JP2005105076A - Amorphous polyester-based resin composition and molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an amorphous polyester-based resin composition and molding that satisfy all of impact resistance, processability and weather resistance. <P>SOLUTION: The amorphous polyester-based resin composition comprises (A) 99-70 mass % of an amorphous polyester-based resin and (B) 1-30 mass % of a graft copolymer that is obtained by grafting 35-10 parts by mass of one or more kinds of vinyl-based monomer units onto 65-90 parts by mass an alkyl (meth)acrylate-based copolymer composed of 30-100 mass % of an alkyl (meth)acrylate monomer unit, 70-0 mass % of an aromatic vinyl monomer unit or an aromatic (meth)acrylate monomer unit, 10-0 mass % of a vinyl monomer unit copolymerizable with them and 5-0 mass % of a crosslinkable monomer unit. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an amorphous polyester resin composition and a molded body used for packaging materials and the like.

Amorphous polyester resins are widely used mainly for packaging materials such as bottles and sheets because they are excellent in transparency, mechanical properties, and gas barrier properties. In recent years, in packaging materials, containers have become larger in size and complicated in shape, so that higher impact resistance and workability are required.
Conventionally, as a means for improving the impact resistance of an amorphous polyester resin, a method of adding a rubbery polymer and a rubber-containing polymer to an amorphous polyester resin has been proposed. In particular, it is known that when a core-shell type graft polymer having a structure in which rubber-like polymer particles are surrounded by a glass-like polymer is added to an amorphous polyester-based resin, the impact resistance is improved ( For example, see Patent Document 1).
JP 2002-155914 A

Although the method of adding the rubbery polymer and the rubber-containing polymer as described above was effective in improving the impact resistance, the processability or weather resistance was impaired. Therefore, it has been difficult to satisfy all of the impact resistance, workability, and weather resistance of the finally obtained amorphous polyester resin composition.
This invention is made | formed in view of the said situation, and it aims at providing the amorphous polyester-type resin composition and molded object which satisfy all impact resistance, workability, and a weather resistance.

The amorphous polyester resin composition of the present invention comprises (A) 99 to 70% by mass of an amorphous polyester resin,
(B) Alkyl (meth) acrylate monomer unit 30 to 100% by mass, aromatic vinyl monomer unit or aromatic (meth) acrylate monomer unit 70 to 0% by mass, vinyl unit copolymerizable therewith One or two or more vinyl monomer units are added to 65 to 90 parts by mass of an alkyl (meth) acrylate copolymer comprising 10 to 0% by mass of a monomer unit and 5 to 0% by mass of a crosslinkable monomer unit. It contains 1 to 30% by mass of a graft copolymer having 35 to 10 parts by mass grafted thereon.
In the amorphous polyester resin composition of the present invention, one or two or more vinyl monomer units constituting the (B) graft copolymer are alkyl (meth) acrylate monomer units 70 to 100. It is preferable that the total amount is 100% by weight, 30% by weight of aromatic vinyl monomer units, and 0-20% by weight of vinyl monomer units copolymerizable therewith.
The molded article of the present invention is formed by molding the above-described amorphous polyester resin composition.

  The amorphous polyester resin composition and molded article of the present invention satisfy all of impact resistance, workability and weather resistance.

The amorphous polyester resin composition of the present invention contains (A) an amorphous polyester resin and (B) a graft copolymer.
(A) As an amorphous polyester-type resin, crystallinity is not substantially recognized or it is low, and transparency is favorable. As such an amorphous polyester resin, for example, a homopolymer obtained by condensation polymerization of a diol having 50% mol or more of ethylene glycol and a dicarboxylic acid having 50% mol or more of terephthalic acid or an alkyl ester thereof. Mention may be made of polymers, copolymers or mixtures thereof. Further, the copolymer may be, for example, a copolymer of another dicarboxylic acid such as isophthalic acid or halogenated terephthalic acid in a range of 50 mol% or less of the total carboxylic acids, or a range of 50 mol% or less of the total diol. And a copolymer of polyalkylene glycol (for example, diethylene glycol) or a copolymer of C _{3 to} C ₁₂ alkylene glycol (for example, 1,4-cyclohexanedimethanol).

