JP3371992B2 - Polycarbonate coextrusion product and its coextrusion method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarbonate coextrusion product excellent in water resistance, weather resistance, molding processability and thermal stability, and a coextrusion method thereof.

[0002]

2. Description of the Related Art Polycarbonate resin is excellent in transparency, impact resistance, heat resistance, etc.
Widely used for road materials, automobile parts, etc.,
It is inferior in weather resistance to acrylic resin, which is a transparent material, and has various restrictions in its field of use, particularly in the field of use outdoors.

A method of co-extruding an acrylic resin with a polycarbonate resin (Japanese Patent Publication No. 47-19119 and Japanese Patent Laid-Open No. 5559929) has been already proposed. However, the impact resistance of such a co-extruded sheet is remarkably lowered, and both resins are Since the refractive index of the coextrusion sheet is different, there is a problem that the transparency is lost when the ears of the coextrusion sheet are recycled.

On the other hand, by co-extruding a polycarbonate resin composition containing an ultraviolet absorber and a polycarbonate resin, a co-extruded sheet capable of preventing a decrease in impact resistance and allowing recycling (Japanese Patent Laid-Open No. 55-5992).
9, JP-A-59-101360), and a compound of a specific dicyano compound (US Pat. No. 4,264,680) is newly proposed.

However, since they are inferior in water resistance and unsatisfactory in weather resistance, they are still subject to many restrictions when used in the outdoor field. In addition, it has a problem that it is inferior in moldability and heat stability. Further, in many cases, it is a problem in the use of a coextruded product which is inferior in initial colorability and requires high transparency.

[0006]

Therefore, a polycarbonate resin which has excellent water resistance and weather resistance as well as excellent moldability and heat stability and can be used even in the outdoor field, and which has no initial coloration is used. The development of extruded products and their coextrusion methods has been desired. In recent years, it has been desired to develop recyclable products from the viewpoint of resource reuse.

[0007]

DISCLOSURE OF THE INVENTION As a result of earnest research in view of the above-mentioned problems, the present inventor has found that on a substrate of a polycarbonate composition containing two specific compounds in specific amounts, and Polycarbonate co-extruded product having a skin layer of a polycarbonate composition containing a specific amount of two compounds and a specific ultraviolet absorber has excellent water resistance, weather resistance, molding processability and thermal stability. That is, the present invention has been achieved. Furthermore, the polycarbonate coextrusion product of the present invention does not significantly deteriorate the original properties of the polycarbonate even when used as a recycled product, and thus can be recycled.

That is, the present invention is a polycarbonate resin containing 0.01 to 0.5% by weight of a phosphorus compound represented by the following general formula (1) and 0.005 to 0.1% by weight of a phenolic compound. From the composition (A) as a matrix, a phosphorus compound represented by the following general formula (1): 0.01 to
0.5% by weight, phenolic compound 0.005-0.1
Excellent water resistance, weather resistance, molding processability, and heat stability, which comprises as a surface layer a polycarbonate resin composition (B) containing 1.0 to 15% by weight of a benzotriazole-based UV absorber having a molecular weight of 380 or more by weight. The present invention provides a polycarbonate coextrusion product having properties and a coextrusion method thereof.

[0009]

Embedded image General formula (1)

[ _One of R ₁ and R ₂ is an alkyl group having 1 to 4 carbon atoms and the other is hydrogen, or both are alkyl groups having 1 to 4 carbon atoms]

The present invention will be described in detail below. In the present invention, the polycarbonate resin used as the base material (A) and the surface layer (B) means a phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene, or an ester in which a dihydroxydiaryl compound is reacted with a carbonic acid ester such as diphenyl carbonate. A polymer obtained by the exchange method, and a typical one is 2,2
A polycarbonate produced from bis (4-hydroxyphenyl) propane (bisphenol A).

Examples of the dihydroxydiaryl compound include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, and 2,2-bis (4-hydroxyphenyl), in addition to bisphenol A.
Butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4 -Hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane,
2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,
Bis (hydroxyaryl) alkanes such as 5-dichlorophenyl) propane, bis (hydroxyaryl) such as 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane Cycloalkanes, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-
Dihydroxy diaryl ethers such as 3,3′-dimethyldiphenyl ether, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3,
Dihydroxydiaryl sulfides such as 3'-dimethyldiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-
Examples include dihydroxydiaryl sulfoxides such as 3,3′-dimethyldiphenyl sulfoxide, 4,4′-dihydroxydiphenyl sulfone, and dihydroxydiaryl sulfones such as 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone. To be

These may be used alone or in admixture of two or more, but in addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl and the like may be mixed and used.

Further, the above-mentioned dihydroxyaryl compound and a phenol compound having a valence of 3 or more as shown below may be mixed and used.

