JP2010265470A - Resin molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin molded product having a high water absorption effect which contains a water absorbing thermoplastic resin. <P>SOLUTION: The resin molded product contains a water absorbing thermoplastic resin in which an amide group is introduced in acrylonitrile in a polymer containing the acrylonitrile, and the amide group is introduced in an amount of 0.1-80 mol% based on the polymer. In the polymer, at least one selected from among a sulfonic acid and/or a sulfonate, a carboxylic acid and/or a carboxylate, -OH and/or an -OH salt, carbamoyl and/or a carbamoyl salt, an amine salt, an ammonium salt, -PO(OH)<SB>2</SB>and/or a -PO(OH)<SB>2</SB>salt, -CH<SB>2</SB>PO(OH)<SB>2</SB>and/or a -CH<SB>2</SB>PO(OH)<SB>2</SB>salt, and -NO<SB>2</SB>is introduced. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin molded body containing a water-absorbing thermoplastic resin.

  High water-absorbing resin has properties such as water retention, suction / swelling, thickening, and gelling power as well as water absorption, so in addition to typical disposable diapers (sanitary materials), civil engineering, agriculture, It is used in various fields such as cosmetics, toiletries, food, paints and toys.

JP 58-65187 A

  By the way, as a general superabsorbent resin, acrylic acid-based polymers and vinyl alcohol-based polymers are typified. However, since these resins usually do not show thermoplasticity, they are rarely used as resin moldings. . At best, only a technique (for example, refer to Patent Document 1) in which the same polymer (fine particles) is mixed with a thermoplastic resin having a relatively high affinity and used as a toy has been proposed. Even in this case, since the highly water-absorbent resin is difficult to be uniformly mixed with the thermoplastic resin, it is difficult to produce a molded product having a fine shape, and it is difficult to increase the mixing ratio in the thermoplastic resin. A resin molded body having a large water absorption effect could not be obtained. This is one obstructive factor in further expanding the applications of the current superabsorbent resin.

  The present invention has been proposed in view of the above-described conventional situation, and an object thereof is to provide a resin molded body having a large water absorption effect.

  The molded resin of the present invention contains a thermoplastic resin having water absorption, and the thermoplastic resin is formed by introducing an amide group into acrylonitrile in a polymer containing acrylonitrile, and the amide group is 0 with respect to the polymer. .1 to 80 mol% is introduced.

  Since the amide group is introduced into acrylonitrile in the acrylonitrile-containing polymer, the resin molded body of the present invention as described above has both water absorption and thermoplastic properties.

  In the present invention, a thermoplastic resin molded article having excellent water absorption can be realized. Thereby, the use of a water absorbing resin can be expanded greatly.

  Moreover, since the resin molding of this invention can utilize the used polymer which is difficult to recycle as a raw material, it leads to effective use of resources and can contribute to environmental preservation of the earth.

  Embodiments of the present invention will be described below.

  The resin molded body of the present invention comprises a thermoplastic resin having water absorption, and the thermoplastic resin has a predetermined polar group in a polymer containing at least one of acrylonitrile, styrene or conjugated diene as a constituent unit. It has been introduced. These constituent units of acrylonitrile, styrene, or conjugated diene impart thermoplasticity to the resin molding.

  The polymer constituting the thermoplastic resin is not particularly limited in the constituent ratios of various units in the polymer, but is preferably contained in the range of 0 to 95 mol%. In addition, it is more preferable that 10-60 mol% is contained as the acrylonitrile unit, and 20-85 mol% is contained as the styrene and / or conjugated diene (butadiene, isoprene, pentadiene, cyclopentadiene) unit. As described above, these units are necessary for the resin molding to have thermoplasticity.

  In addition to the acrylonitrile, styrene or conjugated diene, another constituent monomer may be contained in the polymer.

