JPH0796585B2 - Vinyl copolymer with excellent antistatic properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a vinyl copolymer having excellent antistatic properties.

The vinyl polymerization type polymer material is widely used as an industrial material, but usually has a strong hydrophobic property and, as a result, has a property of being easily charged. The property of being easily charged is a major obstacle in the process of manufacturing and processing the vinyl polymerization type polymer material and in using these products.

The present invention can reduce the above obstacles,
The present invention relates to a vinyl copolymer having excellent antistatic properties.

<Conventional technology and its problems> Conventionally, as with many hydrophobic polymer materials, even in vinyl polymer materials, conductive materials such as carbon and conductive metal powder or surfactants are used as the polymer. Attempts have been made to eliminate various obstacles due to static electricity by kneading the material or applying it to the surface thereof.

However, the method of using a conductive material such as carbon or conductive metal powder has a large amount of use, and a complicated operation is required to uniformly knead into a polymer material, and thus the transparency of the obtained product is obtained. There is a problem that the usable range is extremely narrow and limited due to difficulty and high price. Since the means using a surfactant is easy to handle, it is widely used for kneading and surface coating, but this means that the antistatic effect is easy due to aging, friction, washing, etc. However, there is a problem that durability is insufficient.

On the other hand, a vinyl copolymer in which a vinyl monomer having a hydrophilic group in the molecule is copolymerized to impart durable antistatic property is also proposed. However, each of these conventional proposals has the following problems.

For example, in the case of a vinyl monomer having a quaternary ammonium salt group (Japanese Patent Publication No. 58-15471), it generally gives a relatively good antistatic property, but its thermal stability is insufficient and the resulting copolymer The combined product is easily colored, and when molding or the like is performed using these copolymers, color deterioration is apt to progress along with the thermal decomposition reaction, and in addition to deterioration of various physical properties, charging The preventive effect also decreases.

In the case of a monomer having a polyoxyalkylene group as a hydrophilic atom group (JP-A-56-139516), in order to obtain a desired antistatic property, the copolymerization ratio is increased as compared with that having an ionic group. The level of antistatic effect that is necessary and nevertheless attainable is inherently low. As a result of increasing the copolymerization ratio, the heat distortion temperature and the surface hardening are lowered, and it becomes easy to swell with hot water or an organic solvent. In the end, the applicable range as a polymer material becomes extremely narrow.

In the case of a vinyl monomer having an anionic group, for example, an alkali metal sulfonate base, it is a substance having extremely strong polarity like other anionic monomers, and therefore has a solubility in water or some polar solvents. However, on the contrary, it is hardly compatible with general water-insoluble monomers used for vinyl polymerization, such as styrene, methyl methacrylate, and vinyl acetate.
Further, it is only soluble in a limited range or insoluble in general organic solvents used for solution polymerization using these water-insoluble monomers. Therefore, the method of copolymerization is considerably limited, and even when emulsion polymerization or suspension polymerization is performed, the copolymerizability with other vinyl monomers is low, and it is difficult to increase the copolymerization ratio.

<Problems to be Solved by the Invention and Means for Solving the Problems> The present invention provides a new vinyl copolymer which solves the above-mentioned conventional problems.

However, in view of the above-mentioned circumstances, the present inventors have earnestly studied to obtain a vinyl copolymer having good heat resistance and having a durable antistatic property that does not deteriorate the effect even by washing or the like. As a result, it was found that a vinyl copolymer obtained by copolymerizing an ethylenically unsaturated monomer having a specific phosphonium sulfonate group and a specific vinyl monomer at a predetermined ratio is properly suitable. The invention has been reached.

That is, the present invention comprises 0.2 to 10 mol% of an ethylenically unsaturated monomer having a phosphonium sulfonate group represented by the following general formula (1), a (meth) acrylic acid ester, a vinyl aromatic hydrocarbon and acrylonitrile. The present invention relates to a vinyl copolymer having excellent antistatic properties, which is obtained by copolymerizing one kind or two or more kinds of vinyl monomers selected from the above at a ratio of 99.8 to 90 mol%.

General formula (1): [However, A is an organic group having an α, β unsaturated double bond. R ¹
To R ⁴ are the same or different, a hydrocarbon group having 1 to 18 carbon atoms or a hydrocarbon group having a substituent having 1 to 18 carbon atoms. In the present invention, the ethylenically unsaturated monomer represented by the general formula (1) is composed of an organic sulfonate anion having an α, β unsaturated double bond and an organic phosphonium cation.

Examples of the organic sulfonate anion include α, β alkenyl sulfonates such as vinyl sulfonate, allyl sulfonate and methallyl sulfonate, vinyl aromatic sulfonates such as styrene sulfonate and methyl styrene sulfonate, 2-acryloxyethyl sulfonate, 2-methacrylate. Roxypropyl sulfonate, 3-
Acryloxy-2-hydroxypropyl sulfonate,
3-methacryloxy-2-hydroxypropyl sulfonate, 2-acrylamidoethyl sulfonate, 2-methacrylamidoethyl sulfonate, 3-N-methyl-
Examples thereof include acrylamidopropyl sulfonate and 3-N-methyl-methacrylamidopropyl sulfonate.

