JPS58157847A - Water-absorbing polybutadiene composition - Google Patents

Abstract

PURPOSE:The titled composition that is made by kneading a mixture of a water- absorbing synthetic macromolecular powder and a solvent solution such as a plasticizer with polybutadiene, thus being suitable for use in good-quality film, because of its higher water absorption than any conventional products and of good dispersion. CONSTITUTION:1,2-Polybutadiene, preferably containing more than 70% of 1,2- linkages, having an intrinsic viscosity of more than 0.7 in toluene at 30 deg.C and more than 5% crystallinity, is kneaded together with 0.1-80wt% of a mixture that is prepared by mixing 0.1-100pts.wt. of a solution containing a plasticizer such as phthalic ester, a dispersing agent such as paraffinic oil or polymer components dissolved in a solvent such as a rubber solution in toluene to 100pts.wt. of a water-absorbing synthetic macromolecular powder, preferably a white macromolecular substance that is prepared by dissolving maleic anhydride in acetone, dispersing polyvinyl alcohol in the resulting solution, effecting the reaction in a suspension system and neutralizing the carboxyls.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-absorbing polybutadiene composition which can be formed into a high-quality film with a high water absorption rate never seen before and is intended for use in lubrication.

It is well known that water-absorbing plastic or rubber films are made from soft resin or rubber containing finely powdered water-absorbing polymers.
Water-absorbing polymers are naturally extremely hydrophilic, so even if they are mixed directly into resin or rubber using conventional methods, it is easy to create high-quality composite materials with good dispersion. was not obtained. In addition, a solvent solution in which a plasticizer, dispersant, or polymer component is dissolved in a water-absorbing polymer consisting of a polysaccharide or its derivative and/or an ethylenically unsaturated carboxylic acid or its derivative; Recently, a method has also been developed in which a mixture of at least one type of water-absorbing plastic material is kneaded with a plastic material to obtain an improved water-absorbing plastic composite material. However, even with this method, in order to obtain a high-quality composite material with high water absorption, it is important to use fine powder with a uniform particle size of the water-absorbing polymer.
When film forming is performed, the permissible range of forming temperature conditions is narrow, and a water-absorbing polymer with greater heat resistance is required. Furthermore, conventional plastic or rubber materials used for water-absorbing plastic or rubber films composited with water-absorbing polymers are mainly
Ethylene-vinyl acetate copolymer, low density polyethylene,
Polynisder, polyamide resins, etc. have low moisture permeability, and when used as a matrix for composites, the moisture permeability of the coexisting water-absorbing polymers increases.
There was a problem that the water absorption ability of the water was not fully exhibited. In addition, soft vinyl chloride resin, which is said to have a relatively high moisture permeability, contains an extremely large amount of plasticizer (
(approximately 50%), because the migration of plasticizer is extremely large,
There are major restrictions on its usage.

The present invention has been made in view of the current situation, and includes at least one kind of plasticizer, dispersant, or polymer component dissolved in a finely powdered water-absorbing synthetic polymer in a solvent solution. It is provided with a mixture of The details are described below.

First, the fine powder water-absorbing synthetic polymers used in this invention include polyacrylates or crosslinked products thereof, saponified copolymers of vinyl esters and ethylenically unsaturated carboxylic acids or derivatives thereof, polyvinyl alcohol, Examples include water-absorbing synthetic polymers composed of ethylenically unsaturated carboxylic acids and/or their derivatives. The ethylenically unsaturated carboxylic acids or derivatives thereof that constitute the water-absorbing synthetic polymer include dicarboxylic acids such as maleic acid and fumaric acid, their anhydrides, and their derivatives such as sodium dicarboxylate, or acrylic acid and methacrylic acid. , monocarboxylic acids such as carboxylic acid/vinylbenzene, and derivatives thereof. In particular, as the fine powder water-absorbing synthetic polymer used in this invention, maleic anhydride is dissolved in acetone, polyvinyl alcohol is added and dispersed therein, and after reacting in a suspension system, the carboxyl groups are neutralized. A water-absorbing polymer in the form of a white fine powder obtained by combining the two is effective. Furthermore, most conventional water-absorbing polymers are obtained from polysaccharides such as starch, and because they use natural polymers, it is relatively difficult to obtain fine powder with a uniform particle size. On the contrary, since the present invention uses a synthetic polymer such as polyvinyl alcohol as a raw material, it has the advantage that it can be easily obtained even in the form of a fine powder with a particle size of 100 mesh or less, for example. Therefore, it is extremely convenient.