  As constituent monomers other than acrylonitrile, styrene or conjugated diene, aromatic monomers such as α-methylstyrene, vinyltoluene, vinylnaphthalene, olefins such as ethylene, propylene, butene, isobutylene, acrylic acid, methacrylic acid, maleic acid, Fumaric acid, crotonic acid, itaconic acid, citraconic acid, or esters thereof, acrylamide, methacrylamide, acrylic acid or acrylic acid ester (saturated or unsaturated hydrocarbons having 1 to 10 carbon atoms), methacrylic acid or methacrylic acid Examples thereof include monomers such as acid esters (saturated or unsaturated hydrocarbons having 1 to 10 carbon atoms), vinyl acetate, vinyl chloride, vinyl pyrrolidone, vinyl pyridine, and vinyl imidazole. These constituent monomers can be used alone or in combination of two or more. In addition, when these constituent monomers are used in combination, their content is suitably 50 mol% or less, preferably 2 to 40 mol%.

  Furthermore, in the resin molding of the present invention, polar groups as shown below are introduced into the polymer as described above. These polar groups give water absorption to the resin molding.

Examples of the polar group include sulfonic acid and / or sulfonate, amide, carboxylic acid and / or carboxylate, —OH and / or —OH salt, carbamoyl and / or carbamoyl salt, amine salt, ammonium salt, —PO There may be mentioned at least one of (OH) ₂ and / or —PO (OH) ₂ salt, —CH ₂ PO (OH) ₂ and / or —CH ₂ PO (OH) ₂ salt, —NO ₂ .

  As a method for introducing these polar groups into the aforementioned polymer, (1) a method in which at least one of acrylonitrile, styrene, and conjugated diene is directly introduced into a polymer containing constituent units (polymer reaction) And (2) a method of copolymerizing a monomer having a unit necessary for exhibiting thermoplasticity and a monomer having a polar group.

  First, the method (1) will be described. In this case, the polar group can be introduced by reacting a polymer containing at least one constituent unit of acrylonitrile, styrene, and conjugated diene with various agents.

  For example, as a polymer containing at least one of acrylonitrile, styrene, and conjugated diene, ABS (acrylonitrile-butadiene-styrene) resin, SAN (styrene-acrylonitrile) resin, HIPS (styrene-butadiene) resin, NBR (acrylonitrile- Examples thereof include polymers such as butadiene rubber resin, ASA resin (acrylonitrile-styrene-acrylate resin), ACS resin (acrylonitrile-chlorinated polyethylene-styrene resin), AAS resin (acrylonitrile-acrylic-styrene resin).

  These polymers may be newly manufactured virgin materials, discharged products (half-finished products) in the production process of resin raw materials and molded products, casings used in electrical products and automobiles, and various types It may be a used waste material molded for a specific purpose from a component material, a tube, a hose, or various buffer materials. The place of discharge may be from a factory, retail store, home, etc., but those collected from the factory, retail store, etc. have a relatively better composition than general waste from the home, etc. It is more desirable because there are many things.

  The molecular weight (Mw) of the polymer is not particularly limited, but the weight average molecular weight (Mw) is preferably 1,000 to 20,000,000, and more preferably 10,000 to 1,000,000. It is preferable that If the molecular weight is lower than this, it becomes liquid and does not form a resin, and if the molecular weight is higher than this, the melt viscosity becomes high, so that molding by heat melting becomes difficult.

  The polymer may be an alloy with another resin, or may be a waste material containing additives such as a face dye, a stabilizer, a flame retardant, a plasticizer, a filler, and other auxiliary agents. . Alternatively, it may be a mixture of used waste material and virgin material.

  Examples of other resins that can be mixed with the polymer include polyphenylene ether, polycarbonate, polyphenylene sulfide, polyethylene terephthalate, polybutylene terephthalate, polyamide, and polyester. In addition, it is desirable that these resins are mixed to 60% by weight or less with respect to the polymer. When the content of these resins increases, the reaction at the time of introducing the polar group is inhibited.

  A predetermined polar group can be introduced by performing the following reaction on the polymer shown above.

  For example, by reacting the polymer with a sulfonating agent (sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid, etc.) directly or in an organic solvent, an aromatic moiety (styrene, etc.) or a conjugated diene moiety (butadiene, etc.) Sulfonic acid groups can be introduced. Alternatively, the neutralized salt can be introduced as a polar group by reaction of this with a basic compound.

  Also, by reacting the polymer with a heated concentrated acid (such as sulfuric acid) or concentrated alkali (such as sodium hydroxide), the nitrile group in the polymer is converted into an amide group or a carboxyl group, or The saturated portion can be converted into a hydroxyl group and introduced into the polymer. Alternatively, the neutralized salt can be introduced as a polar group by reaction of this with a basic compound.

