JP2000327893A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition which is excellent in thermal moldability, impact resistance, and flame retardance and does not exhibit discoloration even after thermal molding by adding an alkyl acid phosphate compound to a resin mixture comprising a polycarbonate resin and a polyester resin prepared by the polycondensation of a dicarboxylic acid component and a glycol component. SOLUTION: A polyester resin prepared by the polycondensation of a dicarboxylic acid component comprising terephthalic acid or its derivative and a glycol component containing at least 40 mol% 1,4-cyclohexanedimethanol is mixed with a polycarbonate resin having a viscosity average mol.wt. of 20,000-30,000, in a wt. ratio of (90/10)-(10/90). The objective thermoplastic resin composition, suitable for a transparent face plate material for outdoor use, is prepared by adding 0.01-3 pts.wt. at least one alkyl acid phosphate compound represented by formula I (wherein R is 1-20C alkyl; and n is 1 or 2) to 100 pts.wt. above-prepared resin mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition which can effectively prevent deterioration in color tone due to heating during molding and the like, and is suitably used as a material for a transparent face plate or the like for outdoor use.

[0002]

2. Description of the Related Art Conventionally, a transparent face plate disposed on the front side of a display sample such as a can in a vending machine, or a transparent face plate for an outdoor signboard used as a large molded signboard used in a gas station or the like, has been known. It is required to be excellent in processability such as printing, perforation, thermoforming, etc., impact resistance, flame retardancy, heat resistance, and transparency. Conventionally, those made of impact-resistant acrylic resin have been used in many cases. However, there has been a problem that they are easily burned and are easily broken. Therefore, development of a material that can satisfy the above-mentioned requirements has been desired.

In order to satisfy such demands, the present applicant has previously disclosed in Japanese Patent Application No. 11-41413 a polycondensation component of a dicarboxylic acid-based polycondensation component and a glycol-based polycondensation component as constituent resins. It has been proposed to use a mixed resin of a polyester resin obtained by this and a polycarbonate resin.

[0004]

However, when a mixed resin of the above-mentioned specific polyester resin and polycarbonate resin is molded into a plate or the like, the molded body obtained by heating at the time of the molding is slightly yellow. There is a problem that color tone is deteriorated. That is, if such a slight coloring such as yellow occurs, for example, when used as a transparent face plate for outdoor signage, the printing color takes on a yellow tint,
There was a problem in that the quality and quality of the transparent face plate for outdoor signboards were deteriorated, such as the sharpness of the printed design was reduced. Incidentally, such a problem of coloring due to heating during molding is a problem that hardly occurred in the polyester resin alone or the polycarbonate resin alone, and was used as a mixed resin system of the specific polyester resin and the polycarbonate resin. This is a problem that occurs specifically in some cases.

[0005] In order to solve the problem of color tone deterioration caused by heating at the time of molding, it is considered to add a blue dye or the like to a resin to suppress yellow coloring. At present, the fundamental problem has not been solved because the transmittance is lowered, the color tone becomes blue, and the printed color is different from the desired color.

The present invention has been made in view of such a technical background, and is excellent in thermoformability, impact resistance, flame retardancy, heat resistance, and transparency, and can be heated even during molding processing. It is an object of the present invention to provide a thermoplastic resin composition that does not change its color tone.

[0007]

Means for Solving the Problems In order to achieve the above object, the present inventors have conducted intensive studies and found that a specific amount of a specific structure is added to a resin in which a polycarbonate resin and a specific polyester resin are mixed at a specific mixing ratio. By adopting a structure containing a phosphate compound, it has been found that coloring due to heating during molding can be prevented and the desired thermoplastic resin composition can be obtained, thereby completing the present invention.

That is, the thermoplastic resin composition of the present invention comprises:
100 parts by weight of a mixed resin composed of 10 to 90% by weight of a polyester resin obtained by polycondensation of a dicarboxylic acid-based polycondensation component and a glycol-based polycondensation component, and 90 to 10% by weight of a polycarbonate resin. In contrast, the following general formula (I);

Embedded image (Wherein, R represents an alkyl group having 1 to 20 carbon atoms,
n represents 1 or 2), and 0.01 to 3 parts by weight of at least one kind of the alkyl acid phosphate compound represented by the formula (1).

