JPS5849564B2 - Manufacturing method for vinyl chloride resin molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing polyvinyl chloride resin shaped articles, and in particular, by modifying the surface properties of the shaped articles, plasticizers and other substances inside the shaped articles can be removed. This invention relates to a method for preventing additives from migrating and oozing out onto the surface of an article over time.

PVC resin gives hard and rigid molded products when it is not mixed with a plasticizer, but its hardness can be adjusted by adding a plasticizer such as phthalate, so it is suitable for hard molded products. It is widely applied not only as a material but also as a so-called soft molded product.

In this molding process, in addition to plasticizers, stabilizers, lubricants, antioxidants, kireku, non-dripping agents, ultraviolet absorbers, Various additives and compounding agents such as antistatic agents and fillers are used for various products such as films, sheets, leather, tubes, hoses, bags, packing, and coating materials such as medical equipment, food packaging materials, and electrical wire coating materials. It is widely applied to agricultural materials, construction materials, etc.

However, for these vinyl chloride resin molded products,
There is a phenomenon in which the plasticizers and other additives contained in the product migrate to the surface of the molded product over time and ooze out, resulting in contamination of the appearance, deterioration, toxicity (hygienic safety), and It is said to have major drawbacks in terms of the following points, and there is a problem in that it is particularly limited in its application to medical and food applications.

As a countermeasure to these problems, a force method may be considered in which the surface of the molded product is treated with ionizing radiation, ultraviolet light, or chemical means, but when using this force method, heat resistance,
Although improvements such as solvent resistance, hydrophilicity, antistatic properties, and imparting printability are often used, it is not only impossible to prevent fζ oozing out of plasticizers, etc., but also due to the inherent properties of vinyl chloride resin. There are disadvantages such as the characteristics of

In other words, since the energy of ionizing radiation treatment is too strong, it may act not only on the surface but also to some extent inside the article, causing intermolecular cross-linking reactions, which can greatly affect the original properties of vinyl chloride resin. In addition, ultraviolet ray treatment has the problem of coloring due to decomposition and deterioration of the surface of the ceremonial article.

Furthermore, when chemical means are used, there are problems with corrosion of the molded product and the adhesion and durability of the treatment agent.

Attempts are being made to modify the surface of preformed products such as vinyl chloride resin by applying low-temperature plasma treatment to prevent the plasticizer inside the preformed products from migrating to the surface and oozing out. However, in this case, although the effect of low-temperature plasma treatment can be seen quite clearly in the initial stage, when a certain shaped product is used outdoors for a long time (in this case, the effect disappears orally). (There are problems with weather resistance and durability.

As a result of extensive research into this technical problem, the present inventors have found that when a vinyl chloride resin or shaped product containing a predetermined amount of an allyl group-containing compound having two or more allyl groups in the molecule is subjected to low-temperature plasma treatment. Cross-linking between molecules on the surface of the precept-shaped product can be progressed well, and this prevents the addition of plasticizers, etc. I found out that
The invention has been completed.

That is, the present invention molds a vinyl chloride resin composition containing 0.5 to 50 parts by weight of an allyl group-containing compound having two or more allyl groups in the molecule per 100 parts by weight of the vinyl chloride resin. Then, the shaped article is treated with low-temperature plasma of a gas that does not have plasma polymerizability under a pressure of 0.001 Torr to 10 Torr to produce a vinyl chloride resin resin article with excellent weather resistance and durability. Manufacturability method for shaped products {This is related to this method.

The present invention will be explained in detail below.

The vinyl chloride resin used in the present method of the present invention may be either polyvinyl chloride or a copolymer mainly composed of vinyl chloride. In this case, the comonomer copolymerized with vinyl chloride includes vinyl ester, Examples include vinyl ether, acrylic acid or methacrylic acid and its esters, maleic acid or fumaric acid or its anhydride and its ester, aromatic vinyl compounds, vinylidene halides, acrylonitrile or methacrylonitrile, and olefins such as ethylene and propylene. be done.