  (A) Specific examples of the amorphous polyester resin include trade name “PETG 6763” (manufactured by Eastman Chemical Co., Ltd.) (dicarboxylic acid component comprising terephthalic acid, 30 mol% 1,4-cyclohexanedimethanol and 70 Copolyester copolymerized with a diol component consisting of mol% ethylene glycol), trade name “Provista” (dicarboxylic acid component consisting of terephthalic acid, 30 mol% 1,4-cyclohexanedimethanol and 70 mol% ethylene) A copolyester having a high melt viscosity obtained by copolymerizing a diol component composed of glycol and a very small amount of a third component is commercially available.

  (B) The graft copolymer always contains an alkyl (meth) acrylate monomer unit, and can optionally be copolymerized with an aromatic vinyl monomer unit or an aromatic (meth) acrylate monomer unit. One or two or more kinds of vinyl monomer units (hereinafter referred to as other vinyl monomer units), 65 to 90 parts by mass of an alkyl (meth) acrylate copolymer containing a crosslinkable monomer unit This is a graft of 35 to 10 parts by mass of vinyl monomer units.

(B) Although there is no restriction | limiting in particular as an alkyl (meth) acrylate monomer unit contained in the alkyl (meth) acrylate type copolymer which comprises a graft copolymer, The carbon number of an alkyl group is 1-18. An alkyl (meth) acrylate is mentioned.
Examples of the alkyl methacrylate having 1 to 18 carbon atoms in the alkyl group include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, methacrylic acid. Examples thereof include benzyl acid and phenyl methacrylate, and among them, methyl methacrylate and butyl methacrylate are preferable.
Examples of the alkyl acrylate having an alkyl group having 1 to 18 carbon atoms include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and acrylic acid Examples thereof include benzyl and phenyl acrylate. Among them, butyl acrylate, 2-ethylhexyl acrylate, and ethyl acrylate are preferable.

  The alkyl (meth) acrylate monomer unit content in the alkyl (meth) acrylate copolymer is 30 to 100% by mass. When the alkyl (meth) acrylate monomer unit content is within such a range, the impact resistance and weather resistance are excellent.

  The aromatic vinyl monomer unit used in the alkyl (meth) acrylate copolymer is a compound having one vinyl double bond and one or more benzene nuclei in the same molecule. Styrene, 4-methoxystyrene, 4-ethoxystyrene, 4-propoxystyrene, 4-butoxystyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-ethylstyrene, 2,5-dimethylstyrene 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 2,4-dichlorostyrene, 4-bromostyrene, 2,5-dichlorostyrene, α-methylstyrene, and the like. If these are used, the refractive index of the alkyl (meth) acrylate copolymer can be increased, and the refractive index of the amorphous polyester resin can be approached, so that the finally obtained amorphous polyester resin composition Can be made more transparent.

  The aromatic (meth) acrylate monomer unit is an ester of (meth) acrylic acid and an aromatic compound having an alcoholic hydroxyl group, and examples thereof include phenyl methacrylate.

  The content of the aromatic vinyl monomer unit or aromatic (meth) acrylate monomer unit in the alkyl (meth) acrylate copolymer is 70 to 0% by mass. When the content of the aromatic vinyl monomer unit or the aromatic (meth) acrylate monomer unit exceeds 70% by mass, the impact resistance tends to be lowered.

  Other vinyl monomer units include acrylonitrile, methacrylonitrile, vinylidene cyanate, vinyl cyanide compounds such as 1,2-dicyanoethylene, maleimide compounds, (meth) acrylic acid, hydroxyl groups or alkoxy groups. The (meth) acrylic acid ester contained is mentioned. Examples of (meth) acrylic acid ester containing hydroxyl group or alkoxy group include hydroxy acrylate such as hydroxyethyl acrylate and hydroxypropyl acrylate, hydroxy methacrylate such as hydroxyethyl methacrylate and hydroxypropyl methacrylate, methoxyethyl acrylate and ethoxyethyl Examples thereof include alkoxy acrylates such as acrylates, alkoxy methacrylates such as methoxyethyl methacrylate and ethoxyethyl methacrylate, and glycidyl methacrylate. However, it is not limited to these.

