the ultraviolet absorber is easily volatilized and disappears during melting and molding of the resin. There is a problem that it is gradually volatilized and disappears even after molding. Therefore, the conventional polyester resin molded article containing the ultraviolet absorbent is still unsatisfactory in that the weather resistance is maintained for a long time.

[0004] Under these circumstances, recently, research has been conducted on high-molecular-weight ultraviolet absorbers that are difficult to volatilize, and for example, ultraviolet absorbers made of a copolymer of a benzophenone-based compound and an acrylic monomer have been developed. However, such a high molecular weight ultraviolet absorber may have poor compatibility with the polyester resin, and when added to a polycarbonate resin or the like having a good transparency, a problem of a decrease in transparency or a problem of coloring occurs. There are cases.

In some cases, a heat resistance improver, a flame retardant, and other additives are added to the polyester resin molded article depending on the application. However, there is a problem that it is difficult to maintain the performance of the additive for a long period of time because of volatilization over time.

The present invention has been made in view of the above problems, and has as its object to maintain the performance of an ultraviolet absorber for a long period of time without almost asking for volatilization or disappearance of the ultraviolet absorber. An object of the present invention is to provide a polyester resin molded article which can be used and can save the amount of the ultraviolet absorber used.

[0007]

Means for Solving the Problems In order to achieve the above object, a resin molded product of the present invention is characterized in that 2- (2'-hydroxy-
5'-carboxyphenyl) benzotriazole, 2-
Hydroxybenzophenone-4-oxyacetic acid, 2-hydroxy-4- (2'-hydroxyethoxy) benzophenone, 2,2 ', 4,4', 6,6'-hexahydroxybenzophenone, 2- (2 ', 4' -Dihydroxyphenyl) benzotriazole, 2-hydroxy-4-
(2'-hydroxyethoxy) benzotriazole, 2
-Hydroxy-5- (2'-hydroxyethyl) benzotriazole, 2- (2'-hydroxy-3'-amino-5'-t-butyl) benzotriazole, 2-hydroxy-4- (2'-methacryloyloxy Ethoxy) benzophenone, 2,4-di-t-butylphenyl-
(3 ', 5'-di-t-butyl-4'-hydroxy) benzophenone, methyl 2-hydroxybenzophenone-4-oxyacetate, 2- (2'-acryloyloxy-
Any of the ultraviolet absorbers of 5'-methyl) benzotriazole is subjected to a transesterification reaction with the polymer molecules of the polyester-based resin to form an ester bond to form a polyester-based resin surface layer containing the unreacted ultraviolet absorber. Characterized in that it is laminated on the surface of the polyester resin base layer to which the ultraviolet absorbent has not been added.

[0008]

The ultraviolet absorber used in the present invention is a compound having a carboxyl group, a hydroxyl group, or an amino group at the molecular terminal or a compound having an ester bond in the molecule. Before the resin molded article of the present invention is formed by the method, when the ultraviolet absorber is added to a polyester resin for forming a surface layer, most of the ultraviolet absorber is formed of polymer molecules of the polyester resin in a heat-melted state. A transesterification reaction occurs at the ester bond portion, the ultraviolet absorber is immobilized by ester bond, and the unreacted ultraviolet absorber is contained in a dispersed state between polymer molecules. Therefore, in the resin molded article of the present invention, the above-mentioned ester-bonded ultraviolet absorbent is retained in the polyester-based resin surface layer without volatilization, so that the ultraviolet absorbent can be maintained for a long period of time. Since the above-mentioned ultraviolet absorber is not added to the polyester resin base layer, the amount of the ultraviolet absorber used can be reduced.

[0009]

Embodiments of the present invention will be described below.

The resin molded article of the present invention is a molded article having a two-layer or three-layer structure in which a polyester resin surface layer is laminated on an upper surface or both upper and lower surfaces of a polyester resin base layer,
Polyester resin surface layer is a carboxyl group, hydroxyl group, UV absorber having any of amino group at the molecular end,
Alternatively, it is a layer in which the ultraviolet absorber having an ester bond in the molecule is transesterified with the polymer molecule of the polyester-based resin to form an ester bond and contains the unreacted ultraviolet absorber.

As the polyester resin as a raw material, thermoplastic polyester resins such as polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyarylate, and polycaprolactone, which have a relatively high melting temperature and easily cause a transesterification reaction, are preferably used. You.

