JP6333045B2 - Vinyl chloride resin composition - Google Patents

Description

The present invention relates to a vinyl chloride resin composition. More specifically, vinyl chloride is excellent in moldability, particularly extruded tube moldability, sticking resistance and kink resistance when stored in a wound state of the molded tube, and can provide a tube suitable for medical use. The present invention relates to a resin composition.

Due to its excellent mechanical properties and economic efficiency, the vinyl chloride resin is a medical instrument such as a medical tube such as a catheter; a medical bag such as a blood bag, a drug solution bag and a drain bag; a joint member of a medical blood circuit And widely used as a material for medical containers and the like.

As a medical tube, for example, “a catheter composed of a soft vinyl chloride resin in which 20 to 100 parts by weight of a cyclohexane-1,2-dicarboxylic acid ester is blended with 100 parts by weight of a vinyl chloride resin. Patent Document 1) ”has been proposed. However, the extruded tube moldability, the sticking resistance and the kink resistance when stored in a wound state of the molded tube were not satisfactory.

JP 2005-40397 A

An object of the present invention is a vinyl chloride resin that is excellent in extrusion tube moldability, sticking resistance and kink resistance when stored in a wound state of the molded tube, and can obtain a tube suitable for medical use. It is to provide a composition.

As a result of intensive studies, the present inventor has found that the above-mentioned problems can be achieved by a resin composition of a vinyl chloride resin having a specific molecular weight and molecular weight distribution and a specific plasticizer.

That is, the present invention
(A) Vinyl chloride containing 100 parts by mass of a vinyl chloride resin satisfying the following characteristics (1) and (2); and (b) 15 to 150 parts by mass of diisononylcyclohexane-1,2-dicarboxylate plasticizer. System resin composition.
(1) The polystyrene-reduced mass average molecular weight of the differential molecular weight distribution curve measured by gel permeation chromatography is from 165,000 to 235,000.
(2) The molecular weight distribution Mw / Mn is 2.03 to 2.22. However, Mw is the polystyrene conversion mass average molecular weight of the differential molecular weight distribution curve measured by gel permeation chromatography, and Mn is the polystyrene conversion number average molecular weight.

According to a second invention, the component (b) is a mixture of cis isomer 80 to 100 mol% and trans isomer 20 to 0 mol%. It is a vinyl resin composition. However, the sum of the cis isomer and the trans isomer is 100 mol%.

A third invention is the vinyl chloride resin composition according to the first invention or the second invention, which is for extrusion molding.

A fourth invention is the vinyl chloride resin composition according to any one of the first to third inventions, which is for medical use.

A fifth invention is the vinyl chloride resin composition according to any one of the first to fourth inventions, which is for a tube.

The vinyl chloride resin composition of the present invention is excellent in moldability, particularly extrusion tube moldability. Further, the tube made of the vinyl chloride resin composition of the present invention is excellent in sticking resistance and kink resistance when stored in a wound state. Therefore, it can be suitably used as a medical tube.

The vinyl chloride resin composition of the present invention includes (a) a vinyl chloride resin that satisfies the following characteristics (1) and (2).
(1) The polystyrene-reduced mass average molecular weight of a differential molecular weight distribution curve (hereinafter sometimes abbreviated as GPC curve) measured by gel permeation chromatography (hereinafter sometimes abbreviated as GPC) is 165,000 to 235,000. It is.
(2) The molecular weight distribution Mw / Mn is 2.03 to 2.22. However, Mw is the polystyrene conversion mass average molecular weight of the differential molecular weight distribution curve measured by gel permeation chromatography, and Mn is the polystyrene conversion number average molecular weight.

The component (a) is a vinyl chloride resin and is not limited except that it satisfies the characteristics of the above (1) and (2), and any vinyl chloride resin can be used.

As the vinyl chloride resin, all polymers having a group represented by —CH ₂ —CHCl—, for example, vinyl chloride homopolymer; vinyl chloride / vinyl acetate copolymer, vinyl chloride / (meth) acrylic Acid copolymer, vinyl chloride / methyl (meth) acrylate copolymer, vinyl chloride / (meth) ethyl acrylate copolymer, vinyl chloride / maleic acid ester copolymer, vinyl chloride / ethylene copolymer, chloride Vinyl / propylene copolymer, vinyl chloride / styrene copolymer, vinyl chloride / isobutylene copolymer, vinyl chloride / vinylidene chloride copolymer, vinyl chloride / styrene / maleic anhydride terpolymer, vinyl chloride / styrene・ Acrylonitrile terpolymer, vinyl chloride / butadiene copolymer, vinyl chloride / isoprene copolymer, vinyl chloride / chlorinated polypropylene Other monomers copolymerizable with vinyl chloride and vinyl chloride, such as pyrene copolymers, vinyl chloride / vinylidene chloride / vinyl acetate terpolymers, vinyl chloride / acrylonitrile copolymers, vinyl chloride / vinyl ether copolymers Copolymers with vinyl chlorides; modified vinyl chloride homopolymers such as chlorinated vinyl copolymers and vinyl chloride copolymers; and chlorination similar in structure to vinyl chloride resins such as chlorinated polyethylene Examples thereof include polyolefins.