  The other vinyl monomer unit content in the alkyl (meth) acrylate copolymer is 10 to 0% by mass. When the content of other vinyl monomer units exceeds 10% by mass, impact resistance tends to be lowered.

Examples of the crosslinkable monomer unit include divinylbenzene, allyl methacrylate, divinylbenzene monoethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and the like. Among these, the combined use of divinylbenzene and allyl methacrylate is preferable.
The crosslinkable unit content in the alkyl (meth) acrylate copolymer is 5 to 0% by mass, preferably less than 1% by mass. When the crosslinkable monomer unit content exceeds 5% by mass, the impact resistance tends to be low.

The one or more vinyl monomer units grafted to the alkyl (meth) acrylate copolymer are not particularly limited, but are alkyl (meth) acrylate monomer units and aromatic vinyl monomer units. , Aromatic (meth) acrylate monomer units, other copolymerizable monomer units, and the like.
The alkyl (meth) acrylate monomer is an ester compound of acrylic acid or methacrylic acid, and is the same as the alkyl (meth) acrylate used for the alkyl (meth) acrylate copolymer. The aromatic vinyl monomer and other copolymerizable monomers are also the same as those used for the alkyl (meth) acrylate copolymer.

  (B) In the graft copolymer (B), when 100% by mass of all vinyl monomer units grafted to the alkyl (meth) acrylate copolymer, the grafted alkyl (meth) acrylate monomer The unit content is preferably 70 to 100% by mass, and more preferably 90 to 100% by mass. When the content of the alkyl (meth) acrylate monomer unit is less than 70% by weight, the compatibility with the amorphous polyester is lowered, and the impact resistance may be lowered.

  In (B) graft copolymer (B), 35 to 10 parts by mass of vinyl monomer units are grafted to 65 to 90 parts by mass of alkyl (meth) acrylate copolymer. By being such a ratio, it is excellent in impact resistance and workability.

  (B) Although there is no restriction | limiting in particular as the particle diameter of a graft copolymer, It is preferable that a mass mean molecular weight is 0.05-2 micrometers, It is more preferable that it is 0.08-0.8 micrometers, 0.09 It is especially preferable that it is -0.2 micrometer. When the mass average particle diameter is less than 0.05 μm, the impact resistance and dispersibility may be lowered, and when the mass average particle diameter is larger than 2 μm, the impact resistance may be lowered.

  (B) The graft copolymer can be obtained by emulsion polymerization, suspension polymerization, solution polymerization or the like, and emulsion polymerization is particularly preferable. For emulsion polymerization, known emulsification methods and polymerization sequences can be employed. Moreover, there is no restriction | limiting in particular in the preparation method of the monomer mixture in the case of superposition | polymerization, and methods, such as continuous 1 step addition and 2 steps addition, are employable.

  In this amorphous polyester-type resin composition, (A) 99-70 mass% of amorphous polyester-type resins and (B) 1-30 mass% of graft copolymers are included. By including the component (A) and the component (B) at such a ratio, the impact resistance, workability, and weather resistance are all satisfied.

  In the amorphous polyester resin composition, an acrylic polymer lubricant (C) can be added as a third component, particularly for the purpose of improving processability. (C) The acrylic polymer lubricant has a reduced viscosity of 1 L / g or less (measured at 25 ° C. by dissolving 0.1 g of the acrylic polymer lubricant (C) in 100 mL of chloroform), and has an alkyl group Alkyl group having 1 to 18 carbon atoms, alkyl acrylate having an alkyl group having 1 to 18 carbon atoms, and a vinyl-based monomer copolymerizable with at least one of these alkyl (meth) acrylates What is obtained by carrying out emulsion polymerization of the monomer mixture containing a body is preferable.

  The amount of the (C) acrylic polymer lubricant added to the (A) amorphous polyester resin is not particularly limited, but (A) 100 parts by mass of the amorphous polyester resin is preferably (C) acrylic. The system polymer lubricant is 0 to 10 parts by mass, more preferably 0 to 1 part by mass. If it exceeds 10 parts by mass, the inherent properties of the amorphous polyester resin may be lost.