Next, as a plasticizer to be added to the above-mentioned water-absorbing polymer, a 7-talic acid ester such as dioctyl phthalate or dibutyl phthalate, or a phosphoric acid ester such as tricresyl phosphate is added, and as a dispersing agent, mineral oil is added. , paraffinic or naphthenic oils such as liquid paraffin and chlorinated paraffin, or vegetable oils such as castor oil and linseed oil, as well as organotitanium compounds such as tributyl titanate and di(dioctyl phosphate) ethylene titanate, or organosilicon Compounds etc. are used. Furthermore, as a solvent solution in which a polymer component is dissolved, natural rubber, synthetic polymer, or 1,2-polybutadiene, which is the same as the matrix polymer, is dissolved in an organic solvent such as doluol or penzol. You can also use methyl ethyl ketone, dissolved in a solvent such as acetone, etc.

Here, the blending ratio when blending at least one of a plasticizer, a dispersant, or a solvent solution in which a polymer component is dissolved with the water-absorbing polymer is as follows, per 100 parts by weight of the water-absorbing polymer. The amount is 0.1 to 100 parts by weight. This is because if the amount is less than 0.1 part by weight, sufficient dispersion effect of the water-absorbing polymer into the matrix cannot be obtained, and if it exceeds 100 parts by weight, the absorption effect of the water-absorbing polymer is inhibited, which will be described later. This is because it becomes difficult to obtain good performance of 1,2-polybutadiene when the composition of the invention is formed into a film.

However, when using a non-volatile dispersant such as paraffin oil, the amount is preferably about 0.1 to 2.0% by weight, and when using a solvent solution containing a polymer component, that is, when the solvent is Volatile like acetone, the polymer dissolved in these solvents has 1,
2-When polybutadiene, polystyrene, etc. are used, the solvent solution of the polymer component is mixed with the water-absorbing polymer.
It is preferable to volatilize and remove the solvent in advance by a reduced pressure heating drying method, or to perform extrusion kneading after one volatile solvent is suctioned and discharged from a vent hole using a vented extruder.

Furthermore, the material used as the matrix of this invention is
1,2-polybutadiene with a content of 1,2-bonds of 70% or more, an intrinsic viscosity [η] measured in toluene at 30°C of 0.7 or more, and a crystallinity of 5% or more. Something is desirable. Further, the blending ratio of such 1,2-polybutadiene and water-absorbing polymer may be set to 0.1 to 80% by weight of water-absorbing polymer to 1,2-polybutadiene. This is because if it is less than 0.1% by weight, the water absorbing ability of the water-absorbing film is insufficient when formed into a film, whereas if it exceeds 80% by weight, good film properties of 1,2-polybutadiene cannot be obtained. This is because it is difficult to get caught.

Here, the good film properties of 1,2-polybutadiene are such that, for example, in a film with a thickness of 0.1, 98 g
/m... Has a high moisture permeability for 24 hours, and has the same thickness as general-purpose resin, that is, low-density polyethylene with a moisture permeability of 25 g/m for 24 hours, or a water-absorbing plastic film of matricrene-acetic acid. Although the water permeability is more than twice that of vinyl copolymer (45 g/m2, 24 hours), by using this 1,2-polybutadiene, the water absorbing ability of the built-in water absorbing polymer is fully demonstrated. It is possible. Originally, 1,2-polybutadiene is rich in flexibility and elasticity, and can easily cope with volume expansion caused by the absorption of moisture by the built-in water-absorbing polymer. - Although polybutadiene itself has a high moisture permeability, it is not easily degraded by moisture, is harmless to the human body, and can be used for food. It has the following characteristics.