On the other hand, the ultraviolet absorber used in the present invention has one of a carboxyl group, a hydroxyl group, and an amino group at the molecular terminal, or has an ester bond in the molecule. Any of the UV absorbers shown may be used. That is, 2- (2'-hydroxy-5'-carboxyphenyl) benzotriazole and 2-hydroxybenzophenone-4-oxyacetic acid are used as the ultraviolet absorber having a carboxyl group at the molecular terminal, and a hydroxyl group is added at the molecular terminal. As the ultraviolet absorber, 2-hydroxy-4- (2'-hydroxyethoxy) benzophenone, 2,2 ', 4,4', 6,6'-hexahydroxybenzophenone, 2- (2 ', 4'- Dihydroxyphenyl) benzotriazole, 2-hydroxy-4-
(2'-hydroxyethoxy) benzotriazole, 2
-Hydroxy-5- (2'-hydroxyethyl) benzotriazole is used, and as an ultraviolet absorber having an amino group at a molecular terminal, 2- (2'-hydroxy-3'-
Amino-5'-t-butyl) benzotriazole is used, and as a UV absorber having an ester bond in the molecule, 2-hydroxy-4- (2'-methacryloyloxyethoxy) benzophenone, 2,4-di- t-butylphenyl- (3 ', 5'-di-t-butyl-4'-hydroxy) benzophenone, methyl 2-hydroxybenzophenone-4-oxyacetate, 2- (2'-acryloyloxy-5'-methyl) Benzotriazole is used.

These ultraviolet absorbers are used in an amount of 0.01 to 10.0 parts by weight based on 100 parts by weight of the polyester resin in the surface layer.
It is desirable to add in parts by weight. When the compounding amount of the ultraviolet absorber is less than 0.01 part by weight, it is difficult to impart excellent ultraviolet absorbing ability, and when it is more than 10.0 parts by weight, the molecular weight of the polymer is reduced, Due to coloring, the commercial value decreases. When these ultraviolet absorbers are used in combination with an ultraviolet absorber having neither a carboxyl group, a hydroxyl group, nor an amino group at a molecular end, or an ultraviolet absorber having no ester bond in a molecule, the coloring property is improved. Can be.

[0014]

Before the resin molded article of the present invention is formed by a method such as co-extrusion molding, the above-mentioned ultraviolet absorber (hereinafter sometimes simply referred to as an additive) is added to a polyester resin for forming a surface layer. Most of the additives cause a transesterification reaction at the ester-bonded portion in the polymer molecule of the polyester-based resin to produce a polymer molecule in which the additive is ester-bonded to the molecular terminal. The unreacted additives are contained in a dispersed state between the polymer molecules.

Therefore, in the polyester resin molded article of the present invention having a two-layer or three-layer structure obtained by co-extrusion molding, the additive is immobilized by ester bonding to the terminal of the polymer molecule of the polyester resin in the surface layer. Since it is contained and held in the surface layer without volatilization, the action of the additive can be maintained for a long period of time. The unreacted additives volatilize and disappear over time, but the amount is small.

The transesterification reaction between the polyester resin and the additive occurs when the polyester resin is heated to a temperature not lower than the melting temperature and not higher than the decomposition temperature to be in a molten state before the coextrusion molding. Therefore, when a polycarbonate resin is used as the polyester resin, for example, it may be heated to a temperature of about 230 to 330 ° C. and melted inside the co-extrusion molding machine.

Additives having a carboxyl group, a hydroxyl group or an amino group at the terminal of the molecule are highly reactive, and some can cause transesterification without a catalyst. If there is no such compound, a transesterification reaction will not occur. Therefore, when such an inferior additive is used, it is necessary to add a catalyst. Examples of the catalyst include an alkali metal carbonate (eg, potassium carbonate), an alkali metal bicarbonate (eg, sodium hydrogen carbonate), an alkali metal oxide (eg, sodium oxide), and an alkali metal hydroxide (eg, sodium hydroxide). ), Alkali metal carboxylate (eg, sodium acetate), alkali metal alkoxide (eg, sodium tomexide), alkaline earth metal carbonate (eg, calcium carbonate), alkaline earth metal oxide (eg, calcium oxide) Alkaline earth metal hydroxide (eg, calcium hydroxide), alkaline earth metal carboxylate (eg, calcium acetate), alkaline earth metal alkoxide (eg, magnesium methoxide), transition metal oxide (eg, Antimony trioxide), a transition metal halide (eg, Iron), a transition metal alkoxide (e.g. tetraethoxy titanium), inorganic acids (e.g. sulfuric acid),
A catalyst for transesterification such as sulfonic acid (for example, p-toluenesulfonic acid) is used. These catalysts are suitably added at a ratio of 0.001 to 0.5 part by weight based on 100 parts by weight of the polyester resin in the surface layer.

