JPS5968362A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide a compsn. flexible in the absence of plasticizers, excellent in transparency, heat resistance, weatherability, and low-temp. flexibility, by incorporating ethylene/vinyl acetate copolymer and particular block copolymer with vinyl chloride resin. CONSTITUTION:A thermoplastic resin compsn. which contains, as components, vinyl chloride resin, ethylene/vinyl acetate copolymer, and block copolymer of formula A-B-A (wherein A is a styrene polymer; B is a diene polymer). Said compsn. is transparent and excellent in flexibility, and has remarkably good heat resistance, thus being capable of use in a variety of fields where conventional resins are hardly usable so far, such as medical equipment (blood bag, infusion bag, catheter, blood circuit, circuit for artificial heart, surgical glove, etc.). In addn., it can also be used in laser, film for table ware package, tape substrate, wire coating materials, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The thermoplastic resin composition of the present invention has excellent transparency, heat resistance, weather resistance, low-temperature flexibility, processing properties, sealing properties, and blocking resistance. Concerning thermoplastic materials.

Conventionally, compositions in which polyvinyl chloride II l1li yarn is blended with a large amount of flexible l5IJ such as dioquidyl phthalate and diocdyl adipate have been used in many fields because they have excellent strength properties while being flexible. It's here.

However, such silk nv. Because these products contain a large amount of plasticizer, they may deteriorate during long-term use or
During use, the plasticizer migrates and the soft layer 1 is lost, resulting in embrittlement. In addition, the plasticizers mentioned above are eluted into the blood and infusions in Wl and K used in blood bags, infusion bags, etc. in the medical field, and this poses a threat to the health of people receiving treatment using these materials. There were problems that threatened common sense.

In order to eliminate the above-mentioned drawbacks of conventional soft vinyl chloride resins, for example, compositions in which chlorinated polyethylene is mixed with vinyl chloride resin, resins in which vinyl chloride is graft copolymerized to ethylene/vinyl acetate copolymer, etc. have been adopted. It has been. However, in none of these properties such as transparency and heat resistance were sufficiently improved.

In order to solve the above problems, the present inventors have conducted various studies on threads made by blending ethylene/vinyl acetate copolymers with vinyl chloride resins and adding a specific Glock copolymer. It is flexible without adding any agent,
In addition, they discovered that a composition with excellent transparency, heat resistance, weather resistance, and low-temperature flexibility could be obtained, leading to the completion of the wood invention.

The gist of the present invention is as follows: (a) vinyl chloride resin, (b) ethylene/vinyl acetate copolymer, (/→formula A
A block copolymer represented by -B-A,
The fl styrene thread heavy thread combination is a diene thread polymer, and exists in a thermoplastic resin composition containing the above (a), (b), and (c) as components.

Next, the thermoplastic resin composition of the present invention will be explained in more detail.

The vinyl chloride resin used in the present invention,
These are vinyl chloride homopolymers and copolymers, and vinyl chloride-based copolymers include vinyl chloride-ethylene copolymers,
Vinyl chloride/propylene copolymer, vinyl chloride/vinyl acetate copolymer, vinyl chloride/ethyl acrylate copolymer, vinyl chloride/ethyl acrylate copolymer, vinyl chloride/2-ethylhexyl acrylate copolymer, vinyl chloride・Acryloni) IJ copolymer etc. are used. Furthermore, vinyl chloride-based graft copolymers obtained by graft copolymerizing polymerizable Q'-fa bodies such as pudyl acrylate, 2-ethylhexyl acrylate, butadiene, etc. to the above-mentioned vinyl chloride-based 4'# fats are also available. can be used.

The degree of polymerization of the vinyl chloride thread resin is 600 to 300.
0 is preferred.

Among the above-mentioned vinyl chloride-based resins, particularly preferred are copolymers of vinyl chloride and α-olefin, especially vinyl chloride/ethylene copolymers, and those having ethylene content K of 2 to 15 furrows. .