Examples of trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene-2,4,6-dimethyl-2,4,6-tri. -(4-Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4,4-
(4,4′-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

The viscosity average molecular weight of the polycarbonate resin is usually 10,000 to 100,000, preferably 15,
It is 000-35,000. In producing such a polycarbonate resin, a molecular weight modifier, a catalyst and the like can be used if necessary.

The phosphorus compound used in the present invention is a compound represented by the following general formula (1).

[0018]

Embedded image General formula (1)

[ _One of R ₁ and R ₂ is an alkyl group having 1 to 4 carbon atoms and the other is hydrogen, or both are alkyl groups having 1 to 4 carbon atoms]

Specifically, for example, tris (nonylphenyl) phosphite, triphenylphosphite, tris (ethylphenyl) phosphite, tris (butylphenyl) phosphato, tris (hydroxyphenyl) phosphite, tetrakis (2,4) Examples of phosphite-based compounds such as -di-t-butylphenyl) -4,4'-biphenylene diphosphite and tris (2,4-di-t-butylphenyl) phosphite include one kind or two or more kinds. Can be used. Particularly, tris (2,4-di-t-butylphenyl) phosphite is preferable.

The phosphorus compound represented by the general formula (1) is
0. It is blended in an amount of 01 to 0.5 % by weight. If it is less than 0.01 % by weight, the effect of preventing yellowing during granulation and molding is insufficient. Further, if it exceeds 0.5 % by weight, the water resistance is significantly lowered. It is particularly preferably 0.05 to 0.3 % by weight.

As a phenolic compound used together with such a phosphorus compound, octadecyl-3- (3'-
5'-di-t-butyl-4-hydroxyphenyl) propionate, tetrakismethylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane,
2,2-thio [diethylbis-3 (3,5-di-t-butyl-4-hydroxyphenyl) propionate],
2,6-di-t-butyl-4-methylphenol, 2-
t-butyl-6- (3-t-butyl-2-hydroxy-
5-Methylbenzyl) -4-methylphenyl acrylate, alkylated bisphenol, 4,4′-butylidene bis (3-methyl-6-t-butylphenol) and the like are exemplified, and one or more kinds can be used. From the viewpoint of preventing yellowing during granulation, the compound represented by the following general formula (2) or (3), that is, 2,2-thio [diethylbis-3 (3,5-di-t-butyl-4-hydroxy) is used. Phenyl) propionate or octadecyl-3- (3'-5'-di-t-butyl-4-hydroxyphenyl) propionate are preferred.

[0023]

Embedded image General formula (2)

[R _{1 to} R ₄ are alkyl groups having 1 to 4 carbon atoms, n is 1 to 3]

[0025]

Embedded image General formula (3)

[R ₁ and R ₂ are alkyl groups having 1 to 4 carbon atoms, R ₃ is an alkyl group having 1 to 30 carbon atoms, and n is
1-10]

The phenolic compound is 0. 005-0.
1 % by weight is blended. If it is less than 0.005 % by weight, the effect of preventing yellowing during granulation molding is poor. On the other hand, when it exceeds 0.1 % by weight , the water resistance is remarkably lowered , and the yellowing due to the coloring of the phenolic compound itself is large, which is not suitable for practical use. It is particularly preferably 0.01 to 0.08 % by weight.

There are no particular restrictions on the timing and method of blending the phosphorus compound and the phenol compound,
It may be carried out during or after the polymerization of the polycarbonate resin, and further, it can be carried out by mixing with a powder, pellet or beaded polycarbonate resin in a known mixer such as a tumbler, a ribbon blender, a high speed mixer and the like, and melt kneading. It is not necessary to add the phosphorus compound and the phenol compound at the same time,
It can be blended at any time or in any order.

Next, the ultraviolet absorber used in the present invention is a benzotriazole type ultraviolet absorber having a molecular weight of 380 or more. With a benzotriazole-based UV absorber having a molecular weight of less than 380, the viscosity of the polycarbonate resin composition decreases during film processing, and a film having a uniform thickness cannot be obtained. Preferably 380-70
It is 0.

Further, even among ultraviolet absorbers having a molecular weight of 380 or more, compounds other than benzotriazole type ultraviolet absorbers such as benzophenone type and hindered amine type ultraviolet absorbers are inferior in the effect of improving the weather resistance.

As the benzotriazole type ultraviolet absorber having a molecular weight of 380 or more, 2,2-methylene-bis- [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzo having a molecular weight of 659 is used. Triazol-2-yl) phenol], 2- [2-hydroxy- having a molecular weight of 447]
3,5-bis (α, α-dimethylbenzyl) phenyl]
-2H-benzotriazole, 2- [2 having a molecular weight of 388
-Hydroxy-3 '-(3', 4 ', 5', 6'-tetra-hydrophthalimido-methyl) -5'-methylphenyl] benzotriazole, methyl-3- [3-t-butyl-5- ( 2H-benzotriazol-2-yl)-
4-hydroxyphenyl] propionate-polyethylene glycol is exemplified, and one kind or two or more kinds can be used.