Since the mixing ratio of the polyester resin and the polycarbonate resin is specified in a specific range, it is possible to provide both excellent moldability and excellent heat resistance, as well as good impact resistance and transparency. In addition, since both resins are hardly flammable resins, sufficient flame retardancy can be provided. Further, since the alkyl acid phosphate compound is contained in a specific amount with respect to the mixed resin, it is possible to effectively prevent coloring due to heating at the time of molding without deteriorating the above-mentioned various properties.

[0010] The polyester resin comprises one or more terephthalic acid-based polycondensation components selected from the group consisting of terephthalic acid and terephthalic acid derivatives, and 1,4-
The following general formula (II) obtained by polycondensing a glycol-based polycondensation component containing cyclohexanedimethanol at least 40 mol%;

Embedded image The polyester resin having a repeating unit represented by the following formula in the structure is preferable.

Since 1,4-cyclohexanedimethanol is contained in an amount of 40 mol% or more as a glycol-based polycondensation component, the refractive index of the polyester resin is very close to that of the polycarbonate resin, and excellent transparency can be obtained. In addition, the compatibility between both resins is also very good, so that excellent impact resistance is also ensured. In addition, since a terephthalic acid-based component is used as the dicarboxylic acid-based polycondensation component, excellent mechanical strength and chemical resistance are imparted, and heat resistance is further improved.

The phosphate compound has the following general formula (III):
And (IV);

Embedded image

Embedded image (Wherein, n represents 1 or 2), and is preferably one or more selected from the group consisting of phosphate compounds represented by the following formula, whereby coloring by heating during molding is further improved. It can be effectively prevented.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic resin composition of the present invention is characterized in that a specific alkyl acid phosphate compound is added to a mixed resin comprising 10 to 90% by weight of a specific polyester resin and 90 to 10% by weight of a polycarbonate resin. It is a specific amount.

The specific polyester resin is a resin obtained by polycondensing a dicarboxylic acid-based polycondensation component and a glycol-based polycondensation component.

The dicarboxylic acid-based polycondensation component is not particularly limited, but it is preferable to use one or more terephthalic acid-based components selected from the group consisting of terephthalic acid and terephthalic acid derivatives as the main components.

Above all, it is preferable that the proportion of the terephthalic acid component in the whole dicarboxylic acid polycondensation component is 95 mol% or more. If it is less than 95 mol%, the mechanical strength, heat resistance, and chemical resistance are undesirably reduced. It is particularly preferred that the content of the terephthalic acid-based component be 97 mol% or more based on the whole dicarboxylic acid-based polycondensation component.

The terephthalic acid derivative includes, for example, dimethyl terephthalate, diethyl terephthalate and the like, among which dimethyl terephthalate is preferred.

On the other hand, glycol-based polycondensation components include:
Although not particularly limited, it is preferable to use 1,4-cyclohexanedimethanol at least 40 mol%. That is, the proportion of 1,4-cyclohexanedimethanol in the entire glycol-based polycondensation component is preferably set to 40 mol% or more. If the amount is less than 40 mol%, the transparency is lowered, and the compatibility with the polycarbonate resin is lowered, so that the mechanical strength such as impact strength is lowered. Among them, the proportion of 1,4-cyclohexanedimethanol in the entire glycol-based polycondensation component is preferably 50 mol% or more. In this case, the refractive index of the obtained polyester resin is extremely smaller than that of the polycarbonate resin. Excellent transparency can be obtained from the approximation,
Since the compatibility of both resins is also very good, excellent impact resistance can be secured. In addition, 1,4-
Cyclohexanedimethanol has two types of isomers, cis-type and trans-type, and any of them may be used.

The glycol-based polycondensation component used in combination with 1,4-cyclohexanedimethanol includes, for example, ethylene glycol, propylene glycol, etc., which have a good balance of physical properties, are widely industrially produced and are inexpensive. Ethylene glycol is particularly preferred. Of course, 1,4-glycol-based polycondensation component
It is good also as what uses 100% of cyclohexane dimethanol.

For the reasons described above, the polyester resin used in the present invention may be one or more terephthalic acid-based polycondensation components selected from the group consisting of terephthalic acid and terephthalic acid derivatives, and 1,4-cyclohexane The following general formula (II) obtained by polycondensing a glycol-based polycondensation component containing 40 mol% or more of dimethanol:

Embedded image It is particularly preferable to use a polyester resin having a repeating unit represented by in the structure.

