JPH0920812A - Styrenic resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a styrenic resin molding, excellent in linear cutting properties and useful for a film such as a tacky tape, a sheet, a filter, etc., by using a styrenic polymer having a specific crystal orientation coefficient, a specified crystallinity and a syndiotatlc configuration. SOLUTION: This styrenic resin molding is obtained by using a styrenic polymer having >=0.75 crystal orientation coefficient fc , >=35% crystallinity Xc and a syndiotactic configuration and has >=0.996 linear cutting index (d) represented by the formula (d)=10/A when the actually torn length is Acm at the time for the cut and torn tip to reach 10cm in the direction perpendicular to the end face in forming a notch in the perpendicular direction at one end in the styrenic resin molding, fixing either thereof produced by the notch, applying a force in the direction of the end face by holding the other and stretching the molding.

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 resin using a styrenic polymer having a syndiotactic structure, which is excellent in linear cutting property and is particularly suitable as a film or sheet. The present invention relates to a 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. The present inventor has conducted extensive studies to develop a styrene-based resin molded product using the styrene-based polymer having a syndiotactic structure excellent in the above-mentioned linear cut property, and as a result, a styrene-based polymer having a syndiotactic structure has been obtained. It was found that a molded product having a crystal orientation coefficient of 1 or more and a crystallinity of 2 or more can meet the purpose. The present invention has been completed based on such findings.

[0005]

That is, the present invention provides a molded product obtained from a styrene-based polymer having a syndiotactic structure, in which a crystal orientation coefficient (f) in the styrene-based polymer having the syndiotactic structure is used. _c ) is
The present invention provides a styrene-based resin molded article characterized by having a crystallinity (Xc) of 35% or more and a styrene-based resin molded article which is a sheet or a film. 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.

In the styrene resin molded product of the present invention, a styrene polymer having a syndiotactic structure is used as the base resin. 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 is the proportion of a plurality of continuous constitutional units, for example, diad in the case of 2 and triad in the case of 3.
The case of 5 can be indicated by a pentad. The "styrene-based polymer having a syndiotactic structure" referred to in the present invention is usually 75% or more, preferably 85% or more in racemic dyad, or 30% or more, preferably 50% or more in racemic pentad. Polystyrene having syndiotacticity, poly (alkylstyrene), poly (halogenated styrene), poly (halogenated alkylstyrene), poly (alkoxystyrene),
It means poly (vinyl benzoate), hydrogenated polymers thereof and mixtures thereof, or copolymers containing these as the main components. Here, as poly (alkylstyrene), poly (methylstyrene), poly (ethylstyrene), poly (isopropylstyrene), poly (tertiarybutylstyrene), poly (phenylstyrene), poly (vinylstyrene), There are poly (vinylnaphthalene) and the like, and as poly (halogenated styrene), there are poly (chlorostyrene), poly (bromostyrene), poly (fluorostyrene) and the like. 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 different molded articles obtained are deteriorated, which is not preferable. A styrene-based polymer having such a syndiotactic structure is disclosed in, for example, JP-A-62-18770.
It can be manufactured with reference to the technology disclosed in Japanese Patent Publication No. 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. Further, regarding poly (halogenated alkylstyrene), JP-A-1-46
No. 912, and these hydrogenated polymers can be produced by the methods described in JP-A-1-178505.

The styrene polymer having the syndiotactic structure may be used alone or in combination of two or more. Further, other thermoplastic resins and / or thermoplastic elastomers may be blended with the styrene-based polymer, if desired, within a range not impairing the object of the present invention. Here, the kind of the other thermoplastic resin is not particularly limited, but for example, polyphenylene ether;
Polyolefins such as polyethylene, polypropylene, polybutene and polypentene; polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyamides; polythioethers such as polyphenylene sulfide; polycarbonates; polyarylates; polysulfones; polyether ether ketones; polyether sulfones; 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-
Examples thereof include maleic anhydride copolymers and the like, or those obtained by modifying these. Among these, particularly, polyolefin, olefin-polar vinyl monomer copolymer, polyamide, polycarbonate, polyarylate, polyethylene terephthalate, polybutylene terephthalate,
Modified polyphenylene sulfide and the like are preferable.

