JP2017066362A - Organic polymer particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic polymer particle that has improved affinity with resin (particularly, polyolefin resin) and improved heat resistance, and reduced residual monomers.SOLUTION: An organic polymer particle comprises a copolymer having an alkyl (meth) acrylate monomer (A) unit with an alkyl group having one or more and 3 or less carbon atoms, an alkyl (meth) acrylate monomer (B) unit with an alkyl group having 4 or more carbon atoms, and a crosslinkable (meth) acrylic monomer (C) unit, and an antioxidant.SELECTED DRAWING: None

Description

  The present invention relates to organic polymer particles composed of a (meth) acrylic polymer crosslinked with a crosslinkable (meth) acrylic monomer.

  Resin films are widely used as various packaging materials. When the resin film is stored in a roll shape or in a stacked state, the films are blocked from each other, and may be difficult to slip or peel off. In order to prevent such blocking, an anti-blocking agent is used. In the present specification, the term “film” refers to a resin film unless otherwise specified.

  As the antiblocking agent, resin fine particles are widely used from the viewpoint of maintaining transparency of the film and suppressing scratches. As such resin fine particles, for example, Patent Document 1 describes (meth) acrylic crosslinked fine particles in which a residual crosslinking monomer is reduced by containing a surfactant and celluloses. Patent Document 2 describes polymer fine particles that contain a sulfur-based antioxidant and are excellent in heat resistance and color tone.

Japanese Patent Laying-Open No. 2015-67695 Japanese Patent No. 5572383

  However, conventional resin fine particles do not have sufficient affinity with resin (particularly polyolefin resin), and voids may occur when used in resin films. And as described in Patent Document 1, when various additives are used to suppress the generation of voids, the additive may bleed out, and on the other hand, an aromatic monomer to increase the affinity When the composition of the resin particle itself is adjusted by using the above, according to the study by the present inventors, the polymerization rate is not sufficient and a large amount of unreacted monomer may remain. Further, since the resin particles are molded at a high temperature during the production of the resin film, such resin particles are required to have heat resistance that reduces yellowing even at high temperatures. To improve heat resistance as described in Patent Document 2, When the antioxidant is added, the polymerization does not proceed sufficiently, and the problem of residual monomer may become more apparent.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide organic polymer particles with improved affinity and heat resistance with a resin (particularly, a polyolefin resin) and less residual monomer.

  The inventors of the present invention are diligently studying to solve the above-described problems, and by configuring the organic polymer particles with a monomer having a specific composition, polymerization is performed while increasing the affinity with a resin (particularly, a polyolefin resin). The efficiency can be increased, so that even when an antioxidant is used, the amount of residual monomer can be reduced, and even when heated to a high temperature, yellowing is suppressed, and organic polymer particles having good heat resistance are obtained. The present invention was completed by finding out that it can be obtained.

  That is, the organic polymer particle according to the present invention comprises an alkyl (meth) acrylate monomer (A) unit having an alkyl group having 1 to 3 carbon atoms and an alkyl (meta) having an alkyl group having 4 or more carbon atoms. ) A copolymer having an acrylate monomer (B) unit and a crosslinkable (meth) acrylic monomer (C) unit, and an antioxidant. The alkyl (meth) acrylate monomer (B) unit is 10 parts by mass or more in a total of 100 parts by mass of the alkyl (meth) acrylate monomer (A) unit and the alkyl (meth) acrylate monomer (B) unit. It is preferable that it is 70 mass parts or less.

The crosslinkable (meth) acrylic monomer (C) unit is preferably 3% by mass or more and 40% by mass or less in the copolymer constituting the organic polymer particles.
The crosslinkable (meth) acrylic monomer (C) is preferably a bifunctional crosslinkable (meth) acrylic monomer.

The thermal decomposition start temperature of the organic polymer particles is preferably 280 ° C. or higher.
Moreover, it is preferable that the density | concentration of the residual monomer amount in the said organic polymer particle is 1200 ppm (mass basis) or less.
The mass average particle diameter of the organic polymer particles is preferably 0.1 μm or more and 15 μm or less.

The organic polymer particles of the present invention are preferably used as an antiblocking agent for resin films. The resin film is preferably a polyolefin resin film.
A master batch containing the organic polymer particles and a resin is also included in the technical scope of the present invention.

  The organic polymer particle of the present invention contains a copolymer having a specific monomer unit and an antioxidant, and has improved affinity and heat resistance with a resin (particularly, a polyolefin resin), and a residual monomer amount. Is reduced.

1. Organic Polymer Particles The organic polymer particles of the present invention comprise an alkyl (meth) acrylate monomer (A) unit having an alkyl group having 1 to 3 carbon atoms, and an alkyl group having 4 or more alkyl carbon atoms ( It contains a copolymer having a (meth) acrylate monomer (B) unit, a crosslinkable (meth) acrylic monomer (C) unit, and an antioxidant. An alkyl (meth) acrylate monomer (B) unit in which the alkyl group has 4 or more carbon atoms, based on an alkyl (meth) acrylate monomer (A) unit in which the alkyl group has 1 to 3 carbon atoms Since the polymerization efficiency is enhanced while the affinity with a resin (particularly, polyolefin resin) is enhanced, the monomer remaining in the organic polymer particles can be reduced even when an antioxidant is used. .
In the present specification, the monomer unit means a structural unit derived from the monomer in the polymer.

  Examples of the alkyl (meth) acrylate monomer (A) having 1 to 3 carbon atoms in the alkyl group used in the organic polymer particles of the present invention include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) ) Acrylate, isopropyl (meth) acrylate and the like, and one or more can be used. From the viewpoint of easy formation of particles, methyl methacrylate is particularly preferable. The alkyl (meth) acrylate monomer (C3) is preferably alkyl methacrylate.

  The proportion of the alkyl (meth) acrylate monomer (A) unit in the copolymer constituting the organic polymer particles is preferably 20% by mass or more, more preferably 25% by mass or more, and further preferably 30% by mass. % Or more, particularly preferably 35% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, and further preferably 65% by mass or less.

  When the alkyl (meth) acrylate monomer (B) used in combination is an alkyl methacrylate monomer, the proportion of the alkyl (meth) acrylate monomer (A) unit is in the copolymer constituting the organic polymer particles. 30% by mass or more, more preferably 40% by mass or more, preferably 65% by mass or less, and more preferably 60% by mass or less.

Further, when the alkyl (meth) acrylate monomer (B) used in combination is an alkyl acrylate monomer, the proportion of the alkyl (meth) acrylate monomer (A) unit is in the copolymer constituting the organic polymer particles. , 50% by mass or more, more preferably 60% by mass or more, preferably 75% by mass or less, and more preferably 70% by mass or less.
The proportion of each monomer in the total amount of raw material monomers can be approximated to the proportion of structural units derived from each monomer in the copolymer. In this specification, the numerical range described for the proportion of each monomer in the total amount of raw material monomers Can be applied to the proportion of structural units derived from each monomer in the copolymer.