Particularly, 2- [2-hydroxy-3'- having a molecular weight of 388 as a benzotriazole type ultraviolet absorber.
By using (3 ', 4', 5 ', 6'-tetra-hydrophthalimido-methyl) -5'-methylphenyl] benzotriazole, a polycarbonate coextruded product having no initial coloration and excellent transparency is obtained. be able to.

The benzotriazole type ultraviolet absorber having a molecular weight of 380 or more is contained in the polycarbonate resin composition constituting the surface layer in an amount of 1 to 15 % by weight. If it is less than 1% by weight, the weather resistance is poor, and if it exceeds 15 % by weight, the processing of the surface layer portion becomes difficult. From the viewpoint of weather resistance and processability, a polycarbonate resin composition containing 3 to 15% by weight of an ultraviolet absorber is preferable.

There is no particular limitation on the timing and method of blending the above-mentioned ultraviolet absorber, and it may be during or after the polymerization of the polycarbonate resin, and powder,
It can be carried out by mixing with a pellet or bead-shaped polycarbonate resin in a known mixer, for example, a tumbler, a ribbon blender, a high speed mixer, etc., and melt kneading.

Examples of the co-extrusion method include a method of sticking sheets and / or films extruded from two or more extruders by a roll, a method of co-extruding with a single extrusion die using a multi-flow nozzle, and the like. To be

Thickness of a base material comprising a polycarbonate resin composition (A) containing a phosphorus compound and a phenol compound and a polycarbonate resin composition (B) containing a phosphorus compound, a phenol compound and an ultraviolet absorber.
The thickness of the surface layer portion composed of is not particularly limited, but the thickness of the surface layer portion is preferably 0.01 mm to 1 mm, particularly preferably 0.02 mm to 0.1 mm.

Known additives such as colorants, antioxidants, heat stabilizers, antistatic agents, lubricants, release agents and flame retardants can be added to the base material portion and the surface layer portion. Also,
It is also possible to add an ultraviolet absorber other than the ultraviolet absorber which is essential in the present invention, as long as the object of the present invention is not impaired.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, "part" and "%" are based on a weight basis.

Examples 1 to 8 and Comparative Examples 1 to 6 Polycarbonate resins (viscosity average molecular weight 24,000 or 27,000) were blended with various compounds to obtain polycarbonate resin compositions. The compounding ratios are shown in Tables 1 and 2. The polycarbonate resin composition thus obtained is coextruded into three layers by using an extrusion die having a multi-flow nozzle, and various coextrusion sheets having a surface layer of the ultraviolet absorbent-containing polycarbonate resin composition on both surfaces (3 mm thick sheet in total). Got Extrusion temperature: 280 ° C. Base material thickness: 2.9 mm Surface layer thickness: 0.05 mm Each of the obtained coextruded sheets was evaluated for performance, and the results are shown in Table 3. The compounds used and the evaluation method are shown below.

Phosphorus compounds: tris (2,4-di-t-butylphenyl) phosphite; tetrakis (2,4-di-t-butylphenyl)
4,4'-bisphenyldiphosphonite

Phenolic compound; 2,2-thio [diethylbis-3 (3,5-di-
t-butyl-4-hydroxyphenyl) propionate

UV absorber; 2,2-methylene-bis- [4-having a molecular weight of 659
(1,1,3,3-tetramethylbutyl) -6- (2H
-Benzotriazol-2-yl) phenol]; 2- [2-hydroxy-3,5-having a molecular weight of 447]
Bis (α, α-dimethylbenzyl) phenyl] -2H-
Benzotriazole; 2- [2-hydroxy-3'- having a molecular weight of 388
(3 ′, 4 ′, 5 ′, 6′-Tetra-hydrophthalimido-methyl) -5′-methylphenyl] benzotriazole; 2- (2′-hydroxy-5′- having a molecular weight of 321)
t-octylphenyl) benzotriazole

The cloud value of the test plate cut out from the water-resistant coextrusion sheet was measured by AS
It measured based on TM D1003. In addition, the same test plate is used for the pressure cooker (Tabay Seisakusho T
After treating with PC-411) for 50 hours under the condition of 125 ° C. and relative humidity of 99%, the haze value was measured by the same method as above, and the increase value (ΔHZ) was calculated. The smaller ΔHZ is, the more excellent the water resistance is.

The YI of the test plate cut out from the heat stable coextrusion sheet was measured by AS
It was measured according to TM D1925. The sheet was processed for 800 hours at 140 ° C. using a gear oven (Tabay Seisakusho), and then YI was processed by the same method as above.
Was measured and the increase value (ΔYI) was calculated.