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,
The styrene-based polymer is a matrix (if the structure is sea / island, the styrene-based polymer is the sea, and if two or more types of matrix are present, one of them is the styrene-based polymer). There is no particular limitation as long as it is available.
For example, a syndiotactic polystyrene having a weight average molecular weight of about 300,000 and a weight average molecular weight of about 2,000,000.
When the above polyamide is used in a weight ratio of 70:30, syndiotactic polystyrene serves as a matrix. In the styrene-based resin molded article of the present invention, it is necessary that the crystal orientation coefficient in the styrenic polymer having a syndiotactic configuration (f _c) is 0.75 or more. If the crystal orientation coefficient is less than 0.75, the linear cut property is poor and the object of the present invention cannot be achieved. In order to obtain excellent linear cuttability, the crystal orientation coefficient is preferably 0.80 or more. Here, the crystal orientation coefficient is a coefficient indicating the degree of orientation of the crystal c-axis in the film plane. The method of calculating the crystal orientation coefficient will be described in detail later.

Further, in the styrene resin molded product of the present invention, the crystallinity must be 35% or more. If the crystallinity is less than 35%, the characteristics of the crystalline styrene polymer will not be sufficiently exhibited. The preferred crystallinity is 38% or more. Here, the crystallinity refers to a value obtained by obtaining the difference between the enthalpy of fusion and the enthalpy of crystallization using a differential scanning calorimeter and expressing it as a percentage with respect to the enthalpy of fusion when the crystallinity is 100%. The method of calculating the crystallinity will be described later in detail. The styrene resin molded product of the present invention having such properties is preferably a sheet, film or yarn. The manufacturing method is not particularly limited, and various methods can be used. For example, first, a molding material containing a styrene-based polymer having a syndiotactic structure, and another thermoplastic resin and / or a thermoplastic elastomer that is used as needed within a range not impairing the object of the present invention is prepared. After that, the styrene resin molded product of the present invention is obtained by heating and melting this to obtain a pre-molded product, subjecting it to crystallization treatment if necessary, heat-stretching and then heat-treating as desired.

The above-mentioned molding material is prepared by using a styrene-based polymer having a syndiotactic structure, other thermoplastic resins and thermoplastic elastomers optionally used, and various additives, as long as the object of the present invention is not impaired. Agents, such as compatibilizers, antioxidants, ultraviolet absorbers, light stabilizers, lubricants, inorganic fillers, antistatic agents, plasticizers, colorants, nucleating agents, etc., in prescribed proportions. Mixing and commonly used methods such as twin screw extruder,
It is carried out by melt-kneading using a single-screw extruder, a co-kneader, a multi-screw extruder or the like. Next, the molding material thus obtained is usually molded at a temperature of 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 is
Refers to the 1% weight loss temperature as measured by thermogravimetry (TG). For example, in the case of syndiotactic polystyrene, the glass transition temperature is 90 to 100 ° C. and the melting point is 260 to
270 ° C, decomposition point is 320 ° C, melting temperature is 270
The temperature is preferably 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. or higher, (glass transition point + 3
0 ° C.) or less. In the case of syndiotactic polystyrene, the temperature is preferably 0 to 130 ° C, particularly 40
The range of to 90 ° C is suitable. The cooling rate is 1 to
The range of 200 ° C./second is preferable.