In addition, an allyl group-containing compound is used as an essential component, and it is noteworthy that it has the effect of promoting cross-linking reactions on the surface of molded products through low-temperature plasma treatment, and that this oozing-preventing effect lasts for a long time. benefits are provided.

This prevents the oozing of plasticizers, etc., eliminates the amount of plasticizer used, and is also effective in improving the flexibility of the molded product and improving the smoothness and aesthetic appearance of the surface of the molded product.

Allyl group-containing compounds used for this purpose include:
Examples include diallyl phthalate, diallyl fumarate, tetraallyloxyethane, triallyl cyanurate, triallyl isocyanurate, and the like.

It is necessary to use the allyl group-containing compound in a range of 0.5 to 50 parts by weight per 100 parts by weight of the vinyl chloride resin, and if this is too small, the effect of the low-temperature plasma treatment described above will be reduced. Furthermore, if the amount is too high, it becomes impossible to obtain a molded product having the performance inherent to vinyl chloride resin.

The vinyl chloride resin composition used in the force method of the present invention is
In addition to containing the allyl group-containing compound described above as an essential component, it also contains various necessary additives and compounding agents.

For example, diethyl phthalate, di-2 phthalate, etc. are used as plasticizers to adjust the flexibility and hardness of certain shapes.
- Phthalate esters such as ethylhexyl and dinonyl phthalate, trimellitic acid esters such as trimethyl trimellitate and trioctyl trimellitate, aliphatic dibasic acid esters such as dioctyl adipate, diisodecyl adipate, and dioctyl azelaate, oleic acid butyl,
Examples include fatty acid esters such as methyl acetyl ricinolate and chlorinated fatty acid methyl, and plasticizers such as ethyl phthalyl ethylene glycolate, diethylene glycol dibenzoate, and tributyl acetyl citrate.

In addition, additives used to improve properties such as heat resistance, lubricity, and stability include calcium stearate, zinc stearate, lead stearate, barium stearate,
Consisting of metal salts of carboxylic acids such as cadmium stearate, organotin compounds such as tribasic lead sulfate, dibasic lead phosphite, dibutyltin dilaurate, di-n-octyltin maleate, and di-n-octyltin mercapquid. Stabilizer: Ester type such as butyl stearate,
fatty acid amides, such as ethylene bisstearamide;
Lubricants made of higher fatty acids and their esters, or polyethylene wax; other various additives used in the formulation of vinyl chloride resins, such as fillers, antioxidants,
Examples include ultraviolet absorbers, antistatic agents, antifogging agents, pigments, and dyes.

The vinyl chloride resin composition used in the force method of the present invention includes:
For the purpose of improving the physical properties of the shaped article, an elastic polymer rubber may be blended, and examples of the elastic polymer include ethylene-vinyl acetate copolymer, acrylonitrile-butadiene copolymer, and styrene-acrylonitrile copolymer. , ethylene propylene elastomer, ethylene-propylene diene elastomer, etc.

In addition, these are 5 parts per 100 parts by weight of vinyl chloride resin.
It is desirable to use the compound in an amount of 0 parts by weight or less.

In the method of the present invention, the vinyl chloride resin composition obtained in this way is first shaped into a molded article, but this shaping method can be performed by extrusion, injection molding, calendar molding, inflation molding, compression molding. Shape, etc., may be any method conventionally used for molding of vinyl chloride resin, and there are no particular restrictions on the type or shape of the molded product.

Next, the shaped article is subjected to low-temperature plasma treatment, and the treatment method is to treat the shaped article under a pressure of 0.001 Torr to 10 Torr (here, the shaped article is treated with low-temperature plasma of a gas that does not have plasma polymerizability. The plasma generation conditions at this time include, for example, 1 3.5 6M between the electrodes.
Hz, 10 to 500 W of power should be applied,
Sufficient results can be obtained with either polar discharge or electrodeless discharge.