Molding Stability It was judged whether or not the appearance of the sheet surface would be impaired to a practical problem due to roll contamination and roll adhesion during coextrusion molding.

Yellow test plates cut out from weathering coextruded sheets
Wness Index was measured according to ASTM D1925. After irradiating the sheet with a sunshine weather meter for 2000 hours, the Yellowness Index was measured by the same method as above, and the increase value (ΔYI) was calculated. The smaller ΔYI is, the more excellent the weather resistance is.

The total light transmittance of the test plate cut out from the co-extruded sheet having the initial colorability is ASTM D-1003 and Yellow I.
The index was measured according to ASTM D-1925. The higher the total light transmittance, the more yellow in
The lower the dex, the more excellent the initial colorability.

[0048]

[Table 1] Table 1 Surface layer composition

[0049]

[Table 2]

[0050]

[Table 3]

[0051]

INDUSTRIAL APPLICABILITY The polycarbonate coextrusion product of the present invention has thermal stability (ΔYI) as compared with conventionally known coextrusion products.
In addition, it is remarkably excellent in water resistance (ΔHZ), which makes it possible to develop new applications such as terraces made of polycarbonate coextrusion products, building materials such as greenhouses, outdoor parts such as automobile parts such as sunroofs, and food fields. Furthermore, it enables recycling of polycarbonate coextrusion products.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C08K 5/23 C08K 5/23 5/524 5/524 C08L 69/00 C08L 69/00 (56) Reference JP-A 1- 165419 (JP, A) JP 2-11323 (JP, A) JP 2-59341 (JP, A) JP 4-28716 (JP, A) JP 4-159354 (JP, A) JP-A-4-36346 (JP, A) JP-A-6-64123 (JP, A) JP-A-6-166808 (JP, A) JP-A-7-188540 (JP, A) JP-A-7-232412 (JP, A) JP 51-21587 (JP, A) JP 55-20786 (JP, A) JP 55-59929 (JP, A) JP 56-115261 (JP, A) Kai 59-101360 (JP, A) JP 60-124247 (JP, A) JP 63-10653 (JP, A) JP 63-264688 ( P, A) Tokuoyake Akira 47-19119 (JP, B1) US Patent 4264680 (US, A) (58 ) investigated the field (Int.Cl. ^7, DB name) B32B 1/00 - 35/00 B29C 47 / 00-47/96 C08K 3/00-13/08 C08L 1/00-101/16

Claims (4)

(57) [Claims] 1. A phosphorus compound represented by the following general formula (1): 0.01 to 0.5% by weight;
0.01 to 0.5% by weight of a phosphorus-based compound represented by the following general formula (1) and a phenol-based compound using the polycarbonate resin composition (A) containing 005 to 0.1% by weight as a base material 0.005-0.1 wt% and molecular weight 3
80 or more benzotriazole-based UV absorber 1.0 to
A polycarbonate coextrusion product comprising a polycarbonate resin composition (B) containing 15% by weight as a surface layer. [Formula 1] General formula (1) [One of R ₁ and R ₂ is an alkyl group having 1 to 4 carbon atoms and the other is hydrogen, or both are alkyl groups having 1 to 4 carbon atoms] 2. The polycarbonate coextrusion product according to claim 1, wherein the phenolic compound is a compound represented by the following general formula (2) or (3). Embedded image General formula (2) [R _{1 to} R ₄ are alkyl groups having 1 to 4 carbon atoms, n is 1
~ 3] ## STR00003 ## General formula (3) [R ₁ and R ₂ are an alkyl group having 1 to 4 carbon atoms, R ₃
Is an alkyl group having 1 to 30 carbon atoms, and n is 1 to 10] 3. A benzotriazole-based UV absorber having a molecular weight of 388, 2- [2-hydroxy-3 ′-(3 ′,
The polycarbonate coextrusion product of claim 1, which is 4 ', 5', 6'-tetra-hydrophthalimido-methyl) -5'-methylphenyl] benzotriazole. 4. A phosphorus compound represented by the above general formula (1) in an amount of 0.01 to 0.5% by weight and a phenol compound of 0.1.
A polycarbonate resin composition (A) containing 005 to 0.1 wt%, 0.01 to 0.5 wt% of a phosphorus compound represented by the following general formula (1), and 0.005 to a phenol compound. A polycarbonate resin composition (B) containing 0.1% by weight and 1.0 to 15% by weight of a benzotriazole-based ultraviolet absorber having a molecular weight of 380 or more is coextruded, and the polycarbonate resin composition (B) becomes a surface layer. A co-extrusion method of polycarbonate, characterized in that it is co-extruded.