Next, if necessary, this preform may be subjected to crystallization treatment, but the method of crystallization treatment is not particularly limited, and for example, a method of performing in a temperature-controlled oven may be used. Can be used. In addition, this crystallization treatment is usually performed at a temperature in the range of cold crystallization temperature to melting point, preferably cold crystallization temperature to (melting point −10 ° C.) for usually 5 to 300 seconds, preferably 10 to 250 seconds. desirable. By this crystallization treatment, the crystallinity (Xc) of the preform is usually adjusted to the range of 25 to 55%. In order to control the crystal orientation coefficient and crystallinity of the styrene-based polymer having a syndiotactic structure to a desired value, the preform thus crystallized may be stretched, if desired. Good. In this case, the crystallization treatment may or may not be performed in advance regardless of the crystallinity of the preform used. When the stretching treatment is performed, the stretching method is not particularly limited, and for example, a chuck stretching method or a roll stretching method is preferably used.
In order to uniformly stretch and obtain a molded product having a desired crystal orientation coefficient and crystallinity, the preformed product is stretched at a temperature of not less than the glass transition temperature and not more than (melting point −10 ° C.) by about 2 to 10 times. Is preferred. If the stretching temperature is lower than the glass transition temperature, stretching is difficult, and if it exceeds (melting point −10 ° C.), the crystal orientation coefficient becomes low. From the aspects of stretchability and crystal orientation coefficient, the preferred stretching temperature is in the range of (glass transition temperature + 5 ° C) or higher and (melting point -15 ° C) or lower. Further, if the draw ratio is less than 2 times, it is difficult to obtain a molded article having a sufficient crystal orientation coefficient and crystallinity, and if it exceeds 10 times, breakage frequently occurs, which is not suitable for molding. From the aspects of crystal orientation coefficient, crystallinity, stretch break prevention, etc., the preferred stretch ratio is
The range is 2.5 to 8 times.

Further, the stretching speed is not particularly limited, but for example, the range of 1,000 to 50,000% / min is preferable, and the range of 3,000 to 20,000% / min is particularly preferable. Even a preform having a low degree of crystallinity can be crystallized and highly oriented by stretching at a high speed and a high ratio. The thus stretched material may be subjected to a heat treatment, if desired, in order to reduce uneven orientation. In this heat treatment, the orientation may be relaxed at the same time and the orientation coefficient may be lowered. Therefore, the heat treatment is performed in a tension state or a restricted shrinkage state at a glass transition temperature to a melting point, preferably (melting point −100 ° C.) or more, (melting point). It is advantageous to carry out the treatment at a temperature in the range of -5 ° C) or lower for about 0.5 to 120 seconds. Further, this heat treatment may be performed in an inert gas atmosphere such as argon gas or nitrogen gas. The styrenic resin molded product of the present invention thus obtained has a crystal orientation coefficient of the styrenic polymer having a syndiotactic structure is sufficiently high, and also has a high degree of crystallinity, and particularly a linear cut It has excellent properties. This straight line cutting property, at one end of the styrene resin molded body,
When making a cut in the vertical direction and fixing one side generated by the cut, holding the other and applying a force in the direction of the end face and pulling, the tearing tip is 1 in the direction perpendicular to the end face.
When the actually torn length when reaching 0 cm 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. The physical properties of the film were determined according to the methods described below. (1) Crystallinity Using a differential scanning calorimeter (DSC7 manufactured by Perkin Elmer Co., Ltd.), the crystallization enthalpy and the melting enthalpy at the time of heating from 50 ° C. to 300 ° C. at 20 ° C./minute are measured, and calculated from the following equation. . Crystallinity (%) = [melting enthalpy (J / g) -crystallization enthalpy (J / g)] / melting enthalpy (J / g) when the crystallinity is 100% x 100 When the crystallinity is 100% Enthalpy of fusion of 53J
/ G was used. (2) Crystal Orientation Coefficient The crystal orientation coefficient is a coefficient indicating the orientation distribution of the crystal c-axis of polymer molecules in the film plane. For example, in the case of a uniaxially stretched film, a wide-angle X-ray [X-ray generator in the equatorial direction with respect to the stretching direction [X-ray generator, manufactured by Rigaku Denki Co., Ltd., Rotaflex RU-200, counter manufactured by SPC, PSPC-30C,
On = 1.54Å] Bragg angle (2θ) = 6 in scattered image
The height of the peak [(hk0) plane] observed at ~ 14 ° is measured. This operation is repeated from the equatorial direction to the meridian direction to obtain the orientation distribution function of the (hk0) plane. (Hk
When the angle between the normal direction of the (0) plane and the stretching direction is α and the angle between the crystal c-axis and the stretching direction is β, the average of the orientation distribution functions with respect to the stretching direction of the crystal c-axis <cos ² β> Is represented by the following formula (i), and using this value, the orientation coefficient (fc) with respect to the stretching direction of the crystal c-axis is represented by the formula (ii) from the Hermans formula. <Cos ² β> = 1-2 <cos ² α> (i) fc = (3 <cos ² β> -1) / 2 (ii) (3) Linear cutability index Width 5 cm, In a strip-shaped film with 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 Copper sulfate pentahydrate (Cu SO ₄ .5H ₂ O) 17.8 was placed in a glass container having an inner volume of 500 ml replaced with argon.
g (71 mmol), 200 ml of toluene and 24 ml (250 mmol) of trimethylaluminum were added and 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 in an amount of 5 mmol, triisobutylaluminum in an amount of 5 mmol, and pentamethyl. Cyclopentadienyl titanium trimethoxide (0.025 mmol) and purified styrene (1 liter) were added at 90 ° C for 5 hours.
The polymerization reaction was performed for an hour. 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 308 g of a polymer. When the weight average molecular weight of this polymer was measured by gel permeation chromatography at 135 ° C. using 1,2,4-trichlorobenzene as a solvent, it was 400,0.
And the weight average molecular weight (Mw) / number average molecular weight (Mn) was 2.5. And melting point and ¹³ C
-By NMR measurement, it was confirmed that this polymer was polystyrene having a syndiotactic structure (hereinafter abbreviated as SPS).