In addition, as shown in Figure 1, the water absorption capacity of a film made from a composition obtained by blending 9.2% by weight of a water-absorbing polymer with 1,2-polybutadiene as a matrix is as follows: - The value was about twice as good as that of Mo(7), which was prepared using vinyl acetate copolymer by IJ Fuchs and blended with 10% by weight of the same water-absorbing polymer and made into a film in the same way. . For example, when immersed in water for 15 minutes, the former reached a water absorption of 6.5% by weight, while the latter reached a water absorption of 3.
The water absorption rate was only 3.5% by weight, and even though the former amounted to more than 8% by weight after 60 minutes of immersion, the latter was only 3.5% by weight.
It is only a percentage by weight. Furthermore, as for the amount of moisture absorption, as is clear from FIG. 2, the one using 1,2-polybutadiene is also superior.

The composition of the present invention described above may be formed into a film by, for example, an inflation method, a die method, or any other commonly used method.
Although there are no particular restrictions, as an example, using an extruder with a diameter of 50 mm, a die diameter of 75 mm, a screw IJ-knee rotation speed of 48 rpm, a resin temperature of 150°C, and a thickness of 18 μm.
It is possible to form a film of In addition, 1,2-polybutadiene is kneaded in advance with a water-absorbing polymer mixed with at least one of a plasticizer, a dispersant, or a polymer component to form powder, granules, or pellets. It is also possible to make a molding material and re-form it into a film using an extruder equipped with a separate film-forming die.
It goes without saying that various methods such as roll mixing, vacuum heating mixing, vent extrusion kneading, twin screw extrusion kneading, etc. can be used.

When the water-absorbing polybutadiene composition of the present invention is to be used as a water-absorbing composite film, the thickness thereof is 5 μm.
For thin materials with a diameter of less than m, the average particle size of the water-absorbing polymer is usually 5 μm.
If the thickness exceeds 500 μm, these particles will protrude outside the film surface and form lumps, and the film will tear easily, making it difficult to put it to practical use.On the other hand, if the thickness exceeds 500 μm, it will resemble a sheet rather than a film. As a result, 1,2-polybutadiene loses sufficient flexibility, flexibility, and freedom to conform to arbitrary shapes, making it difficult to use it for its original purpose such as packaging, and the water permeability of 1,2-polybutadiene is , 500μm
If the film is thicker than 1,2-polybutadiene, the difference in moisture permeability from that of low-density polyethylene will gradually decrease, and the significance of using 1,2-polybutadiene will diminish, so the thickness when used as a film is 5. It is preferable to set it to 500 micrometers. However, since not only film molding but also blow molding and the like can be carried out sufficiently, the above-mentioned thickness may be used as a guide as long as water absorption, water permeability, etc. are important.

Since 1,2-polybutadiene and water-absorbing polymer each have double bonds, there is a concern that they may deteriorate due to ultraviolet rays, etc. However, in the composition of this invention, water-absorbing double bonds in polymers,
1.2-The double bonds in the side chains of polybutadiene tend to bond together when exposed to ultraviolet rays, etc., so even if it is made into a film and exposed to ultraviolet rays, etc., it will deteriorate while improving its properties as a water-absorbing plastic film. This has the extremely favorable result of preventing this.

In order to exhibit the characteristics of the composition of this invention most significantly,
It is desirable to form it into a film, and therefore it can be used not only as a food packaging material, a water retaining material for agriculture or horticulture, but also for water absorption and drying, water leakage prevention, interior decoration, coating or packaging of medical and electrical parts, etc. It is extremely effective.

Examples will be described below. Note that "parts" or "%" described in the examples represent "parts by weight" or "% by weight" unless otherwise noted.

[Example 1] 10 parts of maleic anhydride was dissolved in 10 parts of acetone,
13 parts of polyvinyl alcohol was added thereto, stirred and reacted, and then the carboxyl residues were neutralized with an aqueous solution containing 4 parts of caustic soda. 1,2-polybutadiene (manufactured by Japan Synthetic Rubber Co., Ltd.: JSRRB) was added to 100 g of polymer.
100 g of a solvent solution having a polymer content of 10% in which 820) was dissolved in Dorol was added and mixed thoroughly with stirring.