As the ethylene/vinyl acetate light polymer used in the present invention, ethylene/vinyl acetate copolymers and those containing ethylene/vinyl acetate/ash oxide in a range of % by weight are preferably used. Among the above-mentioned ethylene/vinyl acetate copolymers, particularly preferred are Mononoke ethylene/vinyl acetate.
It is a terpolymer with varying degrees of oxidation.

The ethylene/vinyl acetate/carbon oxide copolymer has an ethylene content of 40 to 85% by weight and a vinyl acetate content of 1% by weight.
5 to 50% by weight, - 5 to 20% by weight of ash oxide
Preferably, the range is . The weight average molecular weight of the ethylene/vinyl acetate/carbon oxide copolymer is preferably from 20,000 to 1,000,000.

By mixing the vinyl chloride resin and the ethylene/vinyl acetate thread copolymer described above, a highly flexible SL fat composition can be obtained. However, this composition has disadvantages in that the strength decreases significantly at high temperatures and the flexibility decreases significantly at low temperatures. Moreover, the surface of the molded product obtained from the resin composition had a drawback that it had a high viscosity and a high self-adhesion.

The present inventors have discovered that a particular block copolymer has excellent compatibility with the composition, and all of the above problems are solved. The block copolymer used in the wood invention is represented by the formula A-B-A. In this formula, the styrenic polymer of part A is styrene, α-methylstyrene, etc.
In addition, as the 8-part dibutadiene polymer, ---
It may be any polymer or the like. 1 liter of these dienes
The weight average molecular weight of the l=h combined portion is preferably in the range of 10,000 to 100,000.

The styrene polymer 1 is connected to both sides of the B section to form the A section. The weight average molecular weight of the styrene polymer portion on one side is preferably in the range of 2,000 to 50,000.

The composition ratio of the styrene polymer and the diene thread polymer in the Glock polymer is preferably in the range of 5:95 to 30:70 in terms of weight ratio.

Further, it is preferable that the degree of polymerization #i of the block polymer as a whole is in the range of 10,000 to 500,000.

The weight ratio of the vinyl chloride thread resin and the ethylene/vinyl acetate thread copolymer is t-tioo:5 to 100:2.
Preferably, it is in the range 00.

The amount of the block copolymer used per 100 parts by weight of the mixture of the vinyl chloride resin and the ethylene/vinyl acetate copolymer is preferably in the range of 15 parts by weight to 150 parts by weight.

If the proportion of the block polymer is less than 15 parts by weight, the blocking property will be too strong, and at the same time, the film will tend to have a lower strength and lose its shape during heating, and only a molded product with poor surface heat resistance will be obtained. In addition, the ratio of the Glock polymer is 150
If it exceeds the weight part, high frequency processing becomes difficult due to a decrease in dielectric constant, and wear resistance is significantly reduced.

The above-mentioned vinyl chloride yarn 1M resin, ethylene/vinyl acetate light valve polymer, and block copolymer are mixed by ordinary melt-kneading means. For example, the kneading device comes from a mixing roll, a punch-type mixer, etc.

It is preferred to add a stabilizer to maintain the thermal stability of the composition of the invention. For example, heat stabilizers such as calcium stearate, curved lead stearate, magnesium stearate, epoxidized soybean oil, and magnesium oxide can be used.

Further, the acid-resistant other side of the phenol-based or phosphite ester yarn can be used as appropriate.

In addition, a small amount of plasticizers such as dioctyl phthalate and dioctyl adipate can be added.

The thermoplastic resin composition of the present invention is transparent and has excellent flexibility. Moreover, since it has extremely good heat resistance, it can be used in many fields where it has been difficult to use it in the past.

Particularly suitable applications include medical equipment requiring steam sterilization in an autoclave, such as blood, rags, infusion bags, catheters, blood circuits, artificial heart circuits, surgical gloves, and the like.

In addition, it can be used for leather, tableware packaging films, tape base materials, wire coating materials, insulating materials, etc.

Examples Polyvinyl chloride with a degree of polymerization of 1400 as a vinyl chloride thread resin, ethylene/vinyl acetate as a light valve polymerization polymer, A part in the formula A-B-A is a styrene polymer, 8
part is polybutadiene, and the amount ratio of styrene is 3.
A block copolymer of 0% was used.

