JPH0920849A - Styrene-based resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject molding comprising a domain having a specific ratio of a major axis length/a minor axis length, excellent in direct cutting properties, useful as a packing sheet, etc. SOLUTION: In this molding comprising a continuous phase and a domain, the continuous phase is composed of a styrenic polymer having a syndiotactic configuration and the domain is constituted of another thermoplastic resin and/or a thermoplastic elastomer having >=2.1 ratio of a major axis length/a minor axis length. Preferably the minor axis length of the domain is <=10μm and a straight line cutting property index (d) shown by d=10/A is preferably >=0.996 when a cut in the vertical direction is made at an arbitrary end of the objective molding, one side formed by the cutting is fixed, the other is held by applying force in the direction of the end face, the torn tip reaches 10cm in the vertical direction to the end face and the actually torn length of the molding is Acm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a styrenic resin molded article, and more specifically, a styrenic polymer having a syndiotactic structure which is excellent in linear cutting property and is suitable as a film, sheet, yarn or the like as a matrix. The present invention relates to a styrene resin molded product.

[0002]

2. Description of the Related Art
The styrene-based polymer having a syndiotactic structure is
It is known to have excellent properties such as excellent heat resistance, solvent resistance, electrical properties, and low specific gravity, and various applications utilizing such properties are expected. In particular, in the use of films and sheets, various molding methods have been proposed in order to utilize the above excellent properties. For example, regarding a stretched film using a styrene-based polymer having a syndiotactic structure, JP-A-1-182348, JP-A-1-182346, JP-A-2-67328, and JP-A-2-1438.
51, JP-A-3-74437, JP-A-3-
86707, JP-A-3-124750, JP-A-3-131843, and JP-A-4-261485.
JP-A-5-200858, JP-A-6-5
7013, JP-A-6-57014, JP-A-6-57015, JP-A-6-57016,
JP-A-6-57017, JP-A-6-64036, JP-A-6-64037, and JP-A-6-653.
99, JP-A-6-65400, JP-A-6-
65401, JP-A-6-65402, JP-A-6-80793, JP-A-6-91748, JP-A-6-91749, and JP-A-6-9175.
No. 0, JP-A-6-99485, JP-A 6-1
No. 0071, No. 6-106616, No. 6-1078812, No. 6-107813, No. 6-114924, No. 6-11.
It is disclosed in Japanese Patent No. 4925.

However, a stretched film using such a conventional styrene-based polymer having a syndiotactic structure has good hand-tearability, but has a property of tearing only in a predetermined direction, that is, linear cuttability is insufficient. That is, it was inevitable that its use was limited.

Under these circumstances, the present invention provides a styrene-based resin molded product using a styrene-based polymer having a syndiotactic structure, which is excellent in linear cutting property and is particularly suitable as a film or sheet. That is the purpose. As a result of repeated studies to develop a styrene-based resin molded article using the styrene-based polymer having a syndiotactic structure having excellent linear cuttability, the present inventors
A styrene-based polymer having a syndiotactic structure is used as a continuous phase, and another thermoplastic resin and / or a thermoplastic elastomer is used as a domain, and the major axis length / minor axis length ratio of the domain is within a specific range. It has been found that the moldings according to can meet the purpose. The present invention has been completed based on such findings.

[0005]

Means for Solving the Problems That is, according to the present invention, in a molded article comprising a continuous phase and a domain, the continuous phase is made of a styrene polymer having a syndiotactic structure, and the domain has a major axis length / short axis A styrene-based resin molded article characterized by comprising another thermoplastic resin and / or thermoplastic elastomer having an axial length ratio of 2.1 or more, and the styrene-based resin molded article which is a sheet or a film. is there. Further, in the present invention, it is preferable that the minor axis length of the domain of the styrene resin molded body is 10 μm or less. Then, the present invention, in any one end of the styrene-based resin molded body, a cut is made in the vertical direction, one of which is caused by the cut is fixed, and in the case of pulling by applying a force in the end face direction while holding the other, When the actual torn length when the tip of the tear reaches 10 cm in the direction perpendicular to the end face is Acm, the linear cutability index (d) represented by the formula d = 10 / A is 0.996 or more. Is preferred. Hereinafter, the present invention will be described in more detail.