The alkyl group of the alkyl (meth) acrylate monomer (B) having 4 or more carbon atoms in the alkyl group is a group represented by C _n H _{2n + 1} , which is a chain and a straight chain. Alternatively, it may be branched. Examples of such an alkyl group include n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n- Linear such as dodecyl group (lauryl group), n-tridecyl group, n-tetradecyl group (myristyl group), n-hexadecyl group (palmityl group), n-octadecyl group (stearyl group), docosyl group (behenyl) group, etc. Alkyl group; t-butyl group, isobutyl group, isopentyl group, t-pentyl group, neopentyl group, isohexyl group, isoheptyl group, isooctyl group, 2-ethylhexyl group, isononyl group, isodecyl group, isoundecyl group, isododecyl group, isotridecyl group And branched alkyl groups such as dodecylpentadecyl group;
Moreover, it is preferable that carbon number of the alkyl group of an alkyl (meth) acrylate type monomer (B) is 4 or more and 24 or less, More preferably, it is 18 or less, More preferably, it is 12 or less. From the viewpoint of heat resistance, the alkyl group preferably has 8 or less carbon atoms, more preferably 6 or less. From the viewpoint of reducing the residual monomer, the alkyl group preferably has 6 or more carbon atoms, more preferably 8 or more.
The (meth) acryloyl group of the alkyl (meth) acrylate monomer (B) is preferably a methacryloyl group.

  Specific examples of the alkyl (meth) acrylate monomer (B) include n-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, and hexyl (meth). Acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), tridecyl (meth) acrylate, isotridecyl (meth) acrylate, tetradecyl (meta) ) Acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, chain alkyl (meth) acrylate such as dodecylpentadecyl (meth) acrylate; It is.

  The alkyl (meth) acrylate monomer (B) may be used without any particular limitation on the glass transition temperature (Tg) of the homopolymer, but one having a lower Tg of the homopolymer is selected from the above. May be used. Tg may be, for example, 50 ° C. or lower, preferably 25 ° C. or lower, more preferably 0 ° C. or lower, and particularly preferably −10 ° C. or lower. If the low Tg monomer (B) is used, when organic polymer particles are blended in the film as an anti-blocking agent, the particles can be more effectively prevented from falling off the film.

  In the copolymer constituting the organic polymer particles, the alkyl (meth) acrylate monomer (B) unit is preferably 3% by mass or more, more preferably 10% by mass or more, and still more preferably 20%. It is preferably at least 25 mass%, more preferably at least 70 mass%, more preferably at most 65 mass%, further preferably at most 60 mass%, particularly preferably at most 55 mass%. is there. The more the alkyl (meth) acrylate monomer (B) unit, the easier it is to reduce the residual monomer.

In particular, when the alkyl (meth) acrylate monomer (B) unit is an alkyl methacrylate unit, the proportion thereof is preferably 25% by mass or more, more preferably in the copolymer constituting the organic polymer particles. It is 30% by mass or more, preferably 60% by mass or less, and more preferably 50% by mass or less.
When the alkyl (meth) acrylate monomer (B) unit is an alkyl acrylate unit, the proportion is preferably 5% by mass or more, more preferably 7% in the copolymer constituting the organic polymer particles. It is at least mass%, preferably at most 30 mass%, more preferably at most 20 mass%.

  The alkyl (meth) acrylate monomer (B) unit is 5 parts by mass or more in a total of 100 parts by mass of the alkyl (meth) acrylate monomer (A) unit and the alkyl (meth) acrylate monomer (B) unit. More preferably, it is 10 parts by mass or more, more preferably 20 parts by mass or more, preferably 80 parts by mass or less, more preferably 70 parts by mass or less, still more preferably 60 parts by mass or less, The amount is particularly preferably 50 parts by mass or less.

The copolymer constituting the organic polymer particles further contains a crosslinkable (meth) acrylic monomer (C) unit. Thereby, the alkyl (meth) acrylate monomer (A) unit having 1 to 3 carbon atoms in the alkyl group and the alkyl (meth) acrylate monomer (B) having 4 or more carbon atoms in the alkyl group are obtained. Crosslinking is performed by the crosslinkable (meth) acrylic monomer (C) unit, and the mechanical properties are easily adjusted. The crosslinkable (meth) acrylic monomer (C) is preferably a monomer having two or more (meth) acryloyl groups in one molecule, and the number of (meth) acryloyl groups is 2 to 6 Is preferable, more preferably 2 to 3, particularly preferably 2.
The (meth) acryloyl group is preferably a methacryloyl group.

  Further, two or more (meth) acryloyl groups are preferably bonded via a chain (preferably a straight chain) hydrocarbon chain in the crosslinkable (meth) acrylic monomer (C), More preferably, the (meth) acryloyl group is bonded to a diol compound such as alkylene glycol; a triol compound; a polyol compound such as a tetraol compound by forming an ester bond. As the polyol compound, alkylene glycols such as ethylene glycol, butanediol, hexanediol, and nonanediol are preferable, and ethylene glycol is particularly preferable.

  Among the crosslinkable (meth) acrylic monomers (C), specific examples of the bifunctional crosslinkable (meth) acrylic monomers include ethylene glycol di (meth) acrylate and 1,4-butanediol di (meth). Alkanediol di (meth) acrylate such as acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate; Alkendi (meth) such as 1,3-butylene di (meth) acrylate Acrylate; polyethylene glycol di (meth) acrylate (the number of repeating ethylene glycol units is, for example, 2 to 150); and the like. The trifunctional crosslinkable (meth) acrylic monomer includes trimethylolpropane tri (meth) acrylate, and the tetrafunctional crosslinkable (meth) acrylic monomer includes pentaerythritol tetra (meth) acrylate. Examples of the hexafunctional crosslinkable (meth) acrylic monomer include dipentaerythritol hexa (meth) acrylate. These monomers can use 1 type (s) or 2 or more types.

  Among them, the crosslinkable (meth) acrylic monomer (C) is preferably a 2-6 functional crosslinkable (meth) acrylic monomer, more preferably a 2-4 functional crosslinkable (meth) acrylic monomer, Bifunctional crosslinkable (meth) acrylic monomers are preferred, and alkanediol di (meth) acrylate is particularly preferred.

  The ratio of the crosslinkable (meth) acrylic monomer (C) unit is preferably 3% by mass or more, more preferably 5% by mass or more in the copolymer constituting the organic polymer particles. The content is preferably at most mass%, more preferably at most 30 mass%, further preferably at most 20 mass%, particularly preferably at most 15 mass%.

  Alkyl (meth) acrylate monomer (A) unit having 1 to 3 carbon atoms in the alkyl group, alkyl (meth) acrylate monomer (B) unit having 4 or more carbon atoms in the alkyl group, and crosslinkability (meth) ) The total of acrylic monomer (C) units is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 98% by mass or more in the copolymer constituting the organic polymer particles. is there.

  The copolymer constituting the organic polymer particles includes an alkyl (meth) acrylate monomer (A) in which the alkyl group has 1 to 3 carbon atoms, and an alkyl (meth) acrylate in which the alkyl group has 4 or more carbon atoms. A structural unit derived from a monomer (D) other than the monomer (B) and the crosslinkable (meth) acrylic monomer (C) may be included. As other monomer (D), cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, cyclooctyl (meth) acrylate, isobornyl (meth) acrylate, 4-t-butylcyclohexyl (meth) Cyclic alkyl (meth) acrylates such as acrylates; Olefin monomers such as ethylene, propylene and butylene; Vinyl halide monomers such as vinyl chloride; Vinyl ester monomers such as vinyl acetate; Nitrile monomers such as acrylonitrile; (Meth) acrylamide monomers such as (meth) acrylamide; N-vinylpyrrolidone; monocyclic ether-containing acrylates such as tetrahydrofurfuryl (meth) acrylate; styrene, α-methylstyrene , O-methylstyrene, m-methylstyrene, p-methylstyrene, ethylvinylbenzene, p-tert-butylstyrene, p-methoxystyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p- Styrenic monomers such as chlorostyrene; aromatic divinyl compounds such as m-divinylbenzene, p-divinylbenzene, divinylnaphthalene, and derivatives thereof; N, N-divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfonic acid, etc. Cross-linking agent; polybutadiene; JP-B-57-56507, JP-A-59-221304, JP-A-59-221305, JP-A-59-221306, JP-A-59-221307, etc. A reactive polymer to be described; and the like.