As the organic phosphonium cation, for example, tetramethylphosphonium, tetraethylphosphonium,
Aliphatic phosphonium such as tetrabutylphosphonium, triethylmethylphosphonium, tributylmethylphosphonium, tributylethylphosphonium, trioctylmethylphosphonium, trimethylbutylphosphonium, trimethyloctylphosphonium, trimethyllaurylphosphonium, trimethylstearylphosphonium, triethyloctylphosphonium, and tributyloctylphosphonium, Examples thereof include aromatic phosphoniums such as tetraphenylphosphonium, triphenylmethylphosphonium, triphenylbenzylphosphonium, triphenylethylphosphonium, triethylbenzylphosphonium, and tributylbenzylphosphonium. Furthermore, tetramethylolphosphonium, tri (2-cyanoethyl)
Methylphosphonium, tri (2-cyanoethyl) ethylphosphonium, tri (2-cyanoethyl) benzylphosphonium, tri (3-hydroxypropyl) methylphosphonium, tri (3-hydroxypropyl) benzylphosphonium, trimethyl (2-hydroxyethyl) phosphonium, Phosphonium having a substituent such as tributyl (2-hydroxyethyl) phosphonium can also be used.

The ethylenically unsaturated monomer represented by the general formula (1) is composed of an arbitrary combination of the organic sulfonate anion and the organic phosphonium cation as exemplified above. , A metal salt or ammonium salt of a corresponding organic sulfonate and a quaternary phosphonium salt are mixed in a solvent, and an inorganic salt produced as a by-product is washed and separated, or an organic solvent such as methanol, isopropanol or acetone is used. It can be produced by extracting the monomer. More specifically, for example, in the case of tetrabutylphosphonium styrenesulfonate, 20.6 g of sodium styrenesulfonate, 33.9 g of tetrabutylphosphonium bromide and 200 ml of water are charged into a flask and stirred at 80 ° C for 1 hour to separate as an oil layer. The target monomer that comes in is separated, washed with 50 ml of warm water, and dehydrated with an evaporator, whereby the product can be produced with a yield of about 90%.

The vinyl monomer to be copolymerized with the ethylenically unsaturated monomer represented by the general formula (1) to form the vinyl copolymer excellent in antistatic property according to the present invention is 1) methyl acrylate. , Ethyl acrylate, butyl acrylate,
Acrylic esters such as 2-ethylhexyl acrylate and N, N-dimethylaminopropyl acrylate, 2)
Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate and 2-hydroxyethyl methacrylate, 3) vinyl aromatic hydrocarbons such as styrene and methyl styrene, and / or 4) acrylonitrile.

In order to obtain good antistatic properties in the vinyl copolymer of the present invention formed by copolymerizing the ethylenically unsaturated monomer represented by the general formula (1) and the above-mentioned specific vinyl monomer, The copolymerization ratio of the ethylenically unsaturated monomer is 0.2 to 1
It is 0 mol%, preferably 0.5 to 7 mol%. As the vinyl monomer copolymerizable with the ethylenically unsaturated monomer represented by the general formula (1), a hydrophilic monomer such as 2
When -hydroxyethyl methacrylate or N, N-dimethylaminopropyl acrylate is used, it is possible to lower the copolymerization ratio of the ethylenically unsaturated monomer represented by the general formula (1), The copolymerization ratio is
If the amount is less than 0.2 mol%, the desired antistatic property cannot be obtained. On the contrary, when the copolymerization ratio of the ethylenically unsaturated monomer represented by the general formula (1) exceeds 10 mol%, the physical properties of the vinyl copolymer obtained, for example, the softening point,
Creep characteristics, swelling resistance to organic solvents, etc. tend to decrease. Therefore, the ethylenically unsaturated monomer represented by the general formula (1) determines the optimum copolymerization ratio within the range of 0.2 to 10 mol% in view of the balance between the effect of antistatic property and the physical properties. Preferably.

The form of copolymerization in the vinyl copolymer of the present invention may be random, block, graft or the like depending on the polymerization method. As the above-mentioned polymerization method, an ethylenically unsaturated monomer represented by the general formula (1) is directly dissolved in a vinyl monomer copolymerizable therewith or a low-polymerized product thereof and copolymerized in the presence of a polymerization initiator. The bulk polymerization to be carried out, solution polymerization using an organic solvent, emulsion polymerization or suspension polymerization using water as a solvent or dispersion medium, and the like are applicable. Further, the ethylenically unsaturated monomer represented by the general formula (1) is graft-polymerized in the chain or at the terminal of the vinyl polymer with respect to the vinyl polymer obtained by previously polymerizing the specific vinyl monomer. You can also do it. The present invention is also not particularly limited in terms of polymerization mode, and radical polymerization, ionic polymerization, living polymerization, etc. can be arbitrarily adopted.

Examples and the like will be given below in order to clarify the constitution and effects of the present invention, but the present invention is not limited to these examples.

<Examples, etc.> Examples 1-10, Comparative Examples 1-6 Various monomers having the monomer compositions shown in Table 1 were placed in a polymerization reaction can and uniformly dissolved. Next, 0.5 mol% of benzoyl peroxide as a polymerization initiator is added to all monomers,
The reaction was carried out at 60 ° C. for 30 minutes in a nitrogen gas atmosphere to obtain a syrup-like low polymer. In this case, in Comparative Example 4 only, the syrup-like low polymer was clouded and some precipitates were observed. In each of the examples and the other comparative examples, the syrup-like low polymerized product was uniformly transparent. The syrup-like low polymer obtained was poured into a 100 × 100 × 2 mm stainless cell and polymerized in warm water at 60 ° C. for 4 hours.
The polymerization was completed by leaving it in an oven at 0 ° C. for 2 hours. A sheet of the content was taken out from the cell, subjected to the following tests, and further evaluated and measured as described below. The results are shown in Table 1.

..Heat treatment test: 30 sheets at 150 ° C in hot air dryer
Heat treatment was performed for a minute.

.. Hot water treatment test: The sheet was immersed in hot water at 80 ° C for 1 hour and then air-dried at room temperature.

... Appearance evaluation: The sheet subjected to the heat treatment test, the sheet subjected to the hot water treatment test, and the untreated sheet were visually judged according to the following criteria.

◯: Transparent and no coloration or color turbidity was observed. Δ: White turbidity or coloration was recognized. X: Color turbidity or coloration was marked .... Surface electrical resistance: sheet subjected to hot water treatment test and untreated sheet. After being left for 24 hours in a thermo-hygrostat at 65% RH at 20 ° C, the surface electric resistance was measured.

The above symbols are the same in Table 2.

Examples 11 to 14 and Comparative Examples 7 to 9 Each monomer having the monomer composition shown in Table 2 and 1000 g of toluene as a solvent were charged in a polymerization reaction vessel and uniformly mixed. Next, 1 g of α, α′-azobisisobutyronitrile was added, and the reaction was continued in a nitrogen stream at 100 ° C. for 24 hours to complete the polymerization. After the reaction solution was cooled to room temperature, it was poured into methanol with vigorous stirring, and the polymer was precipitated and precipitated. After the precipitate was filtered off, it was dried in a vacuum drier to obtain a copolymer. The sulfur content in the obtained copolymer was analyzed and quantified by an elemental analyzer according to a conventional method,
From this result, the copolymerization mol% of the copolymerized sulfonic acid group-containing monomer (A or G in Table 2) was calculated.
A sheet having a thickness of 2 mm was prepared from the obtained copolymer with a compression molding machine, subjected to the same tests as in the above-mentioned examples, further evaluated and measured, and the results are shown in Table 2. It was

<Effects of the Invention> As is clear from the results in each table, the present invention described above has good heat resistance on the desired appearance without impairing the desired appearance, and is also deteriorated by washing or the like. There is an effect that it has excellent antistatic properties with durability that does not occur.

Claims (6)

[Claims] 1. An ethylenically unsaturated monomer having a phosphonium sulfonate group represented by the following general formula (1):
0.2-10 mol% and selected from (meth) acrylic acid ester, vinyl aromatic hydrocarbon and acrylonitrile 1
A vinyl copolymer having excellent antistatic properties, which is obtained by copolymerizing one or more vinyl monomers in a proportion of 99.8 to 90 mol%. General formula (1): [However, A is an organic group having an α, β unsaturated double bond. R ¹
To R ⁴ are the same or different, a hydrocarbon group having 1 to 18 carbon atoms or a hydrocarbon group having a substituent having 1 to 18 carbon atoms. ] 2. A-SO₃ Is styrene sulfonate or
Claim 1 which is tyl styrene sulfonate.
The vinyl copolymer having excellent antistatic properties described. 3. A-SO₃ Is acryloxyethyl sulfone
, Methacryloxypropyl sulfonate, 3-ac
Riloxy-2-hydroxypropyl sulfonate or 3
-Methacryloxy-2-hydroxypropyl sulfone
Excellent antistatic property according to claim 1
Vinyl copolymer. 4. A-SO₃ Is vinyl sulfonate, allyl
Claim to be sulfonate or methallyl sulfonate
Copolymer having excellent antistatic properties according to item 1
body. 5. A-SO₃ Is acrylamide ethyl sulfo
Nate, methacrylamide amidoethyl sulfonate, N-me
Cylacrylamidopropyl sulfonate or N-methyl
Patent contract that is methacrylamide propyl sulfonate
A vinyl copolymer having an excellent antistatic property according to the first range of the invention.
body. 6. A compound represented by the formula (1), wherein R ¹ , R ² and R ³ are the same and are an aliphatic or aromatic hydrocarbon group having 1 to 8 carbon atoms. 5. A vinyl copolymer having excellent antistatic properties according to any one of items 1.