The styrenic resin molding of the present invention has a structure in which domains are uniformly dispersed in a continuous phase, and the styrene polymer having a syndiotactic structure is used for the continuous phase (matrix). To be Here, the syndiotactic structure in the styrene polymer is a syndiotactic structure having a high stereochemical structure, that is, a phenyl group or a substituted phenyl group which is a side chain with respect to the main chain formed from carbon-carbon bonds. Have a steric structure alternately located in the opposite direction, and their tacticity is quantified by a nuclear magnetic resonance method ( ¹³ C-NMR method) using isotope carbon. ^The tacticity measured by the ¹³ C-NMR method can be indicated by the abundance ratio of a plurality of continuous structural units, for example, diad in the case of 2, triad in the case of 3 and pentad in the case of 5. . The "styrene-based polymer having a syndiotactic structure" referred to in the present invention is usually a racemic dyad.
Polystyrene, poly (alkylstyrene), poly (halogenated styrene), poly (halogenated) having a syndiotacticity of 5% or more, preferably 85% or more, or 30% or more, preferably 50% or more in racemic pentad. Alkyl styrene), poly (alkoxy styrene), poly (vinyl benzoate), hydrogenated polymers thereof and mixtures thereof, or copolymers containing these as the main components. Here, poly (alkylstyrene) includes poly (methylstyrene), poly (ethylstyrene), poly (isopropylstyrene),
There are poly (tertiary butyl styrene), poly (phenyl styrene), poly (vinyl styrene), poly (vinyl naphthalene), etc., and as poly (halogenated styrene), poly (chloro styrene), poly (bromo styrene), Examples include poly (fluorostyrene). The poly (halogenated alkylstyrene) includes poly (chloromethylstyrene), and the poly (alkoxystyrene) includes poly (methoxystyrene) and poly (ethoxystyrene). Of these, particularly preferable styrene polymers include polystyrene, poly (p-methylstyrene), poly (m-methylstyrene), poly (p-tertiarybutylstyrene), poly (p-chlorostyrene), poly ( m-chlorostyrene), poly (p-fluorostyrene), hydrogenated polystyrene and copolymers containing these structural units such as copolymers of styrene and p-methylstyrene.

The styrene polymer having a syndiotactic structure is not particularly limited in its molecular weight, but generally has a weight average molecular weight of 10,000 or more, preferably
It is more than 50,000. Further, the molecular weight distribution is not limited to a wide range, and various kinds can be applied.
Here, if the weight average molecular weight is less than 10,000, the thermal properties and mechanical properties of the obtained molded article are deteriorated, which is not preferable. The styrene-based polymer having such a syndiotactic structure can be produced, for example, with reference to the technique disclosed in JP-A-62-187708. That is, a styrene-based monomer (a monomer corresponding to the styrene-based polymer) using a titanium compound and a condensation product of water and a trialkylaluminum as a catalyst in an inert hydrocarbon solvent or in the absence of a solvent. Can be produced by polymerizing. Regarding poly (halogenated alkyl styrene), JP-A-1-46912.
And on these hydrogenated polymers,
It can be produced by the methods described in JP-A-1-178505.

The styrene polymer having a syndiotactic structure used in this continuous phase may be used alone,
Two or more kinds may be used in combination. On the other hand, a thermoplastic resin and / or a thermoplastic elastomer other than the styrene polymer is used for the domain in the styrene resin molded product of the present invention. The type of the thermoplastic resin is not particularly limited, and examples thereof include polyphenylene ether; polyolefins such as polyethylene, polypropylene, polybutene and polypentene; polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyamides; polyphenylene sulfide and the like. Polythiolate; Polycarbonate; Polysulfone; Polyetheretherketone; Polyethersulfone; Polyimide;
Polymethylmethacrylate; ethylene-acrylic acid copolymer; acrylonitrile-styrene copolymer; acrylonitrile-chlorinated polyethylene-styrene copolymer; ethylene-vinyl acetate copolymer; ethylene-vinyl alcohol copolymer; vinyl chloride resin Chlorinated polyethylene; fluorinated polyethylene; polyacetal; thermoplastic polyurethane elastomer; 1,2-polybutadiene; styrene-maleic anhydride copolymer and the like, or modified ones thereof. Among these, especially polyolefins, olefin-polar vinyl monomer copolymers, polyamides, polycarbonates, polyarylates,
Polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide and the like are suitable.

The kind of the thermoplastic elastomer (including the rubber-like elastic body) is not particularly limited, but for example, styrene-butadiene block copolymer rubber (SB
R), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene block copolymer (SIR), styrene-isoprene-styrene block copolymer Copolymer (SIS), hydrogenated styrene-isoprene-styrene block copolymer (SEP)
S), ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), ethylene butylene rubber (EBM), or rubber modified with these. Among these, particularly preferable are SEBS, SBR, SB
S, SIS, SIR and SEPS.

In addition to the above, natural rubber, polybutadiene, polyisoprene, polyisobutylene, neoprene,
Polysulfide rubber, Thiokol rubber, Acrylic rubber,
Urethane rubber, silicone rubber, epichlorohydrin rubber, or rubbers obtained by modifying these may also be used.

In the present invention, these thermoplastic resins and thermoplastic elastomers may be used alone or in combination of two or more. Regarding the blending ratio of the styrene-based polymer having the syndiotactic structure and the other thermoplastic resin and / or the thermoplastic elastomer,
There is no particular limitation as long as the styrene-based polymer can form a continuous phase. For example, the weight average molecular weight is about 3
When syndiotactic polystyrene having a weight average molecular weight of about 20,000 is used and syndiotactic polystyrene having a weight average molecular weight of about 20,000 is used, the syndiotactic polystyrene becomes a continuous phase when blended at a weight ratio of 70:30.

Further, in order to obtain the styrene resin molded product of the present invention, its morphology control is extremely important. Therefore, when the melt index of a styrene-based polymer having a syndiotactic structure is MI _SPS and the melt index of another thermoplastic resin and / or a thermoplastic elastomer is MI _TER , MI _TER / MI _SPS
It is desirable that the ratio is 20 or less, preferably 15 or less. If this MI _TER / MI _{SP S} ratio exceeds 20, poor dispersion of other thermoplastic resins and / or thermoplastic elastomers is likely to occur, and it tends to be difficult to produce a molded product. The melt index is JIS K-72.
10 is a value measured under the conditions of a temperature of 300 ° C., a load of 2.16 kg, and 10 minutes. In the styrene-based resin molded product of the present invention, when the major axis length of the domain made of another thermoplastic resin and / or the thermoplastic elastomer is L ¹ and the minor axis length is L ² , the L ¹ / L ² ratio is It must be 2.1 or higher. If this L ¹ / L ² ratio is less than 2.1, the linear cut property is poor and the object of the present invention cannot be achieved. In order to obtain excellent linear cuttability, it is particularly preferable that the L ¹ / L ² ratio is 3.0 or more. Also, the minor axis length of the domain (L ² )
Is 10 μm or less, preferably 8 μm or less. When this uniaxial length exceeds 10 μm, poor dispersion of other thermoplastic resin and / or thermoplastic elastomer is likely to occur,
In addition to making it difficult to manufacture a molded product, the linear cut property is reduced,
Not preferred. The uniaxial length and the major axis length / minor axis length ratio of the domain are values obtained by a scanning electron microscope.

The styrene resin molded product of the present invention having such properties is particularly preferably in the form of a sheet or film. In addition, the manufacturing method is not particularly limited, and various methods can be used.

The above-mentioned styrene-based resin composition can be prepared in a desired amount within a range in which the styrene-based polymer having a syndiotactic structure, another thermoplastic resin and / or a thermoplastic elastomer are not impaired. Various additives used depending on the type, such as compatibilizers, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, inorganic fillers, antistatic agents, plasticizers, colorants, nucleating agents, etc. , Each of them is mixed in a predetermined ratio, and a commonly used method, for example, a single-screw extruder, a twin-screw extruder, a co-kneader,
It is carried out by melt-kneading using a multi-screw extruder or the like. Next, the styrene-based resin composition thus obtained is molded at a temperature not lower than the melting point and not higher than (decomposition point + 50 ° C.) to form a melt-molded body. The molding method is not particularly limited, and for example, a cast molding method or an inflation molding method can be used. Here, the decomposition point refers to a 1% weight loss temperature measured by thermogravimetry (TG). For example, in the case of syndiotactic polystyrene, the glass transition temperature is 90 to
100 ℃, melting point 260-270 ℃, decomposition point 320 ℃
And the melting temperature is preferably 270 to 350 ° C. Next, the melt-molded body is cooled to form a pre-molded body. At this time, the cooling method is not particularly limited, and for example, a method of contacting with a cooling drum can be preferably used. Here, the cooling temperature (refrigerant temperature) is usually 0 ° C.
Above, it is selected in the range of (glass transition point + 30 ° C) or less. 0 to 1 for syndiotactic polystyrene
30 degreeC is preferable and the range of 40-90 degreeC is especially suitable. The cooling rate is preferably in the range of 1 to 200 ° C / sec.

The preform thus obtained is preferably subjected to a stretching treatment in order to control the domains to a desired size. The stretching method is not particularly limited, and for example, chuck stretching or roll stretching is preferably used. In order to uniformly stretch and obtain a molded product having desired properties, the pre-molded product has a glass transition temperature or higher,
It is preferable to stretch the film at a temperature of (melting point -10 ° C) or lower about 1.1 to 10 times. The stretching speed is not particularly limited, but is preferably in the range of 1,000 to 50,000% / minute, and particularly preferably in the range of 3,000 to 20,000% / minute. The styrene resin molded product of the present invention thus obtained has a continuous phase composed of a styrene polymer having a syndiotactic structure, and a domain composed of another thermoplastic resin and / or thermoplastic elastomer. And the domain is controlled to a certain size,
Especially excellent in straight line cutting. This straight line cutting property is
When a cut is made in the vertical direction at any one end of the styrene resin molded product, one of the cuts is fixed, and the other is held and a force is applied in the end face direction to pull it, the tip of the tearing is 10 cm in the direction. When the actually torn length when reaching that point is Acm, the linear cutability index (d) represented by the formula d = 10 / A can be obtained and evaluated. The linear cuttability index (d) of the styrene-based resin molded product of the present invention is usually 0.996 or more.

[0016]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In addition, the measurement of each physical property was performed according to the method shown below. (1) Melt Index The melt index (MI _SPS ) of syndiotactic styrene polymer and the melt index (MI _TER ) of other thermoplastic resin or thermoplastic elastomer are JI.
According to SK-7210, MI measuring device TYPE C-5059D2S manufactured by Toyo Seiki Co., Ltd. was used, and the temperature was 300 ° C.
The measurement was performed under a load of 2.16 kg for 10 minutes. (2) Measurement of domain size of film Scanning electron microscope (JSM-61 manufactured by JEOL Datum)
00SCANNINGMICROSCOPE),
The uniaxial length (L ² ) and the major axis / minor axis length ratio (L ¹ / L ² ) of the domain of the film were determined. (3) Linear cutability index of film In a strip-shaped film having a width of 5 cm and a length of 15 cm,
2.5 cm in the width direction, length 3 in the direction perpendicular to the width direction
Make a cm cut. Next, when one of the resulting cuts is fixed and the other is held and a force is applied in the width direction to pull it, the tip of the slit is cut in the direction perpendicular to the width direction.
When the actual length torn when reaching 0 cm was Acm, the linear cutability index (d) was obtained from the equation d = 10 / A.

Reference Example 1 17 g of copper sulfate pentahydrate (Cu SO ₄ .5H ₂ O) was placed in a glass container having an inner volume of 500 ml replaced with argon.
(71 mmol), 200 ml of toluene and 24 ml (250 mmol) of trimethylaluminum were added, and the mixture was reacted at 40 ° C. for 8 hours. Then, the solid portion was removed to obtain 6.7 g of a contact product. Its molecular weight measured by freezing point depression method was 610. Production Example 1 Production of Styrenic Polymer Having Syndiotactic Structure In a reaction vessel having an internal volume of 2 liters, the contact product obtained in Reference Example 1 was used as an aluminum atom of 7.5 mmol and triisobutylaluminum was 7.5. Mmol, pentamethylcyclopentadienyl titanium trimethoxide 0.0
Take 38 liters and 1 liter of purified styrene,
A polymerization reaction was carried out at 5 ° C for 5 hours. After completion of the reaction, the catalyst component was decomposed with a methanol solution of sodium hydroxide, and the product was repeatedly washed with methanol and dried to obtain 466 g of a polymer. The weight average molecular weight of the obtained polymer was measured by gel permeation chromatography at 135 ° C. using 1,2,4-trichlorobenzene as a solvent.
And the weight average molecular weight / number average molecular weight is
It was 2.72. Further, the melting point and ¹³ C-NMR measurement confirmed that the obtained polymer was a polystyrene having a syndiotactic structure. The melt index (MI _SPS ) of this polystyrene was 8.1 g / 10 minutes.