The plasma processing time varies depending on the applied voltage, but generally a few seconds to several tens of minutes is sufficient.

In addition, there are other types of plasma treatment in addition to the above-mentioned force method.
For example, the discharge frequency band can be low frequency, microwave, direct current, etc., and the plasma generation mode can be selected from glow discharge, corona discharge, spark discharge, silent discharge, etc.

In addition to external electrodes, the electrodes may also be internal electrodes, coil type, capacitive coupling, or inductive coupling.

However, whatever force method is used, it must be ensured that the surface of the material does not change in quality due to discharge heat.

Gases that do not have plasma polymerizability include helium, neon, argon, nitrogen, nitrous oxide, nitrogen dioxide, oxygen,
Examples include air, carbon monoxide, carbon dioxide, hydrogen, chlorine, hydrogen chloride, sulfur dioxide gas, and hydrogen sulfide, and these gases may be used alone or in combination.

The gas pressure of these gases in the plasma generator is 0
．． By adjusting the pressure to between 0.011-L and 10 Torr (preferably between 0.011-L and 1 Torr), the desired plasma can be generated satisfactorily.

By plasma-treating the molded product in this way,
The phenomenon in which additives such as plasticizers ooze out from the surface of the shaped product is completely suppressed, and the formed surface treatment layer (barrier layer) is highly flexible, and the crosslinking density is appropriately controlled. Therefore, the heat-sealability and durability are excellent, and even when the molded product is used outdoors for a long period of time, the barrier layer does not break and fully demonstrates its function, making it a remarkable durable molding. Goods can be obtained.

Furthermore, this plasma-treated shaped product exhibits excellent surface properties such as hydrophilicity, antifouling properties, oil resistance, and chemical resistance.

Next, examples of the present invention will be given.

Example 1 A mixture consisting of 100 parts by weight of vinyl chloride resin (TK-1300, trade name manufactured by Shin-Etsu Chemical Co., Ltd.), 50 parts by weight of DOP, 1.5 parts by weight of calcium stearate, and 1.5 parts by weight of zinc stearate was heated at 160°C. Roll kneading was carried out for 10 minutes, and the mixture was pressed at 165°C to a thickness of 0. A 5 mm sheet was prepared.

This is designated as sample A-1.

Further, a mixture containing 5 parts by weight of triallyl cyanurate was mixed and press-molded under the same conditions as above to a thickness of 0. A 5 mm sheet was prepared.

This is designated as sample B-1. Above samples A-1 and B-1
Each sheet was set in a plasma generator, the pressure was adjusted and maintained at 0.4 Torr while carbon monoxide gas was passed under reduced pressure, and a high frequency of 13.56 MHz, 150 W was applied to discharge. By doing so, plasma was generated and the sheet surface was treated for 10 minutes.

The respective sheets subjected to plasma treatment in this manner are referred to as A-2 and B-2.

For each of the above samples, the initial amount of n-hexane extracted and the amount of n-hexane extracted after forced deterioration using a weather meter were measured, and the results were as follows.

Method for measuring the amount of n-hexane extracted: A sample sheet was set at the bottom of a 100 ml cylindrical extraction container, the surface of this 26-layer was brought into contact with 501 Ill of n-hexane, and the mixture was shaken in a 37°C water bath for 2 hours. Then, the amount of plasticizer (DOP) extracted into n-hexane was quantitatively analyzed by gas chromatography.

Weather meter f forced deterioration test method; Standard Sunshine Weather meter WESUN HC
100 hours or 500 hours using a mold (manufactured by Toyo Rika)
Forced deterioration over time.

Example 2 100 parts by weight of vinyl chloride resin (TK-1 300),
A formulation consisting of 50 parts by weight of DOP, 1.5 parts by weight of calcium stearate, and 1.5 parts by weight of zinc stearate was
Roll kneading was carried out at 60°C for 10 minutes, and this was press-formed at 165°C to a thickness of 0. A 5-mat sheet was created.