The proportion of other monomer (D) units is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 2% by mass or less in the copolymer forming the organic polymer particles. It is especially preferable that it is 0 mass%.
Among them, the ratio of vinyl group-containing aromatic monomer units such as styrene monomers and aromatic divinyl compounds is preferably 5% by mass or less, more preferably 2% in the copolymer forming the organic polymer particles. % By mass or less, more preferably 1% by mass or less, and particularly preferably 0% by mass.
Furthermore, the ratio of the cyclic alkyl (meth) acrylate unit is preferably 5% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less in the copolymer forming the organic polymer particles. It is especially preferable that it is 0 mass%.

  Alkyl (meth) acrylate monomer (A) unit having 1 to 3 carbon atoms in the alkyl group, alkyl (meth) acrylate monomer (B) unit having 4 or more carbon atoms in the alkyl group, crosslinkable (meth) acrylic The copolymer having the system monomer (C) unit and, if necessary, another monomer (D) unit is preferably 90% by mass or more, more preferably 95% by mass or more, in the organic polymer particles. More preferably, it is 98 mass% or more.

  Moreover, the organic polymer particle of the present invention contains an antioxidant. By containing the antioxidant, the heat resistance of the organic polymer particles is improved, and yellowing can be suppressed even when heated to a high temperature. When an antioxidant (especially, one having a radical scavenging action) is used, the progress of the polymerization reaction is hindered. However, in the present invention, since the organic polymer particle-forming monomer is copolymerized, the polymerization efficiency can be increased, and even when an antioxidant (particularly, one having a radical scavenging action) coexists. Residual monomer can be reduced.

  Antioxidants include those having radical scavenging activity such as hindered phenolic antioxidants and hindered amine antioxidants (radical scavengers); peroxides such as phosphorus antioxidants and sulfur antioxidants. Examples thereof include those having an action of decomposing (peroxide decomposing agents); other antioxidants such as lactone-based antioxidants, hydroxyamine-based antioxidants, vitamin E-based antioxidants, and the like. Among these, radical scavengers are preferable, and hindered phenol antioxidants are more preferable.

  The hindered phenol antioxidant has a structure in which a tert-butyl group is substituted at the ortho position of phenol. Specific examples of the hindered phenol-based antioxidant include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-dithione). -Tert-butyl-1-hydroxyphenyl) propionate, N, N'-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionamide], benzenepropane Acid, 3,5-bis (1,1-dimethylethyl) -4-hydroxy, C7-C9 side chain alkyl ester, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl- a, a ′, a ″-(mesitylene-2,4,6-tolyl) tri-p-cresol, calcium diethylbis [[[3,5-bis (1,1-dimethyl) Ruethyl) -4-hydroxyphenyl] methyl] phosphonate], ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3 5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2, 4,6 (1H, 3H, 5H) -trione, 1,3,5-tris [(4-tert-butyl-3-hydroxy-2,6-xylyl) methyl] -1,3,5-triazine-2 , 4,6 (1H, 3H, 5H) -trione, the reaction product of N-phenylbenzenamine and 2,4,4-trimethylbenzene, diethyl [[3,5-bis ( , 1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphonate, 2,4-dimethyl-6- (1-methylpentadecyl) phenol, octadecyl-3- (3,5-tert-butyl-4-hydroxyphenyl) ) Propionate, 2 ′, 3-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] propionohydrazide and the like.

  The hindered amine-based antioxidant has a structure in which two methyl groups are substituted for two methylene groups bonded to nitrogen atoms of secondary or tertiary amino groups. Specific examples of hindered amine antioxidants include 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, and 4-benzoyloxy. -2,2,6,6-tetramethylpiperidine, 3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidyl) pyrrolidine-2,5-dione, N-methyl-3-dodecyl -1- (2,2,6,6-tetramethyl-4-piperidyl) pyrrolidine-2,5-dione, N-acetyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4 -Piperidyl) pyrrolidine-2,5-dione, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4,5] decane-2,4-dione, Screw 2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1-octyloxy-2,2,6,6) -Tetramethyl-4-piperidinyl) sebacate, bis (1-undecanoxy-2,2,6,6-tetramethylpiperidin-4-yl) carbonate, bis (1,2,2,6,6-pentamethyl-4- Piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) butane-1 , 2,3,4-tetracarboxylate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) butane-1,2,3,4-tetracarboxylate Dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate and its condensate, poly [{6- (1,1,3,3-tetramethylbutyl ) Imino-1,3,5-triazine-2,4-diyne} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl) -4-piperidyl) imino}] and the like.

Examples of the phosphorus-based antioxidant include tris (2,4-di-tert-butylphenyl) phosphite, tris [2-[[2,4,8,10-tetra-tert-butyldibenzo [d, f]. [1,3,2] dioxaphosphine-6-yl] oxy] ethyl] amine, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis [2,4-bis ( 1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorous acid, tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite Etc .;

  Examples of the sulfur-based antioxidant include 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1,3,5-triazin-2-ylamino) phenol, 4,6 -Bis (octylthiomethyl) -o-cresol, 4,6-bis (dodecylthiomethyl) -o-cresol, diethyl-3,3'-thiodipropionate, dipropyl-3,3'-thiodipropionate , Dibutyl-3,3′-thiodipropionate, dihexyl-3,3′-thiodipropionate, dioctyl-3,3′-thiodipropionate, didodecyl-3,3′-thiodipropionate, ditridecyl 3,3-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, dioctadecyl-3,3′-thiodipropionate dimethyl , 3′-thiodipropionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis (3-methylthiopropionate), pentaerythritol tetrakis ( 3-ethylthiopropionate), pentaerythritol tetrakis (3-propylthiopropionate), pentaerythritol tetrakis (3-butylthiopropionate), pentaerythritol tetrakis (3-hexylthiopropionate), pentaerythritol Tetrakis (3-octylthiopropionate), pentaerythritol tetrakis (3-dodecylthiopropionate), pentaerythritol tetrakis (3-tridecylthiopropionate), pentaerythris Tall tetrakis (3-tetradecylthio propionate), pentaerythritol tetrakis (3-hexadecyl-thio propionate), pentaerythritol tetrakis (3-phenyl-thiopropionate); and the like.

  Examples of the lactone antioxidant include a reaction product of 3-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene (CAS No. 181314-48-7), and the like. Examples of hydroxyamine antioxidants include alkylamine oxidation products made from reduced beef tallow, and examples of vitamin E antioxidants include 3,4-dihydro-2,5,7,8-. And tetramethyl-2- (4,8,12-trimethyltridecyl) -2H-benzopyran-6-ol.

  The proportion of the antioxidant is preferably 0.001% by mass or more (10 ppm or more by mass) in the organic polymer particles, more preferably 0.003% by mass or more (30 ppm or more by mass), Preferably it is 0.005 mass% or more (50 ppm or more on a mass basis), preferably 1 mass% or less, more preferably 0.5 mass% or less, even if it is 0.1 mass% or less. Good. The organic polymer particles may contain a component derived from the antioxidant in addition to the antioxidant itself.