After removing the IVol from the mixture of the water-absorbing polymer and polymer solvent solution obtained in this manner by drying with hot air, 100 g of this mixture was mixed with 100 g of 1,2-polybutadiene.
In addition to 0 g, the mixture was sufficiently stirred and mixed using a Henschel mixer, and the mixture was kneaded at 150° C. using a vented extruder, extruded into strands, and cut into pellets. Using a film molding machine, the pellets were molded to a thickness of 50 μm.
A high-quality water-absorbing composite film with a water absorption rate of 5 liters was obtained.

[Example 2] Water-absorbing polymer white powder 100 obtained in the same manner as in Example 1
g, a mixture of 1 g of liquid paraffin and 1 g of di(dioctyl phosphate) ethylene titanate was added and mixed with stirring, and this was mixed with 1,2-polybutadiene (same as in Example 1).
1,000 g and extruded using a twin screw extruder at a resin temperature of 150°C, using a blown film die (diameter 75 mm, lip gap 9).
．． At a flow ratio of 4.8, a film with a thickness of 18 μm was obtained. This film has a water absorption rate of 10% and is of extremely high quality.

[Example 31 10 parts of maleic acid and 7 parts of acrylic acid were combined in 7-1
! ), 13 parts of polyvinyl alcohol was added thereto, stirred and reacted, and then neutralized with an aqueous solution containing 4 parts of caustic soda. 10 g of process oil (manufactured by Japan Synthetic Rubber Co., Ltd.: J S RAROMA) was added and mixed with stirring, and this was mixed with the same 1,2-polybutadiene 3 as in Example 1.
00g and formed into a film under the same conditions as Example 2. The obtained film was an extremely high quality water-absorbing composite film with a thickness of 18 μm and a water absorption rate of 20%.

[Example 4] 1'00 g of water-absorbing polymer powder obtained in the same manner as in Example 3
and 1 polymer component of polystyrene dissolved in ethyl acetate.
After adding 100 g of a solvent solution having 0% and stirring thoroughly, this was mixed for about 2 hours using a vacuum heating mixer.
! , 2-polybutadiene [manufactured by Japan Synthetic Rubber Co., Ltd.:
The mixture was mixed with 200 g of JSRRB 810) and made into pellets using a vent extruder and a granulator. This was formed into a film by the insillation method under the same conditions as in Example 2. The obtained film has a thickness of 18 μm and a water absorption rate of 5.
It was a good value of 0%.

[Brief explanation of drawings]

Figures 1 and 2 show that the matrix polymer is 1.2
FIG. 2 is a diagram showing the water absorption rate and the time course of the moisture absorption rate when polybutadiene or ethylene-vinyl acetate copolymer is used. Patent applicant Sangen Shokai Co., Ltd. Japan Synthetic Rubber Co., Ltd. Agent Kama 1) Text 2 Figure 1 Figure 2 Ichimasu review (4r) Procedural amendment (0 phantom Showa 57zu t'4111g1l 1988) Patent Application No. 39996 2, Name of the invention: Water-absorbing polybutadiene composition 3, Relationship with the amended case Patent applicant fl- Address: 3-17-8 Habigaoka, Habikino City, Osaka Prefecture
Name: Sangen Shokai Co., Ltd. (and 1 others)
name) 4, agent 5゜Showa year, month, day (Shipping 1]) 6
, the number of inventions to be increased by amendment Claims A finely powdered water-absorbing synthetic polymer mixed with at least one of the following: a plasticizer, a dispersant, or a solution in which a polymer component is dissolved; Furthermore, a water-absorbing polybutadiene composition characterized by being kneaded with 1.2-polybutadiene.

Claims (1)

[Claims] At least one part of the solution in which a plasticizer, a dispersant, or a polymer component is dissolved in a finely powdered water-absorbing synthetic polymer.
1. A water-absorbing polybutadiene composition, characterized in that a seed-mixed composition is further kneaded with 1,2-polybutadiene.