In general, the rate of transesterification is highest for an additive having a hydroxyl group, then for an additive having an amino group, an additive having a carboxyl group, and then an additive having an ester bond. The reaction speed also varies depending on the type of resin. Therefore, the time required for the transesterification reaction varies slightly depending on the type of the reactive group of the additive and the type of the polyester resin, but in any case, the reaction is almost completed in about 1 to 15 minutes. Therefore, when co-extrusion molding the resin molded product of the present invention, the above-mentioned additives are added to the molten polyester resin for forming the surface layer in the co-extrusion molding machine, and the mixture is kneaded for about 1 to 15 minutes. It is important to superimpose on a molten polyester-based resin for forming a base layer and extrude it so that the transesterification reaction is sufficiently performed.

The resin molded product of the present invention can be formed into various shapes such as plates, sheets, films, and irregularly shaped products having a two-layer or three-layer structure.

Next, a description will be given of a test performed to confirm the effect when the additive is ester-bonded to the polymer molecule of the polyester resin.

[Test 1] Polycarbonate as a polyester resin and 2-hydroxy-4- (2-methacryloyloxyethoxy) benzophenone as an ultraviolet absorber were used as polycarbonate 1.
Dry blending was performed in advance with a mixing ratio of 1.0 part by weight to 00 parts by weight and 0.02 part by weight of disodium maleate as a catalyst. This blend is put into an extruder, heated at 270 ° C., melt-kneaded, transesterified for about 10 minutes, and extruded from a mold of the extruder to form a 0.1 mm thick film. I got Then, a test piece (1) was prepared from this film.

With respect to this test piece (1), the quantitative ratio (reaction rate) of the ultraviolet absorber which had been ester-bonded and the ultraviolet absorber which had remained unreacted was determined by the test method described below. It was found that the UV absorber had a transesterification reaction at a reaction rate of about 50%.

Further, the test piece (1) was subjected to an accelerated weather resistance test to examine the relationship between the irradiation time, the yellowing degree (ΔYI), and the residual ratio of the ultraviolet absorbent. The results are shown in Table 1 below. The accelerated weathering test was carried out using a xenon weatherometer (manufactured by Atlas) for 100 hours and 500 hours.
An acceleration test was conducted by irradiation at r and 1000 hr, and ΔYI was determined by measuring with a # 90 color measuring system (manufactured by Nippon Denshoku Co., Ltd.). Also, the survival rate is
Using a visible ultraviolet spectrophotometer UV-3100 (manufactured by Shimadzu Corporation), the ultraviolet absorbance of the test piece at each irradiation time was measured, and the change in absorbance at the maximum absorption wavelength of the ultraviolet absorber at the irradiation time of 0 hr was measured. This is a value calculated by setting the residual rate to 100.

(Test Method of Reaction Rate) The reaction rate is confirmed using a GPC (gel permeation chromatography) apparatus. The maximum ultraviolet absorption wavelength (λ) of the ultraviolet absorber 2-hydroxy-4- (2-methacryloyloxyethoxy) benzophenone used in Test 1
max) is 325 nm. Therefore, the detection wavelength of the GPC ultraviolet detector is adjusted to 325 nm, which is not detected at the measurement sample concentration for the polycarbonate and the catalyst blended together with the ultraviolet absorber. For comparison, a blend in which the solvents were mixed at the same compounding ratio and did not undergo transesterification was used as a comparative example. The molecular weight distribution curve of the GPC of this comparative example is as shown in FIG. 1, and the peak (a) of the ultraviolet absorbent appears on the low molecular weight side (right side of the horizontal axis). On the other hand, the molecular weight distribution curve of the GPC of the test piece (1) prepared in Test 1 is as shown in FIG. 2, and the peak (b) is the peak of the ultraviolet absorbent observed when no transesterification reaction was performed. It appears at the same elution time as (a), but the detection intensity is low, and the attenuated peak (b) is on the polymer side (left side of the horizontal axis)
And shifts to the peak (c). That is, the reaction between the ultraviolet absorber and the terminal of the polycarbonate causes the ultraviolet absorber to have a high molecular weight and shifts the peak. (C)
Indicates the peak of the reacted portion, and (b) indicates the peak of the unreacted portion. The reaction rate is determined from the area ratio between the peak (b) and the peak (c) in the molecular weight distribution curve. Next, the test piece (1) prepared in Test 1 was purified to remove the unreacted ultraviolet absorber, and
It is confirmed by -IR and 1H, 13C-NMR that the ultraviolet absorber is ester-bonded to the terminal. From this, it can be confirmed that the peak (c) is not homopolymerization of only the ultraviolet absorber.