  Moreover, it is preferable that the component derived from a radical scavenger (especially hindered phenolic antioxidant) is 50 mass parts or more in 100 mass parts of all the components derived from antioxidant, More preferably, it is 80 masses. Part or more, more preferably 90 parts by weight or more, particularly preferably 95 parts by weight or more, most preferably 98 parts by weight or more, and the upper limit is 100 parts by weight.

  The organic polymer particles may contain other additives such as polysaccharides, anti-settling agents, fungicides, preservatives, ultraviolet absorbers, and light stabilizers. The total of other additives is preferably 10% by mass or less in the organic polymer particles, more preferably 5% by mass or less, still more preferably 2% by mass or less, and even more preferably 1% by mass or less. Preferably it is 0.5 mass% or less.

Since the organic polymer particle of the present invention contains the copolymer having the monomer unit, the residual amount of the monomer is suppressed.
Among them, the residual amount of the alkyl (meth) acrylate monomer (A) having an alkyl group having 1 to 3 carbon atoms is preferably 1000 ppm or less, more preferably 800 ppm, based on mass in the organic polymer particles. It is preferably 500 ppm or less, and more preferably 200 ppm or less. The residual amount of the alkyl (meth) acrylate monomer (A) in which the alkyl group in the organic polymer particles has 1 to 3 carbon atoms is most preferably 0 ppm on a mass basis, for example, 1 ppm or more, May be 3 ppm or more.

  The residual amount of the alkyl (meth) acrylate monomer (B) having 4 or more carbon atoms in the alkyl group is preferably 1000 ppm or less, more preferably 800 ppm or less, and 500 ppm or less on a mass basis. Preferably, it is more preferably 200 ppm or less. The residual amount of the alkyl (meth) acrylate monomer (B) in which the alkyl group in the organic polymer particles has 4 or more carbon atoms is most preferably 0 ppm on a mass basis, for example, 1 ppm or more, further 3 ppm. It may be the above.

  Further, the total amount of residual monomers is preferably 2500 ppm or less on a mass basis in the organic polymer particles, more preferably 1500 ppm or less, still more preferably 1200 ppm or less, particularly preferably 1000 ppm or less, and most preferably 500 ppm or less. It is. The total amount of residual monomers in the organic polymer particles is most preferably 0 ppm on a mass basis, but may be, for example, 10 ppm or more, and further 100 ppm or more. If the total remaining amount of monomers is within the above range, it can be used for food packaging films, pharmaceutical packaging films and the like.

  The organic polymer particles of the present invention include a copolymer having a specific copolymer composition, and since the polymerization rate is increased, the residual monomer amount is reduced, and high temperature (for example, 180 to 240 ° C., preferably 200 ° C.). Even when heated at ˜220 ° C., yellowing is suppressed.

  The water content of the organic polymer particles of the present invention is preferably 2% by mass or less, more preferably 1% by mass or less, still more preferably 0.5% by mass or less, particularly preferably in the organic polymer particles. It is 0.2 mass% or less. The moisture content can be adjusted by the drying time and drying temperature of the organic polymer particles, and the moisture content falls within the above range by drying at 80 to 90 ° C. (preferably 85 to 90 ° C.) for 10 hours or more (preferably 12 hours or more). The amount can be reduced.

The thermal decomposition start temperature of the organic polymer particles of the present invention is preferably 270 ° C. or higher, more preferably 280 ° C. or higher, more preferably 290 ° C. or higher, for example 350 ° C. or lower, May be 330 ° C. or lower.
The thermal decomposition start temperature is determined by using a thermal analyzer as the intersection of the extension line of the base line (horizontal line part) of the obtained TG (temperature-weight) curve and the tangent line of the mass reduction part (lower right oblique line part). Can be sought.

The mass average particle diameter of the organic polymer particles of the present invention is preferably 0.1 μm or more, more preferably 0.5 μm or more, further preferably 1 μm or more, particularly preferably 3 μm or more, and 20 μm or less. Is more preferably 15 μm or less, still more preferably 10 μm or less, still more preferably 7 μm or less, and particularly preferably 5 μm or less.
Further, the variation coefficient of the particle diameter of the organic polymer particles is preferably 50% or less, more preferably 45% or less, 5% or more, or 10% or more.
The variation coefficient of the particle diameter is obtained by the following formula. In the formula, σ represents the standard deviation of the mass-based particle diameter determined by a precision particle size distribution measuring apparatus using the Coulter counter method, and d50 represents the mass-based average particle diameter.
Coefficient of variation of particle diameter (%) = (σ / d50) × 100

  The organic polymer particles of the present invention have an improved affinity and heat resistance with a resin (particularly a polyolefin resin) and a small amount of residual monomer. For this reason, it is suitably used as an antiblocking agent, a lubricant and the like for various films. The particle diameter of the organic polymer particles of the present invention may be a spherical shape such as a true sphere, a porous shape, a protrusion, or an ellipse, and the particle surface may be modified so as not to impair the performance.

2. Production method The organic polymer particle of the present invention comprises an alkyl (meth) acrylate monomer (A) having 1 to 3 carbon atoms in the alkyl group, and an alkyl (meth) acrylate having 4 or more carbon atoms in the alkyl group. System-based monomer (B), crosslinkable (meth) acrylic monomer (C), and if necessary, other monomer (D) are subjected to suspension polymerization in the presence of a polymerization initiator and an antioxidant, followed by solid-liquid separation. And it can manufacture by collect | recovering a polymer.

Hereinafter, the method for producing organic polymer particles of the present invention will be described in each step.
In the suspension polymerization, first, the alkyl (meth) acrylate monomer (A) having 1 to 3 carbon atoms in the alkyl group, and the alkyl (meth) acrylate monomer having 4 or more carbon atoms in the alkyl group. (B), crosslinkable (meth) acrylic monomer (C), and, if necessary, other monomer (D) (hereinafter these monomers may be collectively referred to as “monomers for forming organic polymer particles”). ) Is dispersed and suspended in a solvent to obtain a monomer suspension. By polymerizing the monomers in the obtained monomer suspension in the presence of an antioxidant, a suspension of organic polymer particles can be obtained.

The polymerization initiator is preferably a radical polymerization initiator (particularly a thermal polymerization initiator). Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, cyclohexanone peroxide. , T-butyl hydroperoxide, diisopropylbenzene hydroperoxide and the like peroxide polymerization initiators; 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile) 2,2'-azobis (2,3-dimethylbutyronitrile), 2,2'-azobis- (2-methylbutyronitrile), 2,2'-azobis (2,3,3-trimethylbutyro Nitrile), 2,2'-azobis 2-isopropylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-4-methoxy-2,4-dimethylvaleronitrile), 2- (carbamoylazo) isobutyro Examples thereof include azo compound-based polymerization initiators such as nitrile, 4,4′-azobis (4-cyanovaleric acid), dimethyl-2,2′-azobisisobutyrate.
Among these, a peroxide polymerization initiator is preferable.

  The 10-hour half-life temperature of the polymerization initiator is preferably in the range of 40 to 80 ° C. (preferably 50 to 70 ° C.) from the viewpoint of controlling the polymerization reaction and removing the polymerization initiator by increasing the temperature. .

  The polymerization initiator is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and still more preferably 1 part by mass or more with respect to 100 parts by mass of the total amount of monomers for forming organic polymer particles. It is preferable that it is 10 mass parts or less, More preferably, it is 5 mass parts or less, More preferably, it is 3 mass parts or less.