Moreover, by reacting and the polymer, and a mixture of concentrated sulfuric acid and nitric acid, can be introduced to the group -NO ₂ aromatic portion of the polymer (styrene).

In addition, n-butyllithium is added to the polymer, and then reacted with dry ice (CO ₂ ), whereby the carboxyl group is further hydrolyzed after the addition of phosphorus trichloride to —PO (OH) _2. Groups can be introduced into the polymer. Alternatively, the neutralized salt can be introduced as a polar group by reaction of this with a basic compound.

In addition, after chloromethylation of the styrene moiety in the polymer by Friedel-Craft reaction with chloromethyl ether and Lewis acid, ammonium salt and amine salt are converted into ionic groups by reacting with ammonia and various amine compounds. Can be introduced. Or, by hydrolysis after reaction with the chloromethyl compound and phosphorus trichloride, it can be introduced -CH ₂ PO _(OH) 2 and / or a salt thereof to the polymer.

  In addition, an imidazolinoalkyl structure is introduced by adding an alkylamine such as ethanolamine to the nitrile group in the polymer, or an imidazoline structure or an imidazolinoalkylamine structure is added by adding a polyamine such as ethylenediamine. Can be introduced. Alternatively, the neutralized salt can be introduced as a polar group by reaction of this with an acidic compound.

  Examples of basic compounds for neutralizing the acidic group include oxides, hydroxides, carbonates, acetates of alkali metals (sodium, lithium, potassium, etc.) and alkaline earth metals (magnesium, calcium, etc.), Compounds such as sulfates and phosphates, ammonia and various (first to third alkyl) amine compounds can be used.

  As the acidic compound for neutralizing the basic group, inorganic acids (sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, hydrofluoric acid, formic acid), organic acids (acetic acid, butyric acid, lactic acid, carboxylic acid), and the like can be used. .

  Next, the method (2) will be described. In this case, a desired polymer can be obtained by copolymerizing at least one monomer of acrylonitrile, styrene, or conjugated diene and at least one monomer having the following polar group.

  Examples of the monomer having a polar group include acrylamide, methacrylamide, acrylic acid and / or acrylate, methacrylic acid and / or methacrylate, vinyl sulfonic acid and / or vinyl sulfonate, allyl sulfonic acid and / or Or allyl sulfonate, methallyl sulfonic acid and / or methallyl sulfonate, 2-acrylamido-2-phenylpropane sulfonic acid and / or 2-acrylamido-2-phenylpropane sulfonate, 2-acrylamide-2- Vinyl monomers such as methylpropane sulfonic acid and / or 2-acrylamido-2-methylpropane sulfonate, vinyl phosphate, aminoalkyl (meth) acrylate and / or aminoalkyl (meth) acrylate salt, styrene sulfonic acid and / or Or sti Nsuruhon salts, ammonium salts of chloromethylstyrene, alkylamine salts and phosphoric acid esters and / or styrene monomers such as phosphoric acid ester salt, and imidazole and / or imidazole salts.

  Basic compounds for neutralizing the above acidic monomers include oxides, hydroxides, carbonates, acetates of alkali metals (sodium, lithium, potassium, etc.) and alkaline earth metals (magnesium, calcium, etc.) Further, compounds such as sulfates and phosphates, ammonia and various (1 to 3 alkyl) amine compounds can be used.

  Moreover, as an acidic compound for neutralizing a basic monomer, it is possible to use inorganic acids (sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, hydrofluoric acid, formic acid), organic acids (acetic acid, butyric acid, lactic acid, carboxylic acid), and the like. it can.

  By obtaining the above-mentioned monomer having a polar group and at least one monomer of acrylonitrile, styrene, or conjugated diene as described above or by polymerizing them in water or a solvent, a desired resin molding can be obtained. Can do.

  The molecular weight (Mw) of the copolymer is not particularly limited, but the weight average molecular weight (Mw) is preferably 1,000 to 20,000,000, and more preferably 10,000 to 1,000. , 000 is preferable. If the molecular weight is lower than this, it becomes liquid and does not have a shape as a resin. If the molecular weight is higher than this, the melt viscosity becomes high, so that molding by heat melting becomes difficult.