  Also, for amorphous polyester resin compositions, antioxidants, heat stabilizers, light resistance improvers, ultraviolet absorbers, lubricants, plasticizers, mold release agents, antistatic agents used as usual additives Further, a slidability improver, a colorant and the like may be added.

  As a method for producing an amorphous polyester-based resin composition, component (A) and component (B) and other optional components are usually produced after component (A) and component (B) are separately produced in advance. Using a Henschel mixer, tumbler, etc., which is a blending method, and then shaping using an apparatus such as a single screw extruder, twin screw extruder, Banbury mixer, etc. to form an amorphous polyester resin composition The method of obtaining is mentioned.

The molded product of the present invention is obtained by molding the above-described amorphous polyester resin composition. There is no restriction | limiting in particular as the molding method, For example, injection molding, extrusion molding, compression molding, blow molding, vacuum molding etc. are mentioned.
Such a molded body is excellent in impact resistance, workability, and weather resistance, and therefore can be particularly suitably used as a packaging material.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, these are all illustrations and do not limit the content of this invention. In Examples and Comparative Examples, “part” and “%” represent “part by mass” and “% by mass”, respectively, unless otherwise specified.

[Production Example 1: Production of graft copolymer (G-1)]
200 parts of pure water, 0.6 part of sodium lauryl sulfate, 0.002 part of ferrous sulfate, 0.005 part of ethylenediaminetetraacetic acid 2Na salt, 0.2 part of sodium formaldehyde sulfoxide, 95 parts of butyl acrylate Part, 5 parts of styrene, 0.2 part of divinylbenzene, 0.5 part of allyl methacrylate and 0.1 part of diisopropylbenzene hydroperoxide were charged into a polymerization vessel equipped with a stirrer and polymerized at 50 ° C. for 2 hours and averaged at a polymerization conversion rate of 99%. A rubber latex (a) having a particle size of 0.12 μm was obtained.

225 parts of the rubber latex (a) (solid part 75 parts), pure water 200 parts, ferrous sulfate 0.002 parts, ethylenediaminetetraacetic acid 2Na salt 0.004 parts, formaldehyde sulfoxylate 0 .1 part was mixed. Next, this mixture was heated to 70 ° C., and a mixed solution of 24 parts of methyl methacrylate, 1 part of butyl acrylate and 0.2 part of cumene hydroperoxide was continuously added to obtain a graft copolymer (G-1) latex. It was. The average particle diameter of the obtained graft copolymer (G-1) latex was 0.15 μm.
Then, this graft copolymer (G-1) latex was coagulated with calcium acetate, heat-treated, washed, dehydrated and dried to obtain a powdered graft copolymer (G-1).

(Average particle size, particle size distribution)
In addition, the mass average particle diameter of the rubber particles or the graft copolymer in the latex was measured as follows. The obtained latex was diluted with distilled water, 0.1 ml of diluted latex having a concentration of about 3% was used as a sample, a CHDF2000 type particle size distribution meter manufactured by MATEC, USA, a flow rate of 1.4 ml / min, and a pressure of about 2.76 MPa ( Measured under the condition of about 4000 psi) and a temperature of 35 ° C. In this measurement, a capillary cartridge for particle separation and a carrier liquid were used to make the liquidity almost neutral. Before the measurement, a standard curve was prepared by measuring a total of 12 particle diameters from 0.02 μm to 0.8 μm using monodispersed polystyrene with a known particle diameter manufactured by DUKE Co., USA as the standard particle size substance. .

[Production Example 2: Production of graft copolymer (G-2)]
In a pressure-resistant autoclave, 150 parts of deionized water, 85 parts of 1,3-butadiene, 15 parts of styrene, 1.8 parts of divinylbenzene, 0.5 part of t-dodecyl mercaptan, 0.4 part of diisopropylbenzene hydroperoxide, pyrophosphoric acid A butadiene rubber latex was prepared by adding 1.0 part of sodium, 0.02 part of ferrous sulfate, 1.0 part of dextrose, and 3.0 part of potassium oleate and reacting at 50 ° C. for 15 hours while stirring. (B) was produced.