[Test 2] Polycarbonate as a polyester resin, 2- (2'-hydroxy-5'-carboxyphenyl) benzotriazole (λmax = 325 nm) as an ultraviolet absorber
0.8 parts by weight with respect to 100 parts by weight of polycarbonate, and triphenylphosphite as a catalyst was 0.08 part by weight.
A test piece (2) was prepared in the same manner as in Test 1, except that dry blending was performed in advance in a blending ratio of parts by weight.

When the reaction rate of the ultraviolet absorber of this test piece (2) was determined by the above-mentioned test method, it was found that the ester exchange reaction of the ultraviolet absorber was at a reaction rate of about 37%. Further, this test piece (2) was subjected to an accelerated weathering test in the same manner as in Test 1, and the irradiation time and the yellowing degree (ΔY
I), the relationship with the residual ratio of the ultraviolet absorber was examined. The results are shown in Table 1 below.

[Test 3] Polycarbonate as polyester resin and 2- (2 ', 4'-dihydroxyphenyl) as ultraviolet absorber
The same procedure as in Test 1 was carried out except that benzotriazole (λmax = 344 nm) was dry-blended in advance at a blending ratio of 1.2 parts by weight to 100 parts by weight of polycarbonate and 0.05 part by weight of phenylphosphonic acid as a catalyst. To prepare a test piece (3).

With respect to this test piece (3), the reaction rate of the ultraviolet absorbent was determined by the above-mentioned test method (however, the wavelength of the ultraviolet ray detector of GPC was 344 nm). Was found to be transesterified. Further, an accelerated weather resistance test was performed on this test piece (3) in the same manner as in Test 1, and the relationship between the irradiation time, the yellowing degree (ΔYI), and the residual ratio of the ultraviolet absorbent was examined. The results are shown in Table 1 below.

[Test 4] Polycarbonate as a polyester resin and 2-hydroxy-4- (2'-hydroxyethoxy) benzophenone (λmax = 330 nm) as an ultraviolet absorber in an amount of 1.1 parts by weight based on 100 parts by weight of the polycarbonate. Test piece (4) was prepared in the same manner as in Test 1, except that dry blending was performed in advance at the mixing ratio.

With respect to this test piece (4), the reaction rate of the ultraviolet absorbent was determined by the above-mentioned test method (however, the wavelength of the ultraviolet detector of GPC was 330 nm). Was found to be transesterified. Further, the test piece (4) was subjected to an accelerated weather resistance test in the same manner as in Test 1, and the relationship between the irradiation time, the yellowing degree (ΔYI), and the residual ratio of the ultraviolet absorbent was examined. The results are shown in Table 1 below.

[Test 5] Polycarbonate as a polyester resin and 2- (2'-hydroxy-5'-carboxyphenyl) benzotriazole (λmax = 325 nm) as an ultraviolet absorber
Test 1 except that dry blending was previously performed at a blending ratio of 1.0 part by weight to 100 parts by weight of polycarbonate.
A test piece (5) was prepared in the same manner as described above.

When the reaction rate of the ultraviolet absorbent of this test piece (5) was determined by the above-described test method, it was found that the transesterification of the ultraviolet absorbent occurred at a reaction rate of about 18%. Further, this test piece (5) was subjected to an accelerated weathering test in the same manner as in Test 1, and the irradiation time and the yellowing degree (ΔY
I), the relationship with the residual ratio of the ultraviolet absorber was examined. The results are shown in Table 1 below.