  In both cases of the methods (1) and (2) shown above, the polar group in the polymer is 0.1 to 80 mol%, preferably 1 to 70 mol%, based on all units. More preferably, it is contained in a proportion of 5 to 55 mol%. If the amount of polar groups introduced is too small, the water absorption effect of the polymer will be low, and if the amount of polar groups introduced is too large, the polymer will not exhibit thermoplasticity.

  And the said polymer manufactured by both the method of said (1) or the method of (2) is good also as a resin molding by mixing with other resin. As resins that can be mixed, polystyrene, ABS (acrylonitrile-butadiene-styrene) resin, SAN (styrene-acrylonitrile) resin, ASA resin (acrylonitrile-styrene-acrylate resin), ACS resin (acrylonitrile-chlorinated polyethylene-styrene resin) AAS resin (acrylonitrile-acrylic-styrene resin), HIPS (styrene-butadiene) resin, NBR (acrylonitrile-butadiene rubber) resin, polyphenylene ether, polycarbonate, polyphenylene sulfide, polyethylene terephthalate, polybutylene terephthalate, polyamide such as nylon, polyester , PVC, polyacrylonitrile, polyethylene, polypropylene, polylactic acid and the like.

  The resin that can be mixed may be a newly manufactured virgin material, a resin raw material or a discharge product (half-finished product) in the production process of a molded product, a casing used for an electric product or an automobile, etc. Alternatively, it may be a used waste material molded for a specific purpose from various component materials or tubes, hoses, and various cushioning materials. The place of discharge may be from a factory, retail store, or household, but the composition collected from the factory or retail store, etc., is relatively better than general industrial waste from the home. It is more desirable because there are many things.

  The molecular weight (Mw) of the resin is not particularly limited, but the weight average molecular weight (Mw) is preferably 1,000 to 20,000,000, and more preferably 10,000 to 1,000,000. It is preferable that If the molecular weight is lower than this, it becomes liquid and does not form a resin, and if the molecular weight is higher than this, the melt viscosity becomes high, so that molding by heat melting becomes difficult.

  In addition, the resin may be an alloy with another resin, or may be a waste material containing additives such as facial dyes, stabilizers, flame retardants, plasticizers, fillers, and other auxiliary agents. . Alternatively, it may be a mixture of used waste material and virgin material.

  The mixing ratio of these resins to the polymer having the polar group is not particularly affected by pharmaceuticals, but is preferably 99% by weight or less. If the content of these resins is increased, the water absorption of the resulting resin molded product is lowered.

  Since the resin molded body of the present invention as described above has a predetermined polar group introduced into a polymer containing at least one of acrylonitrile, styrene, and conjugated diene as a constituent unit, acrylonitrile, styrene, and conjugated diene. This unit will increase the thermoplasticity and the unit having a polar group will increase the water absorption.

  And the resin molded body of the present invention is a sanitary material, civil engineering, agriculture and forestry, horticultural material, a fragrance for a long-lasting fragrance, a dehydrating agent from an organic substance, a fire extinguishing agent, a sealing agent, a packing agent, Various anti-condensation agents, anti-static agents, coating agents, desiccants, water treatment agents, various structural molding materials (as parts materials for home appliances and automobiles), water-absorbing fibers, shape memory materials, sensor materials, etc. Can be used for applications.

  Hereinafter, the present invention will be specifically described by way of examples. Needless to say, the present invention is not limited to these examples.

<Example 1>
Freeze pulverization of ABS resin pellets (containing 45 mol% of styrene, 25 mol% of acrylonitrile, and 30 mol% of butadiene as constituent units) was made into a 16-32 mesh pulverized product. Next, 1 g of the pulverized product was added to 30 g of concentrated sulfuric acid (97% by weight) and reacted at 50 ° C. for 5 minutes. After completion of the reaction, the solid matter in the system was filtered through a glass filter, washed with water, and dried at 115 ° C. for 2 hours in a circulating air dryer. The content of sulfonic acid group and amide group in the obtained solid is 10 mol% (calculated from elemental analysis of sulfur) and 12 mol% (calculated from FT-NMR measurement results) with respect to all monomer units, respectively. Met.