On the other hand, as the polycarbonate resin, for example, a resin produced by a known method from a bisphenol compound can be used, and various types may be used in combination.
000 is preferred. If it exceeds 30,000, moldability deteriorates, and if it is less than 20,000, impact resistance decreases, which is not preferable. Particularly preferred are those having a viscosity average molecular weight of 25,000 to 27000.

In the present invention, the mixing weight ratio of the polyester resin / polycarbonate resin is from 10/90 to 90/90.
/ 10. When the mixing ratio of the polycarbonate resin is smaller than the above range, the heat resistance becomes insufficient. For example, it is difficult to prevent the deformation from occurring under the hot summer sun. On the other hand, if the mixing ratio of the polycarbonate resin is larger than the above range, a preliminary drying step is required to prevent foaming in thermoforming such as vacuum forming, which requires a large amount of time and reduces productivity.
In addition, the molding cycle becomes longer, and the moldability decreases. Among them, the mixing weight ratio of polyester resin / polycarbonate resin is preferably in the range of 20/80 to 80/20, and particularly preferably in the range of 30/70 to 70/30.

The thermoplastic resin composition of the present invention has the following general formula (I) based on 100 parts by weight of the mixed resin (specific polyester resin / polycarbonate resin) according to the above constitution.

Embedded image (Wherein, R represents an alkyl group having 1 to 20 carbon atoms,
n represents 1 or 2) and at least one of 0.01 to 3 parts by weight of an alkyl acid phosphate compound represented by the following formula:

When the alkyl acid phosphate compound having the specific structure is contained in a specific amount, the various properties (excellent moldability, heat resistance, flame retardancy, etc.) secured by the mixed resin are degraded at all. Without coloring, it is possible to effectively prevent coloring due to heating during molding. If the amount is less than 0.01 part by weight with respect to 100 parts by weight of the mixed resin, a sufficient coloring prevention effect cannot be obtained, while if it exceeds 3 parts by weight, a sufficient coloring prevention effect cannot be obtained similarly. Above all, the content of the phosphate compound is preferably more than 0.01 part by weight and not more than 2 parts by weight, more preferably more than 0.1 part by weight based on 100 parts by weight of the mixed resin according to the above constitution. The range is 1.5 parts by weight or less, most preferably more than 0.1 part by weight and 1 part by weight or less.

In the mixed resin system (specific polyester resin / polycarbonate resin system), coloring caused by heating at the time of molding is caused by the unreacted product (catalyst) of the catalyst used in the synthesis of the constituent resin in the resin composition. When the amount of (residue) is large, it becomes very noticeable and becomes a problem particularly. However, even in such a case, the coloring by heating at the time of molding processing can be sufficiently performed by using the resin composition of the present invention. Can be prevented. Even if additives such as 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite and a high molecular weight hindered phenol compound are contained in addition to the above-mentioned specific alkyl acid phosphate compound, catalyst In a system with a large amount of residue, it is difficult to prevent coloring due to heating during molding.

Examples of the alkyl acid phosphate compound include methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, 2-ethylhexyl acid phosphate, isodecyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, and stearyl acid. Phosphate,
Oleyl acid phosphate and the like may be mentioned, and the monoester of these compounds may be used alone, the diester may be used alone, or a mixture thereof. The alkyl acid phosphate compound may be used as it is, or may be used in the form of a salt such as an alkali metal salt or an amine salt.

Among them, as the alkyl acid phosphate compound, it is preferable to use butyl acid phosphate or stearyl acid phosphate.
That is, the following general formulas (III) and (IV);

Embedded image

Embedded image (However, in the formula, n represents 1 or 2) It is preferable to use one or more selected from the group consisting of the compounds represented by the following formulas, whereby coloring by heating at the time of molding processing is more effective. Can be prevented.

As a commercial product of the compound represented by the general formula (III), for example, JAMP-4 (manufactured by Johoku Chemical Co., Ltd.) can be exemplified. As a commercially available product of the compound represented by the general formula (IV), for example, JAMP-18 (manufactured by Johoku Chemical Co., Ltd.) can be exemplified.

The above resin composition contains a lubricant such as glycerin monostearate, an ultraviolet absorber such as benzotriazole and benzophenone, a light stabilizer such as hindered amine and a heat stabilizer such as phenol and phosphorus. Various additives such as an antistatic agent, an antioxidant, a colorant, and glass fiber can be appropriately compounded as long as the effects of the present invention are not impaired. Further, other synthetic resins and the like may be contained as long as the effects of the present invention are not impaired.