Production Example 2 Production of Styrenic Polymer Having Syndiotactic Structure In Production Example 1, 0.96 liter of styrene and 0.04 liter of p-methylstyrene were used instead of 1 liter of styrene. Polymerization was performed in the same manner as in Production Example 1. The polymer obtained had a weight average molecular weight of 318,000.
And the weight average molecular weight / number average molecular weight was 2.51. The content of p-methylstyrene unit was 6 mol% as determined by ¹ H-NMR, and the melting point and ¹³ C-
From the NMR measurement, it was confirmed to be a styrene-p-methylstyrene copolymer having a syndiotactic structure. The melt index (M
I _SPS ) was 5.7 g / 10 minutes.

Example 1 90% by weight of syndiotactic polystyrene obtained as in Preparation Example 1 and 10% by weight of methylpentene polymer [TPX MX-002 manufactured by Mitsui Petrochemical Co., Ltd.] were used in a twin-screw extruder. The mixture was kneaded at 290 ° C and pelletized.
Then, the obtained resin composition is melt extruded at 300 ° C. by a single-screw 20 mm extruder equipped with a T die at the tip,
It was quickly brought into contact with a cooling roll whose temperature was adjusted to ℃ and then wound up to obtain a sheet-shaped original fabric. This raw fabric at 130 ℃ 4.
A stretched film was prepared by stretching the film twice. The domain size and linear cuttability index of this film are shown in Table 1.

Example 2 85% by weight of syndiotactic styrene-p-methylstyrene copolymer obtained as in Preparation Example 2 and hydrogenated styrene-isoprene-styrene block copolymer [Septone manufactured by Kuraray Co., Ltd. 1001] 15% by weight was used to prepare a stretched film in the same manner as in Example 1.
The domain size and linear cuttability index of this film are shown in Table 1.

Comparative Example 1 90% by weight of syndiotactic styrene-p-methylstyrene copolymer obtained as in Preparation Example 2 and hydrogenated styrene-butadiene-styrene block copolymer [Septone manufactured by Kuraray Co., Ltd.] A sheet was prepared using 10% by weight of KL8006]. The domain size and linear cuttability index of this sheet are shown in Table 1.

Example 3 The raw sheet obtained in Comparative Example 1 was stretched 3.8 times at 130 ° C. to prepare a stretched film. The domain size and linear cuttability index of this film are shown in Table 1.

[0023]

[Table 1]

[0024]

The styrenic resin molding of the present invention comprises a styrene polymer having a syndiotactic structure as a continuous phase and a thermoplastic resin and / or a thermoplastic elastomer as a domain. Is controlled to a specific size, and is particularly excellent in linear cutting property as compared with a molded product using a conventional styrene polymer having a syndiotactic structure. The styrene resin molded product of the present invention is preferably used as a film or sheet for packaging, packing, adhesive tape or the like, or as a fiber or nonwoven fabric useful for a filter or the like.

Claims (4)

[Claims] 1. A molded article comprising a continuous phase and a domain, wherein the continuous phase comprises a styrene polymer having a syndiotactic structure, and the domain has a major axis length / minor axis length ratio of 2.1 or more. A styrene-based resin molded article comprising the above thermoplastic resin and / or thermoplastic elastomer. 2. The styrene resin molding according to claim 1, wherein the minor axis length of the domain is 10 μm or less. 3. A styrene-based resin molded body according to claim 1, is provided with a notch in a vertical direction at one end thereof, one of the notches is fixed, and the other is held and pulled in a direction of an end face. In the case where the cutting tip has reached 10 cm in the direction perpendicular to the end face and the actual length of the tear is A cm, the linear cutability index (d) expressed by the equation d = 10 / A is The styrene-based resin molded product according to claim 1, which has a density of 0.996 or more. 4. The styrene resin molded product according to claim 1, which is a sheet, a film or a yarn.