As said component (a), these 1 type, or 2 or more types of mixtures can be used. Among these, a vinyl chloride homopolymer is preferable from the viewpoints of moldability, sticking resistance, and kink resistance.

The component (a) has (1) a polystyrene-reduced mass average molecular weight of GPC curve measured by GPC of 165,000 to 235,000, preferably 165,000 to 205,000. When the polystyrene-reduced mass average molecular weight of the component (a) is in the above range, the moldability, sticking resistance, and kink resistance are surprisingly excellent.

The component (a) has (2) a molecular weight distribution Mw / Mn of 2.03 to 2.22, preferably 2.06 to 2.12. Here, Mw is the polystyrene equivalent weight average molecular weight of the GPC curve measured by GPC, and Mn is the polystyrene equivalent number average molecular weight of the GPC curve measured by GPC. When the molecular weight distribution Mw / Mn of the component (a) is in the above range, the moldability, sticking resistance, and kink resistance are surprisingly excellent.

The polystyrene-reduced molecular weight of the differential molecular weight distribution curve measured by gel permeation chromatography referred to in this specification is a measure that relatively indicates the molecular weight of the polyvinyl chloride resin in the molecular weight measurement by gel permeation chromatography. Polystyrene equivalent molecular weight is a calibration curve showing the relationship between retention capacity and polystyrene molecular weight obtained from monodisperse linear polystyrene of various molecular weights with known molecular weights measured using the same GPC measurement conditions as polyvinyl chloride resin. Is calculated by applying to the polyvinyl chloride resin. In other words, the molecular weight in terms of polystyrene is also equivalent to the molecular weight equivalent to polystyrene. The polyvinyl chloride resin and polystyrene (both have the same polystyrene equivalent molecular weight) eluted in the same holding capacity have the same radius of inertia. Therefore, the polystyrene-equivalent molecular weight of the polyvinyl chloride resin does not depend on the branched structure such that the resin is linear or has long chain branches, short chain branches, or both branches.

In this specification, GPC measurement can be typically performed as follows. High-performance liquid chromatography system “LC-2000Plus (trade name)” (Degasser, liquid pump “PU-2080 (trade name)”, autosampler “AS-2055 (trade name)”, column by JASCO Corporation A system including an oven and an RI (differential refractive index) detector.); As a column, two styrene divinylbenzene copolymer columns “GPC KF-806L (trade name)” of Showa Denko KK were connected and used. Using Wako Pure Chemical Industries, Ltd. special grade tetrahydrofuran (without stabilizer) as mobile phase; flow rate 1.0 ml / min, column temperature 40 ° C., sample concentration 1.5 mg / ml, sample injection volume 100 microliter Measure under conditions. Note that the amount of elution in each holding volume is determined from the amount detected by the RI detector, assuming that the refractive index of the polyvinyl chloride resin does not depend on the molecular weight.

A sample was prepared by adding 15 milligrams of the resin composition to 10 milliliters of tetrahydrofuran used in the above mobile phase and allowing it to stand at room temperature for dissolution. Then, the syringe filter “TITAN3-PTFE (trade name)” manufactured by TOMISIC Corporation. And filter with a pore size of 0.45 μm. The calibration curve from the retention capacity to the molecular weight in terms of polystyrene is the standard polystyrene “EasiCal PS-1 (trade name)” of Agilent Technology, Inc. (Plain A molecular weight 6870000, 841700, 152800, 28770, 2930; The molecular weight of Plain B is 2348000, 327300, 74800, 10110, 580). As an analysis program, “ChromNAV GPC (trade name)” of JASCO Corporation is used. As the column, in addition to using two “GPC KF-806L (product name)” in combination, one “GPC KF-802 (product name)” and “GPC KF-801 (product name)” 1 One book such as “GPC KF800D (trade name)” can be used in conjunction with two “GPC KF-806L (trade name)”.

For the theory of GPC and the actual measurement, refer to reference books such as "Size Exclusion Chromatography High-Performance Liquid Chromatography of Polymers, Author: Sadao Mori, First Edition, First Edition, December 10, 1991" can do.

The vinyl chloride resin composition of the present invention contains (b) diisononylcyclohexane-1,2-dicarboxylate plasticizer.