The thermoplastic resin composition of the present invention can be obtained by blending and kneading the above-mentioned constituent materials, for example. The kneading may be performed using a known blender such as a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single screw extruder, a twin screw extruder, or the like. The heating temperature at the time of kneading is usually in the range of 200 to 340 ° C., and is appropriately set according to the mixing ratio of the mixed resin.

When a transparent face plate for outdoor use such as a face plate for a vending machine, a face plate for an outdoor signboard, etc. is manufactured using the resin composition of the present invention, the resin composition is obtained by thermoforming. Can be. As the thermoforming method, for example, a thermoforming method known in the plastics processing technology, such as extrusion molding, calendering molding, and vacuum molding, can be used. In addition, excellent weather resistance can be imparted by a method such as forming the face plate into a laminated structure.

[0032]

Next, specific embodiments of the present invention will be described. It should be noted that the present invention is not particularly limited to the embodiments.

Example 1 "PCTG 5445" (manufactured by Eastman Chemical Co.) (a dicarboxylic acid-based polycondensation component having a terephthalic acid ratio of 99 mol% or more, and 1,4-
70 parts by weight of a polyester resin obtained by polycondensation of a glycol-based polycondensation component having a cyclohexanedimethanol ratio of 50 mol%) and "Iupilon E2000F" (manufactured by Mitsubishi Engineering-Plastics Corporation) having a viscosity average molecular weight of 27,000 30 parts by weight of a polycarbonate resin) and 0.02 parts by weight of "JAMP-18" (stearyl acid phosphate; a mixture of a monostearyl compound and a distearyl compound) manufactured by Johoku Chemical Co., Ltd. are mixed by a tumbler mixer, and the mixture is 40 mm in inner diameter. To form a transparent face plate for outdoor use having a thickness of 3.0 mm.

<Examples 2 to 10 and Comparative Examples 4 and 5> A resin having a thickness of 3.0 mm was prepared in the same manner as in Example 1 except that a resin composition in which the materials shown in the table were mixed at the ratios shown in the table was used. A face plate was manufactured.

<Comparative Examples 1 to 3> The procedure of Example 1 was repeated, except that the compounds shown in Table 3 were added and compounded in place of the stearyl acid phosphate compound.
A 0 mm face plate was manufactured. In the table, “HP-10”,
"2112" and "AO-60" are trade names of additives of Asahi Denka Kogyo Co., Ltd., and "HP-10" is 2,2-methylenebis (4,6-di-t-butylphenyl) octylphos. "2112" is a phosphite compound, and "AO-60" is a high molecular weight hindered phenol compound.

Comparative Example 6 A face plate having a thickness of 3.0 mm was prepared in the same manner as in Example 1, except that the resin composition was a polyester resin (PCTG 5445) alone and a system not containing a stearyl acid phosphate compound. Was made.

Comparative Example 7 A 3.0 mm-thick face plate was prepared in the same manner as in Example 1 except that the resin composition was a polycarbonate resin (Iupilone E2000F) alone and a system not containing a stearyl acid phosphate compound. Was made.

Comparative Example 8 A transparent plate made of impact-resistant acrylic resin ("SUMIPEX GT", manufactured by Sumitomo Chemical Co., Ltd., 3 mm in thickness).

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

Each face plate manufactured as described above was evaluated based on the following test method.

<Yellowness test method> The yellowness of each face plate was measured in accordance with JIS K7103.

<Printing Color Development Test Method> Screen printing was performed on one side of the face plate with white ink (product number STR, manufactured by Seiko Advance Co., Ltd.), and after sufficient drying, the color development of printing was visually observed from the non-printing side. Was evaluated. The printability of the impact-resistant acrylic plate of Comparative Example 8 was equivalent to “○” (passed), and those slightly yellowish compared to Comparative Example 8 were rated “△”. Those markedly remarkable in yellow coloration were evaluated as “x”.

<Impact resistance test method> A drop weight impact test (spherical weight 2 sphere (1k
g)). Those that did not crack in this falling weight impact test were evaluated as “○” (pass), and those that cracked were evaluated as “x” (fail).

<Heat Resistance Evaluation Method> The heat resistance was determined by the deflection temperature under load of the face plate (in accordance with HDT, JIS K7207,
18.5 MPa).