75 parts (as solid content) of the butadiene rubber latex (b) were charged into a flask and purged with nitrogen. Next, 1.2 parts of sodium bicarbonate was added as a 10% aqueous solution, stirred for 30 minutes, and 1 part of potassium oleate was added as a 7% aqueous solution to stabilize the rubber latex. Thereafter, 0.6 parts of Rongalite was added, and while maintaining the liquid temperature at 70 ° C., a total of 25 parts of a mixture of 10 parts of methyl methacrylate and 15 parts of styrene was graft-polymerized onto the butadiene rubber latex (b) to graft. Polymer (G-2) latex was obtained. The average particle size of the graft copolymer (G-2) latex was 0.12 μm.
Then, this graft copolymer (G-2) latex was coagulated with calcium acetate, heat-treated, washed, dehydrated and dried to obtain a powdered graft copolymer (G-2).

[Examples 1 and 2, Comparative Examples 1 and 2]
An amorphous polyester resin composition was obtained by blending as shown in Table 1, and this was evaluated as follows. The evaluation results are shown in Table 1. The amorphous polyester resin is Easter 6763 manufactured by Eastman Kodak Company. G431L, which is a lubricant, is a montanic acid wax manufactured by Clariant Japan. Moreover, C-1 in a table | surface is an acryl-type polymer lubricant, and used Mitsubishi Rayon Co., Ltd. Metabrene L-1000.
(Impact resistance)
It mix | blended as Table 1 and it melt-kneaded with the 8 inch heating roll made from a Kansai roll, and obtained the sheet | seat of thickness 1.0mm. Three sheets of this sheet were stacked and press-molded to produce a sheet having a thickness of 3.0 mm, and the impact strength of the sheet at 23 ° C. and 0 ° C. was evaluated using an Izod impact tester.
(Weatherability)
About the test sample adjusted to 23 degreeC and humidity 10% for 30 days, the impact strength of the test piece was measured similarly to the above, and the weather resistance was evaluated.

(Processability)
As indexes of workability, roll releasability, bleed during processing, and bleed by accelerated tests were evaluated.
In the evaluation of releasability, the roll releasability at the time of roll processing was visually determined as follows.
◎: Very good ○: Good △: Slightly poor releasability ×: Very poor releasability (However, there is no △ and × in this evaluation)
The bleed property during processing was evaluated visually during roll processing. In addition, the bleed property evaluation by the acceleration test was performed in the state of the molded product after annealing the press molded product at 80 ° C. for 3 days. Judgment of bleeding property is as follows.
◎: Very good ○: A very small amount of bleed out is observed △: Slightly bleed out is observed ×: There are many bleed outs (However, there is no △ and × in this evaluation)

As shown in Table 1, since the amorphous polyester resin compositions of Examples 1 and 2 satisfied Claim 1 of the present application, all of impact resistance, weather resistance, and workability were excellent. It was a thing.
On the other hand, since the amorphous polyester resin composition of Comparative Example 1 did not contain the (B) graft copolymer, the impact resistance was low.
The amorphous polyester resin composition of Comparative Example 2 had low weather resistance because the rubber component of the graft copolymer was not an alkyl (meth) acrylate copolymer but a butadiene polymer.

  The amorphous polyester resin composition of the present invention is suitably used for packaging materials.

Claims (3)

(A) 99 to 70% by mass of an amorphous polyester resin,
(B) Alkyl (meth) acrylate monomer unit 30 to 100% by mass, aromatic vinyl monomer unit or aromatic (meth) acrylate monomer unit 70 to 0% by mass, vinyl unit copolymerizable therewith One or two or more vinyl monomer units are added to 65 to 90 parts by mass of an alkyl (meth) acrylate copolymer comprising 10 to 0% by mass of a monomer unit and 5 to 0% by mass of a crosslinkable monomer unit. An amorphous polyester-based resin composition comprising 1 to 30% by mass of a graft copolymer grafted by 35 to 10 parts by mass.   (B) One or two or more vinyl monomer units constituting the graft copolymer are alkyl (meth) acrylate monomer units of 70 to 100% by weight, aromatic vinyl monomer units of 30 to 0% by weight. 2. The amorphous polyester resin composition according to claim 1, wherein the total amount of vinyl monomer units 0 to 20 wt% copolymerizable therewith is 100 wt%.   A molded article obtained by molding the amorphous polyester resin composition according to claim 1.