Manufacture Example 2 The SPS obtained in Manufacture Example 1 was made into a T-die (width 2
It was melted at 300 ° C. with a single-screw 20 mm extruder equipped with 0 cm and a lip distance of 2 mm), and was quickly brought into contact with a cooling roll whose temperature was adjusted to 80 ° C., to obtain a winding stock. The crystallinity of this raw fabric was 5%.

Production Example 3 The raw fabric prepared in Production Example 2 was placed in a blower oven (MO-931 manufactured by Toyama Sangyo Co., Ltd.) heated to 180 ° C. under tension for 3 minutes for crystallization treatment. . The crystallinity of this raw fabric was 45%.

Example 1 A preform obtained as in Production Example 3 was prepared at 150 ° C. for 4.
The film was stretched to 0 times (stretching speed: 10,000% / min). Table 1 shows the crystallinity, crystal orientation coefficient, and linear cutability index of the obtained stretched film.

Comparative Example 1 Table 1 shows the crystallinity, the crystal orientation coefficient and the linear cutability index of the preform obtained as in Production Example 3.

Example 2 A preform obtained as in Production Example 3 was prepared at 230 ° C. for 5.
The film was stretched to 0 times (stretching speed: 10,000% / min). Table 1 shows the crystallinity, crystal orientation coefficient, and linear cutability index of the obtained stretched film.

Comparative Example 2 The raw fabric obtained as in Production Example 2 was stretched 4.2 times at 265 ° C. (stretching rate 10,000% / min). Table 1 shows the crystallinity, crystal orientation coefficient, and linear cutability index of the obtained stretched film.

Comparative Example 3 Table 1 shows the crystallinity, the crystal orientation coefficient, and the linear cutability index of the raw material obtained as in Production Example 2.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

The styrene resin molding of the present invention is obtained from a styrene polymer having a syndiotactic structure and has a sufficiently high crystal orientation coefficient and crystallinity. Compared with a molded product using a styrene-based polymer having a tic structure, it is particularly excellent in linear cutting property. 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 (3)

[Claims] 1. A molded product obtained from a styrene polymer having a syndiotactic structure, wherein the styrene polymer having a syndiotactic structure has a crystal orientation coefficient (f _c ) of 0.75 or more, And crystallinity (X
c) is 35% or more, a styrene-based resin molding. 2. A styrene-based resin molded body according to claim 1, is provided with a vertical cut at one end thereof, one of the cuts is fixed, the other is held and a force is applied in the end face direction to pull. 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. 3. The styrenic resin molded product according to claim 1, which is a sheet, a film or a yarn.