This is designated as sample A-1. Further, 10 parts by weight of triallyl isocyanurate was added to the above mixture, and the mixture was cross-wired and press-molded under the same conditions as above to a thickness of 0. 5
A sheet of mm was produced.

This is designated as sample B-1. Above samples A-1 and B-1
1. Set each sheet in a plasma generator, and adjust and maintain the pressure at 0.8 torr f while venting carbon monoxide and argon mixed gas (10:90) under reduced pressure.13. 5
Plasma was generated by applying a high frequency of 6 MHz and 300 W to generate a discharge, and the sheet surface was treated for 5 minutes.

Each sheet processed in this way (A-2)
and B-2.

For each sample above, the initial amount of n-hexane extracted and the n- after forced deterioration using a weather meter were measured in the same manner as in the previous example.
The amount of hexane extracted was measured, and the results were as follows.

Example 3 100 parts by weight of vinyl chloride resin (TK-1300), DO
P50 parts by weight, calcium stearate 1.5 parts by weight,
160% of a formulation consisting of 1.5 parts by weight of zinc stearate
The mixture was roll-kneaded at 165° C. for 10 minutes and then pressed at 165° C. to form a sheet with a thickness of 0.5 mm.

This is designated as sample A-1. In addition, 10 parts by weight of triallyl cyanurate was added to the above formulation f and the mixture was kneaded and press-molded under the same conditions as above to prepare a sheet with a thickness of 0.5 mm.

This is designated as sample B-1. Above samples A-1 and B-1
Set each sheet in a plasma generator, adjust and maintain the pressure at 0.15 torr while venting carbon monoxide gas under reduced pressure, and apply a high frequency of 13.56 MHz, 500 W to discharge. This generated plasma and treated the sheet surface for 5 minutes.

The sheets processed in this way are referred to as A-2 and B-2.

The initial n-hexane extraction amount and the n-hexane extraction amount after outdoor exposure were measured for each of the above samples, and the results were as follows.

Reference example 100 parts by weight of vinyl chloride resin (TK-1300), DO
P50 parts by weight, calcium stearate 1.5 parts by weight,
A mixture of 1.5 parts by weight of zinc stearate and 5 parts by weight of dibenzoyl peroxide and 0.4 parts by weight of diallyl phthalate as a crosslinking agent for vinyl chloride resin is used as c-L dicumyl peroxide. d-1 contains 10 parts by weight of divinyl adipate, e-1 contains 10 parts by weight of divinylbenzene, and f-1 contains 10 parts by weight of divinylbenzene. A mixture containing 10 parts by weight of methyl methacrylate and a mixture containing 10 parts by weight of g-L allyl maleate were designated as h-1.
Roll kneading was carried out at 165°C for 10 minutes, and the mixture was press-molded at 165°C to a thickness of 0. A 5 mm sheet was prepared.

These sheets (samples) were sequentially labeled C-1 and D-1.
, E-1, F-1, G-1, H-1.

The above sheet was set in a plasma generator, and the pressure was adjusted and maintained at 0.8 torr while passing carbon monoxide and argon mixed gas (10:90) under reduced pressure.1 3.5 6
Plasma was generated by applying high-frequency power of 300 W of MHz and causing discharge, and the sheet surface was treated for 5 minutes.

In this way, the strained and processed sheets are processed in the following order (C-2,
D-2, E-2, F-2, G2, and H-2.

For each sheet above, the initial n-hexane extraction amount,
The amount of n-hexane extracted after forced deterioration by weather makeup was measured, and the results were as follows.

Claims (1)

[Claims] 1. Allyl group-containing compound having 2 or more allyl groups in the molecule per 100 parts by weight of vinyl chloride resin.
Forming a vinyl chloride resin composition containing 50 parts by weight, and then treating the formed product with low-temperature plasma of a gas that does not have plasma polymerizability under a pressure of 0.001 Torr to 10 Torr. A manufacturing method for vinyl chloride resin molded products characterized by: