JPS5851008B2 - Grafting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly uses a graft copolymer having a hydrocarbon polymer as the main chain and grafting side chains mainly composed of diacyloxystyrene and/or dihydroxystyrene, and a hydrocarbon polymer as the main chain. The present invention relates to a method for producing a graft copolymer in which a chain is grafted with a side chain mainly composed of diacyloxystyrene and/or dihydroxystyrene and a diene compound.

One purpose of the present invention is to provide a method for producing a novel graft copolymer having excellent properties, and another purpose is to improve the adhesiveness, dyeability, and reactivity of hydrocarbon polymers with other compounds. The purpose is to provide a method for improving inferior properties.

As a result of various studies for the above purpose, the present inventors have found that diacyloxystyrene and/or dihydroxystyrene can be graft-polymerized onto a hydrocarbon polymer by a so-called pre-irradiation method or a simultaneous irradiation method using ionizing radiation. It has been found that mixtures of diacyloxystyrene and/or dihydroxystyrene and diene compounds can also be cografted onto hydrocarbon polymers in a similar manner.

The hydrocarbon polymer grafted with diacyloxystyrene and/or dihydroxystyrene of the present invention has improved adhesion, dyeability, reactivity with other compounds, etc., which are disadvantages of hydrocarbon polymers, and has improved redox properties. It is a useful substance that has many uses such as resins, molecular or ion sieving membranes, diaphragms for electrolytic cells, and electrodialysis membranes.

Furthermore, the hydrocarbon polymer in which diacyloxystyrene and/or dihydroxystyrene and a diene compound are co-grafted according to the present invention has a partially crosslinked network structure due to the co-grafted diene compound, and therefore does not have the above properties. In addition, it has been found that further improvements in mechanical and chemical properties are provided.

Therefore, the gist of the present invention is to add a monomer containing diacyloxystyrene and/or dihydroxystyrene as a main component or a monomer mixture containing diacyloxystyrene and/or dihydroxystyrene and a diene compound as a main component to a hydrocarbon polymer. The present invention relates to a method for producing a graft copolymer, characterized in that graft or cograft polymerization is carried out using.

Hydrocarbon polymers used in the present invention include aliphatic polymers such as polyethylene, polypropylene, and polybutene, aromatic polymers such as polystyrene and poly-α-methylstyrene, and alicyclic polymers such as polyvinylcyclohexane. Alternatively, copolymers of these may be used.

These polymers may be in the form of powder, fiber, film, or any other form.

Further, diacyloxystyrene to be subjected to graft polymerization is represented by the general formula.

The position of the substituent can be arbitrary, and R is a linear or branched aliphatic, alicyclic, or aromatic hydrocarbon group having 1 to 20 carbon atoms, such as diacetoxystyrene, diacetoxystyrene, Propionyloxystyrene, dibutyroyloxystyrene, dibenzoyloxystyrene, etc. are suitable.

Most commonly diacetoxystyrene is used.

The dihydroxystyrene to be subjected to graft polymerization may be any isomer having a different substituent position, or may be a mixture thereof.

Furthermore, as the diene compound to be subjected to graft polymerization, compounds containing two or more polymerizable double bonds in the molecule are used, such as divinylbenzene, isoprene, phtadiene, cyclopentadiene, ethylidenenorbornene, and acrylic acid. Alternatively, diol esters of methacrylic acid, divinyl esters of adipic acid, etc. are used.

Among them, divinylbenzene and isoprene are preferably used.

Divinylbenzene has three isomers, ortho, meta, and para, and any of these isomers can be used, and a mixture of these is generally used.

In addition, divinylbenzene, which is commonly obtained as a commercial product, contains ethylvinylbenzene in addition to divinylbenzene.
Although it is often a mixture containing about 5% by weight, this mixture may be subjected to the reaction as it is.

In the present invention, when a monomer mixture containing diacyloxystyrene and/or dihydroxystyrene and a diene compound as main components is co-grafted onto a hydrocarbon polymer, diacyloxystyrene and a diene compound are used as the monomers to be grafted. They may be mixed and subjected to a reaction, dihydroxystyrene and a diene compound may be mixed and subjected to a reaction, or diacyloxystyrene, dihydroxystyrene and a diene compound may be mixed and subjected to a reaction. .

The mixing ratio of diacyloxystyrene and/or dihydroxystyrene and the diene compound can be selected arbitrarily, and the physical properties of the graft copolymer obtained change depending on the mixing ratio, so the physical properties of the desired graft copolymer can be changed. Although the value should be selected according to the value of 0 diacyloxystyrene and/or dihydroxystyrene/diene compound, a range of 200/1 to 1/1 is usually appropriate, and a value of 50/1 to 2/1 is suitable. A range is preferred.

These diacyloxystyrene and/or dihydroxystyrene or a mixture of these and a diene compound are dissolved in an organic solvent and subjected to graft polymerization as a solution. An organic solvent is used that uniformly dissolves both this and the diene compound, but does not dissolve the hydrocarbon polymer.

For example, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and butyl acetate, alcohols such as methyl alcohol, ethyl alcohol, flobyl alcohol, and methyl alcohol, ethers such as tetrahydrone and dioxane, and aromatic hydrocarbons such as benzene and toluene. , n-heptane or cyclohexane or mixtures thereof are suitable.

Among these, those that swell hydrocarbon polymers are preferably used.

In addition, the concentration of monomer in the solution does not need to be particularly limited, but a range of 0.1 to 80% by weight is appropriate, and 5 to 5% by weight.
A range of 0% by weight is preferred.

The cograft polymerization of the present invention is carried out using ionizing radiation, in which scavenging radicals or polymer peroxides are generated on the hydrocarbon polymer by irradiation with ionizing radiation, and diacyloxystyrene and/or dihydroxy A side chain consisting of styrene or styrene and a diene compound is formed.

When a diene compound is also used, partial crosslinking due to the diene compound in the side chain also occurs.

Further, when an unsaturated compound such as ethylvinylbenzene is present in the monomer mixture to be co-graft polymerized, such unsaturated compound is also co-graft polymerized and contained in the side chain.

The presence of some unsaturated compounds such as those mentioned above other than diacyloxystyrene, dihydroxystyrene and diene compounds is permissible.

Graft polymerization methods using ionizing radiation include a pre-irradiation method in which the main chain polymer is irradiated with ionizing radiation in the absence of the monomer to be grafted and then brought into contact with the monomer, and a pre-irradiation method in which the polymer is brought into contact with the monomer. Although there is a simultaneous irradiation method in which ionizing radiation is irradiated in coexistence, either method may be used in the method of the present invention.

Various types of radiation can be used as the ionizing radiation, such as gamma rays, X-rays, electron beams, alpha rays, or mixed radiation thereof.

The intensity of the ionizing radiation used, that is, the dose rate, is approximately 10
3 to 1011 rad per hour is suitable.

For electron beams, high dose rates of 109 to 1011 rand/hour can be effectively used.

It is particularly effective to use an electron beam generated from an electron beam accelerator, since it is possible to irradiate a high dose in a short period of time.

The total radiation dose required for graft polymerization is usually 105 rad or more.

The temperature during radiation irradiation does not need to be particularly limited, but room temperature or lower is appropriate.

In carrying out the present invention, when using a pre-irradiation method, a hydrocarbon polymer is irradiated with ionizing radiation in a vacuum, a nitrogen stream, or in air, and then the hydrocarbon polymer is irradiated with diacyloxystyrene and/or Each monomer is co-grafted onto the hydrocarbon polymer by immersing it in an organic solvent solution containing dihydroxystyrene or dihydroxystyrene and a diene compound.

At this time, the graft polymerization reaction can proceed satisfactorily at room temperature or lower when irradiation with ionizing radiation is carried out in a vacuum or in a nitrogen stream, and may also be carried out at a temperature higher than room temperature.

When irradiation with ionizing radiation is carried out in air, the graft polymerization reaction is preferably carried out at a temperature of 60°C or higher.

Industrially, a method of pre-irradiation with radiation in air or a nitrogen stream is advantageous.

In addition, when using the simultaneous irradiation method, a hydrocarbon polymer is immersed in an organic solvent solution containing diacyloxystyrene and/or dihydroxystyrene or a diene compound therewith, and ionizing radiation is irradiated thereon to produce a hydrocarbon polymer. Each monomer is co-grafted to form a combination.

Room temperature is sufficient for the reaction temperature, but it may be higher.

The ratio of diacyloxystyrene and/or dihydroxystyrene or a monomer mixture of these and a diene compound to the hydrocarbon polymer to be subjected to the graft polymerization reaction is changed as appropriate depending on the desired grafting ratio of the target graft copolymer. be able to.

The graft copolymer thus produced is optionally washed with an organic solvent such as methanol, ethanol, alcohol such as propyl alcohol, acetone, a ketone such as methyl ethyl ketone, an aromatic hydrocarbon such as benzene, toluene, or a mixture thereof. do.

Furthermore, in the graft copolymer having a side chain containing diacyloxystyrene, the acyloxy group in the side chain can be converted to a hydroxyl group by hydrolysis treatment, if necessary.

This hydrolysis treatment, similar to the commonly practiced hydrolysis of phenol esters, is extremely easier than the hydrolysis of primary alcohol esters, and can be easily carried out under mild conditions.

That is, using an acid or a base as a catalyst, the graft copolymer is placed in an aqueous solution or a mixed solution of water and a water-soluble organic solvent containing these catalysts to carry out a hydrolysis reaction of the acyloxy groups in the side chains.

Since the hydrolysis reaction is mainly carried out in a heterogeneous system, a water-soluble organic solvent such as alcohol or ketone and water are used to increase the affinity between the substrate and the catalyst and to dissolve the organic acid released when an acidic catalyst is used. Preferably, it is carried out in a mixture with.

A suitable reaction temperature for hydrolysis is 50 to 100°C.

In this hydrolysis treatment, the hydrolysis rate of the acyloxy group in the side chain can be arbitrarily changed.

According to the present invention, the present invention has a side chain mainly consisting of diacyloxystyrene and/or dihydroxystyrene or these and a diene compound, and when a diene compound is also used, the diene compound contained in the side chain partially It is possible to obtain a novel graft copolymer whose main chain is a hydrocarbon polymer that has been crosslinked and reticulated.

This graft copolymer has the excellent mechanical properties of hydrocarbon polymers, and also has suitable functional groups, so it does not have adhesion, which is a drawback of hydrocarbon polymers, and is susceptible to dyeing or reaction with other compounds. In particular, graft copolymers with dihydroxystyrene-containing side chains have excellent properties and are used as raw materials for reactive polymers. It is a useful substance with many uses.

A graft copolymer obtained by cografting diacyloxystyrene and/or dihydroxystyrene, which is one of the products of the present invention, and a diene compound onto a hydrocarbon polymer is a
Alternatively, it has better mechanical properties and chemical properties than a graft copolymer obtained by grafting only dihydroxystyrene.

The present invention will be further explained below with reference to Examples.

Example 1 Glass H-type cell (diameter 10 mm, wall thickness 0.5 mm)
) with a thickness of 0.1 m thoroughly cleaned with acetone.
Insert a polyethylene film of 3.5 m and 3.4 m of polyethylene film on the other leg.
- A monomer mixture of diacetoxystyrene and divinylbenzene (divinylbenzene content: 55 wt%, remainder mainly ethylvinylbenzene) in a weight mixing ratio of 9 (3,4-diacetoxystyrene/divinylbenzene-9) A mixed solvent of twice the weight of benzene and acetone (
A solution dissolved in benzene/acetone (3) at a volume ratio was added, sufficiently degassed by a freeze-thaw method in a vacuum, and then melt-sealed.

Freeze the monomer solution, cover it thoroughly with a lead plate, and use an electron beam accelerator with the entire H-type cell cooled to -30°C.
The polyethylene film in a vacuum of 30 Mrad was irradiated with an electron beam at an accelerating voltage of 1.5 MeV.

After irradiation, the monomer solution was transferred to the film side and allowed to react at room temperature for 24 hours.

After the reaction, the film was opened, taken out, thoroughly washed with benzene and acetone, and dried under reduced pressure until it reached a constant weight.

The total grafting rate calculated from the difference in weight of the film before and after reaction was 1.05%.

The weight of the obtained film did not change even after repeated extraction with acetone and benzene.

The film obtained as described above was attached to a cooling tube.
00ml flask, added 501fLl of concentrated hydrochloric acid-methanol solution with a mixing ratio of 1:4 in terms of volume, and heated on a water bath for 30 minutes.

The grafting ratio of 3,4-diacetoxystyrene alone calculated from the difference in weight of the film before and after the hydrolysis treatment was 85.
%, and the grafting rate of divinylbenzene was determined to be 20%.

Example 2 A graft polymerization reaction was carried out in the same manner as in Example 1, except that a polypropylene film having a thickness of Q and 1 mm was used as the backbone polymer.

The total grafting rate calculated from the weight increase of the obtained film was 109%, and as a result of hydrolyzing this graft film, 3,4-diacetoxystyrene and divinyl were calculated from the difference in weight of the graft film before and after treatment. The grafting rate of benzene is 87% and 22%, respectively.
%Met.

Example 3 A graft polymerization reaction was carried out in the same manner as in Example 1 except that polypropylene powder was used as the backbone polymer.

The total grafting rate calculated from the weight increase of the obtained grafted powder was 62%, and as a result of further hydrolysis treatment of this grafted powder, 3,4-diacetoxystyrene and The grafting rates of divinylbenzene were 44% and 18%, respectively.

Example 4 A polyethylene film having a thickness of 0.1 mm was cooled to -20°C and irradiated with an electron beam at 30 Mrad in air.

Next, this film was placed in a glass ampoule, and into the ampoule was added 2 ml of a monomer mixture of 3,4-diacetoxystyrene and divinylbenzene in a weight mixing ratio of 9.
A solution dissolved in a mixed solvent of twice the weight of benzene and acetone (volume ratio: benzene/acetone: 3) was poured, and the mixture was sufficiently degassed by a freeze-thaw method in vacuo and then sealed.

This ampoule was placed in a constant temperature bath at 70°C and reacted for 3 hours.

After the reaction, the ampoule was opened and the film was taken out, and the film was thoroughly washed with benzene and acetone and dried under reduced pressure until it reached a constant weight.

The total grafting rate calculated from the weight increase of the obtained graft film was 28%.

As a result of hydrolyzing this graft film in the same manner as in Example 1, the weight difference between the graft film before and after the treatment was 3.
- The grafting rates of 4-diacetoxystyrene and divinylbenzene were 20% and 8%, respectively.

Example 5 1.1. Using a cobalt-60 radiation source instead of an electron beam at room temperature. A graft polymerization reaction was carried out in the same manner as in Example 1 except that γ-rays of X 105 rad/hr were irradiated for 24 hours.

The total grafting rate calculated from the weight increase of the obtained grafted film was 72%.

As a result of hydrolysis treatment of this graft film in the same manner as in Example 1, the grafting ratios of 3,4-diacetoxystyrene and divinylbenzene determined from the weight difference of the graft film before and after treatment were 51% and 21%, respectively.
Met.

Example 6 A graft polymerization reaction was carried out in the same manner as in Example 1 except that 3,4-dihydroxystyrene was used instead of 3,4-diacetoxystyrene.

The total graft ratio calculated from the weight increase of the obtained graft film was 4.5%.

From the acetyl value determined by acetylating this graft film with an acetic anhydride-sodium acetate system, the grafting rate of 3,4-dihydroxystyrene was 3.7%, and the grafting rate of divinylbenzene was 0.8%.

Example 7 A graft polymerization reaction was carried out in the same manner as in Example 1 except that isoprene was used in place of divinylbenzene.

The total grafting rate calculated from the weight increase of the obtained grafted film was 23%.

As a result of hydrolysis treatment of this graft film in the same manner as in Example 1, the grafting ratios of 3,4-diacetoxystyrene and isoprene determined from the difference in weight of the graft film before and after treatment were 22% and 1%, respectively. .

Example 8 A graft polymerization reaction was carried out in the same manner as in Example 1 except that divinylbenzene was not used.

The total grafting rate calculated from the weight increase of the obtained graft film was 86%.

Example 9 A graft polymerization reaction was carried out in the same manner as in Example 1 except that divinylbenzene with a content of 55% was substituted with divinylbenzene with a content of 90%.

The total grafting rate calculated from the weight increase of the obtained grafted film was 112%.

As a result of hydrolyzing this graft film in the same manner as in Example 1, the grafting ratios of 3,4-diacetoxystyrene and divinylbenzene determined from the difference in weight of the graft film before and after treatment were 83% and 29%, respectively. .

Example 10 A polyethylene film with a thickness of 0.1 mm was placed in a glass ampoule, and the ampoule was further filled with a mixture of 3.4 diacetoxystyrene and divinylbenzene in a weight mixing ratio of 9 (3.
A mixture of 4-diacetoxystyrene/divinylbenzene-9) was mixed with a mixed solvent of 9 times the weight of benzene and acetone (
A solution dissolved in benzene/acetone-3) was added in a volume ratio, and after sufficient deaeration by a freeze-thaw method in a vacuum, the solution was melt-sealed.

This was done using a cobalt 600 radiation source at room temperature to
05 rad/hr γ-rays were irradiated for 24 hours.

Thereafter, the film was taken out from the ampoule, thoroughly washed with benzene and acetone to remove a by-product copolymer of 3,4-diacetoxystyrene and divinylbenzene, and then air-dried.

The total grafting rate calculated from the weight increase of the obtained grafted film was 75%.

As a result of hydrolyzing this graft film in the same manner as in Example 1, the grafting ratios of 3,4 diacetoxystyrene and divinylbenzene, determined from the difference in weight of the graft film before and after the treatment, were 54% and 21%, respectively. Ta.

Claims (1)

[Scope of Claims] 1. A method for producing a graft copolymer, which comprises graft polymerizing a monomer containing diacyloxystyrene and/or dihydroxystyrene as a main component to a hydrocarbon polymer using ionizing radiation. 2. A method for producing a graft copolymer, which comprises co-graft polymerizing a monomer mixture containing diacyloxystyrene and/or dihydroxystyrene and a diene compound as main components onto a hydrocarbon polymer using ionizing radiation.