To 100 parts by weight of polyvinyl chloride, 50 parts by weight of ethylene/vinyl acetate copolymer and 15 parts by weight of block copolymer were added, and as a stabilizer, 0.1 part by weight of calcium stearate powder and zinc stearate were added. α2 parts by weight of powder,
10 parts by weight of oxygenated soybean oil was added.

Apply the above mixture to a mixing roll, roll temperature 15
The mixture was mixed at 0° C. for 5 minutes to form a sheet. This sheet t
A sheet was produced by pressing at -160°C and a pressure of 1oo#/m.

As is clear from the performance resistance column in Table 1, the composition according to the present invention has a flexibility that is comparable to that of the conventional material 1, and has excellent oil resistance and migration properties as seen in the measured values. In particular, the durability against steam P4 in an autoclave was extremely excellent.

Example 2 Vinyl chloride resin with polymerization degree of 1070 and ethylene content
i7% by weight of vinyl chloride/ethylene copolymer, ethylene/vinyl acetate copolymer, ethylene/vinyl acetate/ash oxide ternary copolymer (ethylene vs. vinyl acetate vs.
The composition ratio of ash oxide is 64:24:12), the A part in the formula A-B-AK is a styrene polymer, the 8th part is an isoprene polymer, and the styrene drips (a block with a ratio of 14%). A press sheet was prepared using the same composition ratio and operation as in Example 1, except that the copolymer was used.

As is clear from the column of Example 2 in Table 1, the composition according to the present invention has transparency and flexibility that are comparable to those of conventional lumber, and is seen in the measured values of oil resistance and migration. It had excellent physical properties as described above, and was extremely durable when heated with steam in an autoclave.

Example 3 The rolled sheet prepared in Example 2 was cut into small pieces to form square pellets. Using these pellets, a sheet with a thickness of 0.45% was created by extrusion molding. This sheet was subjected to high-frequency sealing to create a bag having dimensions of 16c+r+ in length and 12crn in width. The following test was conducted to determine whether the bag thus prepared was suitable as an infusion container.

In order to know the analysis and safety of the components eluted from the bag material 1, the eluted material IM is specified in the Japanese Mulberry Pharmacopoeia ``General Test Methods''. Removal and hemolysis tests were conducted.

11. In order to find out whether the shredded bag can withstand autoclave steam heating, 200 me of saline was added into the bag. In this state, it was placed in an autoclave and allowed to stand in pressurized steam at 121° C. for 20 minutes.

The results are shown in Table ①. As is clear from the results in Table 11, it was found that the bags made from the compositions of the present invention were suitable for use as liquid bags.

Comparative Example: To 100 parts by weight of polyvinyl chloride with a degree of polymerization of 1400, 55 parts by weight of 1 dioctyl fluoride was added to stabilize the calcium stearate 1 part by weight. l
l! 0.2 parts by weight of lead stearate powder and 10 parts by weight of epoxidized soybean oil were added.

A sheet was prepared in the same manner as in Example 1, and various physical properties were measured. The results are shown in the Comparative Example column of Table I.

Table 1: Rice edylene/vinyl n1 acid copolymer film (75μ thick) was adhered to both sides, and after being left at 40°C for 70 hours, changes in the weight of the test sticks were measured. Representative Mototoshi Senuma

Claims (1)

[Claims] t (a) Vinyl chloride thread resin, (b) Ethylene/vinyl acetate light valve polymer, ()) Formula A-
A block copolymer represented by B-A, where A is an ethylene copolymer and B is a diene copolymer, a thermoplastic resin composition containing the above (a), (b), and (c) as acid components. thing. 2. The thermoplastic resin composition according to claim 1, wherein the vinyl chloride thread resin is a vinyl chloride/ethylene copolymer. 3. The thermoplastic resin composition according to claim 1 or 2, wherein the ethylene/vinyl acetate copolymer is an ethylene/vinyl acetate/carbon oxide copolymer.