As is clear from the table, the transparent face plate for outdoor use manufactured using the thermoplastic resin composition of the present invention is:
The degree of yellowness after molding is small (there is almost no coloring due to heating during molding), yellowing is not conspicuous on the printing surface, a desired printing color can be obtained, and printing color development is excellent. In addition, it was confirmed that the material was excellent in impact resistance and heat resistance, and was suitable as a resin composition for a transparent face plate for outdoor use.

On the other hand, in Comparative Examples 1 to 3, which do not contain the alkyl acid phosphate compound, the yellowness is large, the printing color is different from the desired color tone, and the printing color developability is poor. Comparative Examples 4 and 5 in which the content of the alkyl acid phosphate compound is out of the specified range of the present invention.
In each case, the yellowness was large, and the effect of preventing coloring due to heating during molding was insufficient.

In Comparative Example 6 in which the polyester resin was used alone as the constituent resin, the printing color developability was good but the heat resistance was insufficient. Further, in Comparative Example 7 in which the polycarbonate resin was used alone as the constituent resin, although the print coloring property was good, the thermoforming temperature was too high, so that thermoforming was difficult.

[0050]

As described above, the thermoplastic resin composition of the present invention has both excellent moldability and excellent heat resistance because the mixing ratio of the polyester resin and the polycarbonate resin is specified in a specific range. be able to. In addition, since both resins are hardly flammable resins, they have sufficient flame-retardant performance and can also secure good impact resistance and transparency. Further, since the specific amount of the specific alkyl acid phosphate compound is contained, it is possible to effectively prevent the occurrence of coloring due to heating at the time of molding without deteriorating the above-mentioned various performances, and to reduce the yellow color on the printing surface. Coloring is not conspicuous and a desired printing color can be obtained, and the printing color developing property is excellent. In addition, coloring over time due to heat history and the like of the molded product can be effectively prevented. Therefore, it is particularly suitable as a resin composition for outdoor printing signboard face plates. In addition, since it is excellent in anti-coloring properties, it can be used as a resin composition for exteriors, visors, and lighting covers, for example, in addition to the signboard materials.

The polyester resin comprises one or more terephthalic acid-based polycondensation components selected from the group consisting of terephthalic acid and terephthalic acid derivatives, and a glycol-based resin containing 40 mol% or more of 1,4-cyclohexanedimethanol. In the case of a polyester resin having in its structure a repeating unit represented by the general formula (II) obtained by polycondensation with a polycondensation component, it contains 1,4-cyclohexanedimethanol in an amount of 40 mol% or more. Because of this, the refractive index of the polyester resin is very close to the refractive index of the polycarbonate resin, and excellent transparency is obtained. In addition, the compatibility of both resins is also very good, and the impact resistance is excellent. Nature can be secured. In addition, since a terephthalic acid-based component is used as the dicarboxylic acid-based polycondensation component, excellent mechanical strength and chemical resistance can be imparted, and heat resistance can be further improved.

When the specific alkyl acid phosphate compound is one or more selected from the group consisting of the compounds represented by the general formulas (III) and (IV), heating during molding Can be further prevented.

Claims (3)

[Claims] 1. A polyester resin obtained by polycondensing a dicarboxylic acid-based polycondensation component and a glycol-based polycondensation component in an amount of 10 to 90% by weight, and a polycarbonate resin of 90 to 1%.
0% by weight, and 100 parts by weight of the mixed resin, with respect to the following general formula (I): (Wherein, R represents an alkyl group having 1 to 20 carbon atoms,
wherein n represents 1 or 2) at least one kind of an alkyl acid phosphate compound represented by the formula (1): 0.01 to 3 parts by weight. 2. The polyester resin contains one or more terephthalic acid-based polycondensation components selected from the group consisting of terephthalic acid and terephthalic acid derivatives and 40 mol% or more of 1,4-cyclohexanedimethanol. The following general formula (II) obtained by polycondensing a glycol-based polycondensation component: The thermoplastic resin composition according to claim 1, which is a polyester resin having a repeating unit represented by the following formula in the structure. 3. The method of claim 1, wherein the alkyl acid phosphate compound is represented by the following general formulas (III) and (IV): Embedded image The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is at least one selected from the group consisting of phosphate compounds represented by the following formula (where n represents 1 or 2).