  Next, the obtained solid was heat-pressed at 280 ° C. for 10 minutes to obtain a sheet-like water-absorbent resin molded body. The water absorption ratio (after 30 minutes) of the water-absorbent resin molded body was 80 times its own weight, and the shape after water absorption was substantially equal to the shape before water absorption.

<Example 2>
By mixing the raw material ABS resin pellets used in Example 1 and the ABS resin pellet reactant in a one-to-one ratio at a temperature of 280 ° C. for 10 minutes, a sheet-like water-absorbent resin molding is obtained. Could get. The water absorption ratio (after 30 minutes) of this water-absorbent resin molded body was 30 times its own weight, and the shape after water absorption was an approximately equal expansion of the shape before water absorption.

<Example 3>
A sheet-like water-absorbent resin molding was able to be obtained by heat-pressing a mixture of polycarbonate and the ABS resin pellet reactant of Example 1 in a ratio of 2 to 1 at 300 ° C. for 10 minutes. The water absorption ratio (after 30 minutes) of this water-absorbent resin molded body was 20 times its own weight, and the shape after water absorption was an approximately equal expansion of the shape before water absorption.

<Example 4>
Used 8mm cassette tape guard panel (transparent part) [SAN resin waste material: As a constituent unit, 60 mol% of styrene part and 40 mol% of acrylonitrile part are contained] It was a thing. Next, 1 g of this pulverized product was added to 30 g of used spent sulfuric acid (80% by weight) from a semiconductor factory and reacted at 80 ° C. for 5 minutes. After completion of the reaction, treatment was performed in the same manner as in Example 1 to obtain a sheet-like water-absorbent resin molded body. The sulfonic acid group and amide group contents in the resin were 38 mol% and 29 mol%, respectively, based on the total monomer units.

  Next, this material is cut into a star shape with scissors and immersed in pure water for 30 minutes to absorb 180 times its own weight of pure water, and the star shape is maintained. It remained.

  Furthermore, the water-absorbed product of the star-shaped water-absorbing resin molding was naturally dried at room temperature for 3 days, whereby a water-absorbing resin molding almost identical to the shape before water absorption could be obtained again. Based on the result, it can be considered as a shape memory resin.

<Example 5>
1 g of used acrylic fiber [PAN resin waste material: containing 95 mol% of acrylonitrile part and 5 mol% of vinyl acetate part as a constituent unit] with scissors was cut out with sodium hydroxide (5 wt%). In addition to 30 g, the mixture was reacted at 100 ° C. for 15 minutes. After completion of the reaction, the solid matter in the system was filtered with a glass filter, washed with water, and then dried at 115 ° C. for 2 hours with a circulating dryer. The total content of carboxylic acid groups and amide groups in the obtained solid was 8 mol% (calculated from FT-NMR measurement results) with respect to all monomer units.

  Next, a water-absorbing fiber could be obtained by spinning the obtained solid. The water absorption ratio of the water absorbent fiber to pure water (after 30 minutes) was 50 times its own weight, and the fiber was deformed thick due to water absorption.

<Example 6>
The blades of a used electric fan [SAN resin waste material: containing 40 mol% of styrene part and 60 mol% of acrylonitrile part as constituent units] were pulverized to obtain a 16 to 32 mesh pulverized product. Next, 1 g of the pulverized product was added to 30 g of ethylenediamine and reacted at 60 ° C. for 2 hours. After completion of the reaction, unreacted ethylenediamine was removed by distillation, and the residue was poured into acetone to reprecipitate the polymer. Next, the re-precipitate was filtered through a glass filter, washed with water, and dried at 115 ° C. for 2 hours in a circulating drier. The content of the imidazoline group in the obtained solid was 33 mol% (calculated from the measurement of FT-NMR) with respect to the total monomer units.

  Next, the obtained solid was heat-pressed at 280 ° C. for 10 minutes to obtain a sheet-like water-absorbent resin molded body. The water absorption ratio (after 30 minutes) of this water-absorbent resin molded body was 30 times its own weight, and the shape after water absorption was an approximately equal expansion of the shape before water absorption.