  And by making an antioxidant coexist in the case of a polymerization reaction, even if the obtained organic polymer particle is heated to high temperature, yellowing can be suppressed and heat resistance can be improved. And in this invention, since the said monomer for organic polymer particle formation is copolymerized, polymerization efficiency can be raised and antioxidant (especially radical scavenger, Preferably a hindered phenolic antioxidant) coexists. Also when it is made to do, a residual monomer can be reduced.

The antioxidant is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and 2 parts by mass or less with respect to 100 parts by mass of the total amount of monomers for forming the organic polymer particles. It is preferable that it is 1 part by mass or less.
Further, the radical scavenger (particularly hindered phenol-based antioxidant) is preferably 50 parts by mass or more, more preferably 80 parts by mass or more, and still more preferably 90 parts by mass in 100 parts by mass of the total amount of the antioxidant. Part or more, particularly preferably 95 parts by weight or more, most preferably 98 parts by weight or more, and the upper limit is 100 parts by weight.

  The organic polymer particles are usually prepared in an aqueous solvent in the presence of a dispersion stabilizer, and are prepared, for example, by suspension polymerization or emulsion polymerization (preferably suspension polymerization). According to these polymerization methods, the organic polymer particles can be formed into a spherical shape, and organic polymer particles having a uniform particle diameter can be obtained. For example, in the suspension polymerization method, a monomer suspension can be obtained by dispersing and suspending an organic polymer particle-forming monomer, a polymerization initiator, a surfactant, and an aqueous solvent. By polymerizing the monomers in the obtained monomer suspension, a suspension of organic polymer particles can be obtained.

  The dispersion stabilizer may be either an organic dispersion stabilizer or an inorganic dispersion stabilizer. Examples of the organic dispersion stabilizer include water-soluble polymers, anionic surfactants, cationic surfactants, nonionic surfactants, zwitterionic surfactants, alginate, zein, and casein. Examples of inorganic dispersion stabilizers include barium sulfate and calcium sulfate, barium carbonate, magnesium carbonate, calcium phosphate, talc, clay, diatomaceous earth, bentonite, titanium hydroxide, thorium hydroxide, metal oxide powder, and the like. May be used alone or in appropriate combination.

  Examples of the water-soluble polymer include water-soluble polymers such as polyvinyl alcohol, gelatin, tragacanth, starch, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, sodium polyacrylate, and sodium polymethacrylate.

Examples of the anionic surfactant include fatty acid salts such as sodium oleate and potassium castor oil; alkyl sulfate ester salts such as sodium lauryl sulfate and ammonium lauryl sulfate; alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate; alkyl Naphthalene sulfonate; alkane sulfonate; dialkyl sulfosuccinate; alkyl phosphate ester salt; naphthalene sulfonate formalin condensate; polyoxyalkylene alkyl ether sulfate such as polyoxyethylene alkyl ether sulfate; polyoxyethylene phenyl ether Polyoxyalkylene aryl ether sulfates such as sulfates; Polyoxyalkylene alkyl sulfates such as polyoxyethylene alkyl sulfates Le salts; and the like.
Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate; quaternary ammonium salts such as lauryltrimethylalkylammonium chloride.
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine, and glycerin fatty acid. Examples thereof include esters and oxyethylene-oxypropylene block copolymers.
Examples of amphoteric surfactants include lauryl dimethylamine oxide.
Among these, an anionic surfactant is preferable and polyoxyalkylene aryl ether sulfate is more preferable from the viewpoint of good polymerization stability and suspension stability.

  In this step, the dispersion stabilizer is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, with respect to 100 parts by mass of the total amount of monomers for forming the organic polymer particles. The amount is preferably at most 3 parts by mass, more preferably at most 3 parts by mass, even more preferably at most 2 parts by mass. The more surfactant, the better the suspension stability.

  The aqueous solvent may be water alone or a combination of water and a non-aqueous solvent. Water is, for example, 80 parts by mass or more, preferably 90 parts by mass or more, more preferably 95 parts by mass or more, and particularly preferably 99 parts by mass or more in 100 parts by mass of the aqueous solvent.

The non-aqueous solvent is preferably a water-soluble organic solvent. By using a non-aqueous solvent (particularly a water-soluble organic solvent), the particle diameter of the obtained particles can be controlled. Examples of the water-soluble organic solvent include alcohol solvents such as methanol, ethanol, propanol, butanol, 2-methylpropyl alcohol and 2-methyl-2-propanol; ketone solvents such as acetone and methyl ethyl ketone; ester solvents such as ethyl acetate. Ether solvents such as dioxane, diethyl ether and tetrahydrofuran;
When a non-aqueous solvent is used, the amount used is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, more preferably 100 parts by mass of the organic polymer particle-forming monomer. The amount is preferably 1 part by mass or more, preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 3 parts by mass or less. When the non-aqueous solvent is in this range, the suspension stability is good.

  The aqueous solvent is preferably 200 parts by mass or more, more preferably 300 parts by mass or more, further preferably 350 parts by mass or more, with respect to 100 parts by mass of the monomer for forming organic polymer particles. It is preferably at most 700 parts by mass, more preferably at most 700 parts by mass, even more preferably at most 500 parts by mass.

  The order of addition of the surfactant, monomer, polymerization initiator, antioxidant, and solvent is not particularly limited. For example, the solvent is first mixed with the dispersion stabilizer, and then the monomer, the polymerization initiator, and the antioxidant are mixed. It is preferable to do. Moreover, it is preferable to previously dissolve the polymerization initiator and the antioxidant in the monomer.

  When these organic polymer particle-forming monomers, polymerization initiators, antioxidants, dispersion stabilizers, and aqueous solvents are dispersed and suspended, an emulsifying and dispersing device can be used. Examples of the emulsifying and dispersing apparatus include Milder (manufactured by Ebara Corporation), T.E. K. High-speed shear turbine type dispersers such as homomixers (manufactured by Primix Co., Ltd.); high-pressure jet homogenizers such as piston type high-pressure homogenizers (manufactured by Gorin) and microfluidizers (manufactured by Microfluidics Co., Ltd.); ultrasonic homogenizers Ultrasonic emulsification disperser such as (Nippon Seiki Seisakusho Co., Ltd.); Medium stirring disperser such as Attritor (Mitsui Mining Co., Ltd.); Forced gap such as colloid mill (Nihon Seiki Seisakusho Co., Ltd.) A pass-through disperser or the like can be used. In addition, you may pre-stir with a normal paddle blade etc. before the said dispersion | distribution and suspension.

The stirring speed during the dispersion and suspension is preferably 3000 rpm or more, and more preferably 4000 rpm or more. The larger the stirring speed, the smaller the particle diameter of the obtained organic polymer particles. Moreover, it is preferable that stirring time is 10 to 60 minutes normally. The longer the stirring time, the smaller the particle size of the organic polymer particles, and the narrower the particle size distribution. In addition, when the stirring time is within the above range, an increase in the liquid temperature can be prevented and the polymerization reaction can be easily controlled.

  When polymerizing the monomer suspension after forced stirring, the polymerization temperature is preferably 40 to 100 ° C, more preferably 50 to 90 ° C. The polymerization temperature is preferably 2 to 4 ° C. higher than the 10-hour half-life temperature of the polymerization initiator used. When the polymerization temperature is within the above range, the decomposition of the polymerization initiator proceeds moderately, the residual amount of the polymerization initiator in the resulting organic polymer particles is reduced, and at the same time, the polymerization stability is good. Specifically, when the polymerization initiator used is lauryl peroxide, the 10-hour half-life temperature of lauryl peroxide is 62 ° C., so the polymerization temperature is preferably 64 to 66 ° C.