The component (b) is preferably a mixture of 80 to 100 mol% of cis isomer and 20 to 0 mol% of trans isomer. Here, the sum of the cis isomer and the trans isomer is 100 mol%. A resin composition having particularly excellent moldability, sticking resistance, and kink resistance can be obtained.

In addition, the ratio of the cis isomer and the trans isomer of the component (b) can be obtained from a nuclear magnetic resonance spectrum of protons (hereinafter sometimes abbreviated as ¹ H-NMR). The methine proton of dialkyl hexahydrophthalate shows a signal at 2.5-3.0 ppm, of which 2.7-3.0 ppm is in the cis isomer and 2.5-2.7 ppm is in the trans isomer. Be attributed. Thus, the cis isomer ratio is 2.7-3.0 ppm integrated area to 2.5-3.0 ppm integrated area, and the trans isomer ratio is 2.5-3.0 ppm integrated area 2. It can be determined as an integrated area of 5 to 2.7 ppm. The measurement of ¹ H-NMR can be performed with reference to, for example, JP-T-2005-504119. It can also be done by requesting measurements from Mitsui Chemical Analysis Center.

From the viewpoints of moldability, sticking resistance, and kink resistance, the blending ratio of the component (a) to the component (b) is from 15 to 150 components (b) with respect to 100 parts by mass of the component (a). Part by mass, preferably 20 to 120 parts by mass.

In the resin composition of the present invention, plasticizers other than the component (b), for example, phthalic acid ester, trimellitic acid ester, fatty acid dibasic ester, phosphoric acid ester, One or more epoxy plasticizers and polyester plasticizers may be included.

The resin composition of the present invention may further contain a vinyl chloride resin and a stabilizer usually used for the resin composition. Examples of the stabilizer include organotin compound-based, barium-zinc-based, calcium-zinc-based, and lead-based stabilizers. Among these, from the viewpoint of environmental problems, organotin compound-based, barium-zinc-based, and calcium-zinc-based stabilizers are preferable. As for the compounding quantity of a stabilizer, 0.1-10 mass parts is preferable with respect to 100 mass parts of said components (a).

The resin composition of the present invention may further contain various metal soaps, fatty acids, and lubricants such as polyethylene wax. The blending amount of the lubricant is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the component (a).

In the resin composition of the present invention, the vinyl chloride resin and various additives usually used in the resin composition (for example, heat stabilizer, filler, lubricant, Foaming agents, pigments, ultraviolet absorbers, etc.) and various fillers (for example, calcium carbonate, clay, talc, etc.) can be further included.

The resin composition of the present invention uses the above component (a), the above component (b), and optional components used as desired using a single screw extruder, a twin screw extruder, a roll, a mixer, various kneaders, or the like. And can be obtained by melt-kneading. Preferably, it can be obtained by melt kneading at a resin temperature of 150 to 180 ° C. using a pressure kneader.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

Raw materials used (a) Vinyl chloride resin:
(A-1) Vinyl chloride homopolymer having Mw = 170,000 and Mw / Mn = 2.04.
(A-2) Vinyl chloride homopolymer having Mw = 180,000 and Mw / Mn = 2.06.
(A-3) Vinyl chloride homopolymer having Mw = 200,000 and Mw / Mn = 2.12.
(A-4) Vinyl chloride homopolymer having Mw = 230,000 and Mw / Mn = 2.20.

(A ′) Comparative vinyl chloride resin:
(A′-1) Vinyl chloride homopolymer having Mw = 140,000 and Mw / Mn = 2.06.
(A′-2) Vinyl chloride homopolymer having Mw = 170,000 and Mw / Mn = 2.02.
(A′-3) Vinyl chloride homopolymer having Mw = 200,000 and Mw / Mn = 2.25.
(A′-4) Vinyl chloride homopolymer having Mw = 240,000 and Mw / Mn = 2.20.

(B) Diisononylcyclohexane-1,2-dicarboxylate plasticizer:
(B-1) A diisononylcyclohexane-1,2-dicarboxylate plasticizer having 80 mol% of cis isomer and 20 mol% of trans isomer.
(B-2) Diisononylcyclohexane-1,2-dicarboxylate plasticizer having 90 mol% of cis isomer and 10 mol% of trans isomer.
(B-3) Diisononylcyclohexane-1,2-dicarboxylate plasticizer having 100 mol% of cis isomer and 0 mol% of trans isomer.

(C) Optional component:
(C-1) Dioctyl tin mercapto stabilizer “ADEKA STAB 465 (trade name)” by ADEKA Corporation.
(C-2) Barium-zinc composite stability of ADEKA Corporation.
(C-3) Polyethylene wax lubricant “High Wax 4202E (trade name)” manufactured by Mitsui Chemicals, Inc.