<Example 7>
A solution obtained by dissolving 5 g of polystyrene in 20 g of tetrachloroethane was added to 45 g of chloromethyl ether, and then 15 g of aluminum chloride was gradually added, followed by stirring at 60 ° C. for 1 hour (chloromethylation). After completion of the reaction, unreacted chloromethyl ether was distilled under reduced pressure, and then 15 g of trimethylamine was added to carry out quaternary amine salification. Thereafter, the precipitated solid was filtered through a glass filter, washed with acetone, and then dried at 50 ° C. for 2 hours in a vacuum dryer. The content of the quaternary amine salt in the obtained solid was 28 mol% (calculated from the measurement of FT-NMR) with respect to all monomer units.

  Next, the obtained solid was heat-pressed at 250 ° C. for 10 minutes to obtain a sheet-like water-absorbent resin molded body. The water absorption ratio (after 30 minutes) of this water-absorbent resin molded body was 25 times its own weight, and the shape after water absorption was substantially equal to the shape before water absorption.

<Example 8>
A sheet-like water-absorbent resin molding was able to be obtained by heat pressing a mixture of polyphenylene ether and the polystyrene reaction product of Example 7 at a ratio of 1 to 2 at 280 ° C. for 10 minutes. The water absorption ratio (after 30 minutes) of this water-absorbent resin molded body was about 15 times its own weight, and the shape after water absorption was substantially equal to the shape before water absorption.

<Comparative example 1>
The reaction conditions of Example 1 were changed to 100 minutes at 100 ° C. for reaction. After completion of the reaction, the solid matter in the system was filtered through a glass filter, washed with water, and dried at 115 ° C. for 2 hours in a circulating air dryer. The contents of sulfonic acid groups and amide groups in the obtained solid were 68 mol% and 22 mol%, respectively, with respect to the total monomer units.

  Next, the obtained solid was subjected to heat pressing at 280 ° C. for 10 minutes, but because it did not show thermoplasticity, a sheet-like resin molded body could not be obtained.

<Comparative example 2>
A commercially available crosslinked polyacrylate-based water-absorbing resin (powder product) was heat-pressed at 280 ° C. for 10 minutes, but because it did not show thermoplasticity, a sheet-like resin molded product could not be obtained. It was.

<Comparative Example 3>
A commercially available graft-type polyacrylate-based water-absorbing resin (powder product) was heat-pressed at 300 ° C. for 10 minutes, but because it did not show thermoplasticity, a sheet-like resin molded body could not be obtained. .

  As described above, the resins of Comparative Examples 1 to 3 have water absorption properties but have no thermoplasticity, and thus could not be molded into a desired shape.

  On the other hand, in the polymer containing at least one of acrylonitrile, styrene or conjugated diene as a constituent unit, the resin moldings of Examples 1 to 8 made of a thermoplastic resin into which a predetermined polar group is introduced, It combines thermoplasticity and water absorption, can be molded into a desired shape, and has sufficient water absorption.

Claims (6)

Containing a thermoplastic resin having water absorption,
The thermoplastic resin is a molded resin product in which an amide group is introduced into the acrylonitrile in a polymer containing acrylonitrile, and the amide group is introduced in an amount of 0.1 to 80 mol% with respect to the polymer.   The resin molding according to claim 1, wherein the amide group is introduced in an amount of 12 to 29 mol% based on the polymer.   The resin molding according to claim 1 or 2, wherein a resin other than the thermoplastic resin is mixed.   The resin molding according to any one of claims 1 to 3, wherein the polymer is at least one of acrylonitrile-butadiene-styrene resin, styrene-acrylonitrile resin, styrene-butadiene resin, and acrylonitrile-butadiene rubber. The polymers include sulfonic acid and / or sulfonate, carboxylic acid and / or carboxylate, -OH and / or -OH salt, carbamoyl and / or carbamoyl salt, amine salt, ammonium salt, -PO (OH) ₂ and / or —PO (OH) ₂ salt, —CH ₂ PO (OH) ₂ and / or —CH ₂ PO (OH) ₂ salt, or at least one salt selected from —NO ₂ has been introduced. The resin molding of any one of Claim 1 thru | or 4.   The resin molded body according to any one of claims 1 to 5, wherein the polymer is made of a used resin.