  The polymerization time is preferably 5 to 600 minutes, more preferably 10 to 300 minutes. When the polymerization time is within the above range, the degree of polymerization can be increased moderately and the mechanical properties of the particles can be improved. The polymerization atmosphere is preferably an inert atmosphere such as a nitrogen atmosphere or a rare gas atmosphere.

  The obtained suspension of organic polymer particles is cooled to 50 ° C. or lower, and solid-liquid separation is performed to recover the organic polymer particles. As a solid-liquid separation method, an optimum method can be selected from filtration, centrifugation, and combinations thereof.

The obtained organic polymer particles may be concentrated or solid-liquid separated if necessary, and the solvent may be removed (preliminarily dried). Examples of the method of concentration or solid-liquid separation include sedimentation concentration, filtration, centrifugation (decanter), wet sieving, liquid cyclone, etc., and centrifugation (decanter) is preferable. The drying temperature is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, preferably 90 ° C. or lower, more preferably 80 ° C. or lower. The drying time is preferably 10 hours or more and 20 hours or less, more preferably 12 hours or more and 18 hours or less. As the drying time is longer, the water content can be reduced, and as the drying time is shorter, the coloring of the particles can be suppressed.
Furthermore, you may crush the organic polymer particle after drying as needed. The pulverization is preferably performed at 10 to 40 ° C., and the pulverization pressure is preferably 0.1 to 0.5 MPa.

  When producing the organic polymer particles, additives such as an anti-settling agent, an antifungal agent, an antiseptic, an ultraviolet absorber, and a light stabilizer may be allowed to coexist as long as the polymerization reaction is not affected.

3. Masterbatch As described above, the organic polymer particles of the present invention are useful as an additive for resins because the amount of residual monomer is reduced and little yellowing even when heated. The organic polymer particles of the present invention and the resin A masterbatch containing is also included in the scope of the present invention. In addition, since the organic polymer particles of the present invention maintain the affinity with the resin, it is easy to adjust the blending amount of the organic polymer particles in the obtained resin composition (masterbatch) or resin film, and organic Segregation can be suppressed by making the dispersion state of the polymer particles more uniform.

  As the resin used for the masterbatch, a resin classified as a thermoplastic resin can be used. Examples of the thermoplastic resin include polyester resin; polyolefin resin; polyamide resin; polyurethane resin; (meth) acrylic resin; polycarbonate resin; Among these, polyolefin resin is preferable. Examples of the polyolefin resin include polyethylene, polypropylene, poly (4-methylpentene), and polypropylene is preferable. The polypropylene resin mainly includes a homopolymer made of only polypropylene, and a random polymer obtained by copolymerizing propylene (preferably 95% by mass or more) and a small amount (preferably 5% by mass or less) of ethylene. The term “polypropylene resin” used in the present invention refers to general polypropylene resins having improved physical properties by copolymerization with these two types or other propylene. Among them, a polypropylene resin in which the proportion of units derived from propylene is preferably 90% by mass or more, more preferably 95% by mass or more is preferable.

  The resin is preferably 50% by mass or more in the master batch, more preferably 70% by mass or more, further preferably 80% by mass or more, particularly preferably 85% by mass or more, and 99% by mass or less. Is preferable, and more preferably 95% by mass or less.

  The content of the organic polymer particles in the master batch is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and further preferably 5 parts by mass or more with respect to 100 parts by mass of the resin in the master batch. 100 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 20 parts by mass or less, and still more preferably 15 parts by mass or less.

The master batch of the present invention preferably further contains an antioxidant. As the antioxidant, hindered phenol antioxidants and phosphorus antioxidants are preferable. In particular, the total of the hindered phenol antioxidant and the phosphorus antioxidant is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, particularly preferably 98% in the antioxidant. It is at least mass%.
Moreover, 20-80 mass% in hindered phenolic antioxidant is preferable in antioxidant, More preferably, it is 30-70 mass%, More preferably, it is 40-60 mass%.
Further, the antioxidant is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and further preferably 0.8 parts by mass or more with respect to 100 parts by mass of the resin in the masterbatch. 7 parts by mass or less, more preferably 4 parts by mass or less, further preferably 2 parts by mass or less, and particularly preferably 1.5 parts by mass or less.

  The yellow index (ASTM E313) of the master batch is preferably 6.3 or less, more preferably 6.2 or less, and even more preferably 6.1 or less.

As a method for preparing a masterbatch, for example, a method in which polymer particles are added and mixed in a polymerization stage for synthesizing a resin; a method in which a polymer after polymerization is melt-mixed using an extruder, etc .; a resin is dissolved in a solvent And a method in which polymer particles are added and mixed in such a state. Among these, since it is easy to produce a resin composition in which organic polymer particles are dispersed and contained at a high concentration, a melt-mixing method is preferable. Under the present circumstances, 180-240 degreeC is preferable and, as for melting temperature, 200-220 degreeC is more preferable.
The prepared master batch is usually processed into a powder form or a pellet form.

4). Resin Film The organic polymer particles of the present invention are useful as an antiblocking agent for resin films. The resin used for the resin film (hereinafter also referred to as “matrix resin”) can be selected from the range exemplified as the resin used for the masterbatch. In addition, when manufacturing a resin film after processing into a masterbatch, the matrix resin may be the same as or different from the resin used in the masterbatch.

  When organic polymer particles are used as an anti-blocking agent, the organic polymer particles are preferably 0.005 parts by mass or more, more preferably 100 parts by mass in total of the organic polymer particles and the resin film. Is 0.01 parts by mass or more, more preferably 0.2 parts by mass or more, preferably 2 parts by mass or less, more preferably 1 part by mass or less, still more preferably 0.5 parts by mass or less.

When the organic polymer particles of the present invention are used as an anti-blocking agent, it is possible to suppress the dropping of particles from the fine particle-containing resin film during the formation of the fine particle-containing resin film. Dropping of particles from the fine particle-containing resin film can be evaluated by the following dropping rate.
Dropout rate (%) = number of drops / (number of particles + number of drops)
Here, the number of dropouts is obtained by counting the number of particle dropouts included in a region of 270 μm × 200 μm and averaging the number of particle dropouts in 25 regions in a scanning electron microscope image at a magnification of 500 times. Value. The number of particles is a value obtained by counting the number of protrusions derived from organic polymer particles contained in the same region as the region where the number of particle drop marks was measured, and similarly averaging the number of particles for 25 regions. And
The drop-off rate from the fine particle-containing resin film immediately after molding is preferably 3% or less, more preferably 2.5% or less, and further preferably 2.0% or less.

Furthermore, by using the organic polymer particles of the present invention, even after the fine particle-containing resin film is rubbed, dropping of the particles from the fine particle-containing resin film is suppressed. For example, the drop-off rate after the following friction test is preferably 20% or less, more preferably 15% or less, and still more preferably 12% or less.
[Friction test]
The fine particle-containing resin films are in contact with each other on a measurement table in which a fine particle-containing resin film is fixed to a weight having a bottom width of 63.5 mm, a bottom length of 63.5 mm, and a weight of 200 g, and the fine particle-containing resin film is fixed to the upper surface. Place a weight to which the fine particle-containing resin film is fixed. Thereafter, the weight is slid in the same direction at a speed of 150 mm / min. The area where the weight is slid 20 times is taken as the measurement area.
When there is a difference in the degree of crystal growth on both surfaces of the fine particle-containing resin film and the smoothness is different, a surface with less crystal growth (more smooth) is used for the friction test.