[Comparative Test] A comparative test piece (thickness: 1.0 part by weight of an ultraviolet absorber 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole mixed with 100 parts by weight of polycarbonate) 0.1 mm), an accelerated weathering test was performed in the same manner as in Test 1, and the relationship between the irradiation time, the yellowing degree (ΔYI), and the residual ratio of the ultraviolet absorbent was examined. The results are shown in Table 1 below.

[0035]

[Table 1]

It can be seen from Table 1 that the comparative test piece in which the ultraviolet absorbent is simply mixed has a residual rate of the ultraviolet absorbent of up to 69% after irradiation for 1000 hours because the ultraviolet absorbent is easily volatilized with time. Test pieces (1) to (5), in which most of the UV absorber was ester-bonded to a polycarbonate polymer, whereas the degree of yellowing increased to Since the ester-bound ultraviolet absorber is fixed and the unreacted ultraviolet absorber only volatilizes with time, the residual ratio of the ultraviolet absorber after irradiation for 1,000 hours is as high as 84% even at the lowest, and yellowing The maximum value was 1.9, which is less than half the value of the comparative test piece, which indicates that excellent weather resistance is maintained.

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

As is clear from the above description and the test results, in the resin molded article of the present invention, most of the ultraviolet absorber is immobilized by ester bonding to the polymer molecules of the polyester resin surface layer. Has a remarkable effect that it hardly volatilizes over time and can maintain the ultraviolet absorbing effect for a long period of time. Further, since no ultraviolet absorbing agent is added to the polyester resin base layer, the amount of the ultraviolet absorbing agent used It also has the effect of saving money.

[Brief description of the drawings]

FIG. 1 is a molecular weight distribution curve of a comparative blend by GPC.

FIG. 2 is a molecular weight distribution curve of the test piece (1) measured by GPC.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08K 5/05 C08K 5/05 5/09 5/09 5/17 5/17 C08L 67/02 C08L 67/02 // B29C 47 / 10 B29C 47/10 C09K 3/00 104 C09K 3/00 104A 104C B29K 67:00 B29K 67:00 (72) Inventor Yoichiro Makimura 2-3-13 Azuchicho, Chuo-ku, Osaka City Inside Takiron Co., Ltd. 72) Inventor Hirofumi Takase 2-3-13 Azuchi-cho, Chuo-ku, Osaka City Inside Takiron Co., Ltd. (56) References JP-A-60-165244 (JP, A) JP-A-49-99596 (JP, A) JP-A-1-201330 (JP, A) JP-A-2-188581 (JP, A) JP-A-3-200788 (JP, A) JP-A-4-5291 (JP, A) JP-A-4-103626 (JP, A) Special Table Hei 4-507419 (JP A) (58) investigated the field (Int.Cl. ^7, DB name) C08J 5/00 B32B 27/36 C08G 63/91 C08L 67/02

Claims (1)

(57) [Claims] 1. 2- (2'-hydroxy-5'-carboxyphenyl) benzotriazole, 2-hydroxybenzophenone-4-oxyacetic acid, 2-hydroxy-4-
(2'-hydroxyethoxy) benzophenone, 2,
2 ', 4,4', 6,6'-hexahydroxybenzophenone, 2- (2 ', 4'-dihydroxyphenyl) benzotriazole, 2-hydroxy-4- (2'-hydroxyethoxy) benzotriazole, 2- Hydroxy-5- (2'-hydroxyethyl) benzotriazole, 2- (2'-hydroxy-3'-amino-5'-t
-Butyl) benzotriazole, 2-hydroxy-4-
(2'-methacryloyloxyethoxy) benzophenone, 2,4-di-t-butylphenyl- (3 ', 5'-
Di-tert-butyl-4'-hydroxy) benzophenone,
Methyl 2-hydroxybenzophenone-4-oxyacetate, 2- (2'-acryloyloxy-5'-methyl)
Any one of the benzotriazole ultraviolet absorbers undergoes transesterification with the polymer molecules of the polyester-based resin to form an ester bond, and the polyester-based resin surface layer containing the unreacted ultraviolet-absorber is coated with the ultraviolet-absorber. A resin molded product characterized by being laminated on the surface of a polyester resin base layer to which no is added.