Measuring method (1) Extruded tube formability:
Forming an extruded tube with an inner diameter of 2.1 mm and an outer diameter of 3.3 mm under the conditions of a resin temperature of 170 ° C. at the exit of the spiral die, a cooling water temperature of 15 ° C., a take-up speed of 10 m / min, and a vacuum degree of the vacuum water tank of −7.0 KPa. The drawdown property, the extruded tube surface appearance, and the extruded tube shape were visually observed and evaluated according to the following criteria.
A: The drawdown property, the extruded tube surface appearance, and the extruded tube shape are all good.
○: Although the surface of the extruded tube is somewhat rough, the drawdown property and the extruded tube shape are good.
Δ: The surface of the extruded tube is rough and the shape is disordered, but the drawdown property is good.
X: The surface of the extruded tube has significant skin roughness, and the shape is greatly disturbed. Also, the drawdown property is bad.

(2) Sticking resistance when the extruded tube is stored in a wound state:
A sample having a length of 5 meters was taken from the extruded tube obtained by the above-described evaluation of the extruded tube formability and wound into a donut shape (the size of the hole of the donut was 20 cm in diameter), and the temperature was 70 ° C. and the relative humidity was 60. The sample was allowed to stand in a constant temperature and humidity chamber of 1% for one week, adjusted for 24 hours in an environment of a temperature of 23 degrees and a relative humidity of 50%, and then evaluated according to the following criteria.
(Double-circle): The sticking between tubes did not arise at all, but was easily unwound.
○: Slight sticking between tubes.
(Triangle | delta): There exists sticking between tubes, and when a tube is touched by hand, there exists a feeling of stickiness a little.
X: There exists sticking between tubes, and a rough skin is visually observed on the surface of the tube.

(3) Kink resistance A sample having a length of 10 cm was taken from the extruded tube obtained by the above-described evaluation of the extruded tube formability, and after being conditioned for 24 hours in an environment of a temperature of 23 degrees and a relative humidity of 50%, Using a tensile / compression tester, compress the tube under the conditions of a compression speed of 120 mm / min and a distance between chucks of 50 mm, and determine the chuck travel distance (L) when kinks occur around the center of the sample in the longitudinal direction. And evaluated according to the following criteria. Here, “kink” refers to a state in which the tube is blocked by bending or the like and cannot function as a conducting tube.
○: L ≧ 40 mm
×: L <40 mm

Examples 1-11, Comparative Examples 1-4
The components (parts by mass) shown in any one of Tables 1 to 3 were melt-kneaded using a pressure kneader at a discharge resin temperature of 160 ° C. to obtain a vinyl chloride resin composition. The above evaluations (1) to (3) were performed. The results are shown in any one of Tables 1-3.

The vinyl chloride resin composition of the present invention is excellent in extrusion tube moldability. Moreover, the obtained tube is excellent in sticking resistance and kink resistance when stored in a wound state.

On the other hand, Comparative Example 1 in which Mw of component (a) is smaller than specified, Comparative Example 2 in which molecular weight distribution Mw / Mn of component (a) is smaller than specified, and Molecular weight distribution Mw / Mn of component (a) is smaller than specified. The comparative example 3 with a large comparative example 3 and the comparative example 4 with larger Mw of a component (a) are both inferior to extrusion tube moldability. Moreover, the obtained tube is inferior in both sticking resistance and kink resistance when stored in a wound state.

Claims (5)

(A) 100 parts by mass of a vinyl chloride resin satisfying the following characteristics (1) and (2); and (b) 15 to 150 parts by mass of a diisononylcyclohexane-1,2-dicarboxylate plasticizer , In the vinyl chloride resin composition, the component (b) is a mixture of 80 to 100 mol% of cis isomer and 20 to 0 mol% of trans isomer . However, the sum of the cis isomer and the trans isomer is 100 mol%.
(1) The polystyrene-reduced mass average molecular weight of the differential molecular weight distribution curve measured by gel permeation chromatography is from 165,000 to 235,000.
(2) The molecular weight distribution Mw / Mn is 2.03 to 2.22. However, Mw is the polystyrene conversion mass average molecular weight of the differential molecular weight distribution curve measured by gel permeation chromatography, and Mn is the polystyrene conversion number average molecular weight.
2. The vinyl chloride resin composition according to claim 1, which is used for extrusion molding.
The vinyl chloride resin composition according to claim 1 or 2, which is for medical use.
The vinyl chloride resin composition according to any one of claims 1 to 3 , wherein the vinyl chloride resin composition is used for a tube.
A medical tube comprising the vinyl chloride resin composition according to any one of claims 1 to 4.