Furthermore, the static friction coefficient μ _s of the fine particle-containing resin film is preferably 0.5 or less, more preferably 0.3 or less, still more preferably 0.25 or less, for example 0.01 or more. Is preferred.
The dynamic friction coefficient μ _k of the fine particle-containing resin film is preferably 0.3 or less, more preferably 0.25 or less, still more preferably 0.20 or less, for example 0.01 or more. Is preferred.

  The thickness of the resin film is preferably 0.1 μm or more, more preferably 0.5 μm or more, still more preferably 0.7 μm or more, and preferably 1 mm or less, more preferably 500 μm or less, More preferably, it is 400 micrometers or less.

  When manufacturing a resin film using organic polymer particles as an anti-blocking agent, the organic polymer particles are mixed with the resin for the film so as to have the above ratio after being processed directly or into the masterbatch (preferably Can be melt-mixed to obtain a resin composition, and by molding the resin composition, a fine particle-containing resin film can be produced. When molding the resin composition, the resin composition is preferably melt-extruded, and further stretched. An unstretched film (cast film) can be obtained by melt extrusion, and a stretched film can be produced by stretching the unstretched film (cast film). The resin used at this time may be the same as or different from the resin used for the masterbatch. In particular, from the viewpoint of productivity and processability, it is preferably a polyolefin resin, more preferably a polypropylene resin, still more preferably a unit derived from propylene, preferably 90% by mass or more, more preferably 95% by mass or more. Polypropylene resin, particularly preferably a homopolymer consisting only of polypropylene. By using the master batch, a resin composition having good dispersibility of the organic polymer particles can be obtained.

  In particular, the master batch contains a high concentration of organic polymer particles, and further mixed with a resin and diluted to obtain a resin composition in which the organic polymer particles are more uniformly dispersed. Can do. When using a masterbatch, the resin used for dilution is preferably 2 parts by mass or more and 200 parts by mass or less, more preferably 3 parts by mass or more and 150 parts by mass or less, with respect to 1 part by mass of the masterbatch. More preferably, they are 5 to 100 mass parts.

  As a method of forming the resin composition by mixing the organic polymer particles and the resin, a melt extrusion molding method such as a T-die method is preferable. What is necessary is just to coextrude, when laminating | stacking a fine particle containing resin film and a base film, and manufacturing a laminated | multilayer film. Under the present circumstances, 180-240 degreeC is preferable and, as for melting temperature, 200-220 degreeC is more preferable.

  In the organic polymer particles of the present invention, the residual monomer amount is suppressed, and yellowing is also suppressed during heating. Therefore, it is useful as an antiblocking agent for resin films. Moreover, the resin film containing the organic polymer particles of the present invention is suitably used as a general packaging material, a food packaging material such as a food packaging film, or a pharmaceutical packaging material such as a pharmaceutical packaging film.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention. In the following, “part” means “part by mass” and “%” means “mass%” unless otherwise specified.

The measurement methods used in the examples are as follows.
[Measurement of particle size and coefficient of variation]
About 0.1 g of organic polymer particles are dispersed in 0.5 g of a surfactant (“Neoperex (registered trademark) G15”, sodium dodecylbenzenesulfonate, manufactured by Kao Corporation), and then the above dispersion viscosity. After adding 15 g of deionized water to the liquid, ultrasonic waves are applied to prepare an organic polymer particle dispersion in which the particles are dispersed, and a precision particle size distribution measuring device (“Coulter made by Beckman Coulter Co., Ltd.) is prepared. The particle size of 30,000 particles was measured using “Multisizer type III”, aperture 50 μm), and the average particle size based on mass and the coefficient of variation of the particle size were determined.
Coefficient of variation of particle diameter (%) = (σ / d50) × 100
Here, σ is the standard deviation of the particle size, and d50 is the mass-based average particle size.

[Measurement of thermal decomposition start temperature]
The thermal decomposition start temperature of the organic polymer particles was measured using a thermal analyzer (DTG-50M, manufactured by Shimadzu Corporation), a sample amount of 15 mg, a heating rate of 10 ° C./min (maximum temperature reached 500 ° C.), Measurement was performed in air at a flow rate of 20 ml / min. First, using a precision balance, weigh a 15 mg sample in a specified aluminum cup, place this aluminum cup in a predetermined position on the thermal analyzer, and adjust the air to flow at a specified flow rate (20 ml / min). After the apparatus was stabilized, temperature increase was started. The intersection of the extension line of the base line (horizontal line part) of the TG curve (temperature-weight) obtained at this time and the tangent line of the mass decreasing part (lower slanted line part) is the thermal decomposition start temperature of the organic polymer particles. did.

[Measurement of residual monomer]
The residual monomer in the organic polymer particles was measured using a gas chromatograph, and the column was DB-1 (manufactured by J & W Scientific) with a length of 30 m and a column diameter of 0.53 mm. The vaporization chamber temperature was 280 ° C., the detector temperature was 280 ° C., the column temperature program was maintained at 50 ° C. for 3 min, then the temperature was increased to 260 ° C. at 10 ° C./min, and after reaching 260 ° C., 260 ° C. was maintained for 15 min. Butylbenzene was used as an internal standard, a calibration curve was prepared for the monomers used, and the amount of residual monomer in the organic polymer particles was quantified.

[Content of antioxidant in organic polymer particles]
Preparation of sample solution 1 g of a weighed sample (organic polymer particles) was mixed with 10 mL of chloroform and subjected to ultrasonic treatment to extract dissolved components in the fine particles. 100 mL of methanol was added to the resulting solution to insolubilize the polymer component, followed by filtration, and the resulting solution was concentrated. Next, 2 mL of chloroform was added here for dilution, and further acetonitrile was added to make the total volume 10 mL. The obtained solution was filtered with a filter having a pore diameter of 0.45 μm to obtain a sample solution.

Preparation of Standard Solution 12 mg of the antioxidant used in the following Examples and Comparative Examples was weighed into a 25 mL volumetric flask, dissolved by adding 5 mL of chloroform, and diluted with acetonitrile to prepare a 25 mL solution (concentration 480 ppm). This solution was appropriately diluted with acetonitrile to obtain a standard solution. This standard solution was subjected to high performance liquid chromatography (“NANOSPACE SI-2” manufactured by Shiseido Co., Ltd.), column: “CAPCELL PAK C18 MG” manufactured by Shiseido Co., Ltd., film thickness of 5 μm, 1.5 mm ID × 150 mm, detector: photodiode array. ) To create a calibration curve.

Measurement of Antioxidant Content Sample solution prepared by the above procedure was subjected to high performance liquid chromatography (“NANOSPACE SI-2” manufactured by Shiseido Co., Ltd.), column: “CAPCELL PAK C18 MG” manufactured by Shiseido Co., Ltd., film thickness of 5 μm. , 1.5 mm ID × 150 mm, detector: photodiode array), and the amount of antioxidant contained in the organic polymer particles of the following examples and comparative examples was calculated from a calibration curve prepared in advance with a standard solution. The lower limit of detection was 5 ppm. Measurement conditions are as follows.

Measurement conditions Column thermostat: 40 ° C
Eluent: methanol / acetonitrile = 50/50
Flow rate: 100 μL / min
Sample injection volume: 10 μL
Detection wavelength: 280 nm

[Yellowness evaluation]
10 parts of the organic polymer particles obtained above were rotated in the same direction as 90 parts of polypropylene pellets (Novatech FY4 manufactured by Nippon Polypro Co., Ltd.), 0.5 parts of antioxidant irganox (registered trademark) 1010, and 0.5 parts of irgafos 168. Using a twin-screw kneading extruder ((HK-25D), manufactured by Parker Corporation), melt kneading was carried out at 212 ° C., followed by water cooling to obtain a strand. A polypropylene master batch containing 10% of organic polymer particles was prepared by cutting appropriately.

About 7 g of the polypropylene masterbatch obtained above is put into Unipack A-8 (low density polyethylene bag manufactured by Nippon Shokubai Co., Ltd., thickness 0.08 mm, dimensions 70 mm × 50 mm), and a spectral color difference meter SE-6000 (Nippon Denshoku) The color was measured in the reflection mode using Kogyo Co., Ltd. The Yellow Index (ASTM E313) value was taken as MB evaluation.
The smaller this value is, the closer it is to white.

[Measurement of coefficient of friction (COF)]
The friction coefficient was measured using the biaxially stretched film (BOPP) obtained in Examples 1 and 5-7. When a cast film is produced by winding a film formed from a T-die extruder (manufactured by Soken Co., Ltd.), the cooling speed is controlled on the side that touches the take-up roll and on the opposite side (referred to as the air surface). There was a difference, and the crystal growth was suppressed on the roll surface side because the cooling rate was faster. For this reason, the finished cast film was smooth on the roll surface side, and a large crystal growth was seen on the air surface side, which was rough. In measurement of the coefficient of friction (COF), the roll surface side was set as a measurement target.
Autograph AG-X manufactured by Shimadzu Corporation was used as a friction coefficient measuring device. As a jig for friction coefficient measurement, load cell capacity 50N, dedicated friction coefficient measurement stand (width 200 mm x length 355 mm), moving weight (size width 63.5 mm x length 63.5 mm x thickness 6.4 mm, mass) 200 g) was used.
An area of 12 cm × 12 cm and an area of 12 cm × 18 cm in the central part of the film were used for the measurement. That is, a 12 cm × 18 cm sample and a 12 cm × 12 cm sample were cut from the center of the film. Then, a 12 cm × 18 cm sample was fixed to the measurement table with the roll surface side serving as the frictional resistance measurement surface facing up, and the four corners of the sample were fastened with cellophane tape. In addition, a moving weight was wrapped around a 12 cm × 12 cm sample so that the roll surface side was on the outside, and fixed with cellophane tape.
A moving weight wrapped with a sample was connected to a crosshead, slid at a speed of 150 mm / min on a film affixed to a measurement table, measured for running resistance, and the following static friction coefficient and dynamic friction coefficient were determined.
Coefficient of static friction = Maximum tensile test force at the start of moving weight / (Moving weight mass x Gravity acceleration)
Coefficient of dynamic friction = Average tensile test force during traveling of moving weight / (Moving weight mass x Gravity acceleration)
The travel distance was 100 mm, and the distance for obtaining the dynamic friction coefficient was 30 mm to 90 mm from the travel start point. The coefficient of friction was measured 20 times continuously, and the average value of the coefficient of friction was determined from the first four measurements. The film after the running resistance was measured 20 times was used as a film sample after a friction test with the following count of the number of dropouts.

[Count of dropouts in SEM measurement]
The surface of the obtained film sample after the friction test and the film sample that has not been subjected to the friction test are observed using a SEM (scanning electron microscope) VK-8500 (manufactured by Keyence Corporation) at an acceleration voltage of 5 kV (secondary electrons). Image).
About each film sample, 25 area | regions of 270 micrometers x 200 micrometers were image | photographed by 500 times visual field. The number of particles (number of protrusions derived from organic polymer fine particles) and the number of dropouts (particle dropout marks) included in each photographed image were counted, and the number of dropouts was determined based on the following formula. In addition, the dropout rate before the friction test (during stretching) is obtained from the number of dropouts and the number of particles in the film sample not subjected to the friction test, and the dropout rate after the friction test is obtained from the number of dropouts and the number of particles in the film sample after the friction test. I want.
Dropout rate (%) = number of drops / (number of particles + number of drops)

<Example 1>
Preparation of Organic Polymer Particles Polyoxyethylene distyryl phenyl ether sulfate ammonium salt (trade name “Hytenol (registered trademark) NF-08”) in a flask equipped with a stirrer, inert gas introduction tube, reflux condenser and thermometer. And 523 parts of deionized water in which 3.6 parts of Daiichi Kogyo Seiyaku Co., Ltd. were dissolved. 162 parts of methyl methacrylate (MMA), 36 parts of ethylene glycol dimethacrylate (EGDMA), 162 parts of n-butyl methacrylate (nBMA), lauryl peroxide as monomers for forming organic polymer particles prepared beforehand (LPO) 3.6 parts (1% by mass with respect to the monomer mass) and 1.8 parts (0.5% by mass with respect to the monomer mass) of hindered phenol antioxidant irganox (registered trademark) 1010 were charged. K. A homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd.) was stirred at 5000 rpm for 10 minutes to obtain a uniform suspension.

Add 900 parts of deionized water to the suspension, then heat the reaction solution to 65 ° C while blowing nitrogen gas, keep the reaction vessel at 65 ° C, and the temperature rises above 75 ° C due to self-heating. The reaction was started when the temperature reached A, and stirring was continued at this temperature for 1.5 hours, and then the polymerization solution was further heated to 85 ° C. and stirred for 2 hours to complete the polymerization reaction. Thereafter, the reaction liquid (suspension) is cooled, filtered, and the polymerization product is collected by filtration. Obtained.
Since the obtained dried organic polymer particles were aggregated by drying, they were pulverized at a pulverization pressure of 0.3 MPa at room temperature using a super jet mill SJ-500 (manufactured by Nissin Engineering Co., Ltd.).

<Examples 2-8, Comparative Examples 1-4>
In Example 1, instead of 162 parts of methyl methacrylate (MMA), 36 parts of ethylene glycol dimethacrylate (EGDMA) and 162 parts of n-butyl methacrylate (nBMA) as the monomer for forming organic polymer particles, Table 1, Organic polymer particles were prepared by the method described in Example 1, except that the organic polymer particle-forming monomer shown in Table 2 was used.
In Table 1, 2EHMA represents 2-ethylhexyl methacrylate, DMA represents dodecyl methacrylate, CHMA represents cyclohexyl methacrylate, AEH represents 2-ethylhexyl acrylate, and BA represents butyl acrylate.

  As shown in Tables 1 and 2, it can be seen that in the organic polymer particles having a predetermined monomer unit, the residual monomer is reduced, and yellowing when masterbatching is also suppressed. In addition, by co-polymerizing a monomer that lowers the Tg (glass transition temperature) of the homopolymer of the third component (B), adhesion (adhesion) can be imparted to the surface of the resulting organic polymer particles. It can be seen that dropout of particles from the film is suppressed (see Examples 1, 5, 6, and 7).

In the organic polymer particles of the present invention, the residual monomer amount is suppressed, and yellowing is also suppressed during heating. Therefore, it is useful as an antiblocking agent for resin films. Moreover, the resin film containing the organic polymer particles of the present invention is suitably used as a general packaging material, a food packaging material such as a food packaging film, or a pharmaceutical packaging material such as a pharmaceutical packaging film.

Claims (10)

  Alkyl (meth) acrylate monomer (A) unit having 1 to 3 carbon atoms in the alkyl group, alkyl (meth) acrylate monomer (B) unit having 4 or more carbon atoms in the alkyl group, and crosslinkability Organic polymer particles comprising a copolymer having a (meth) acrylic monomer (C) unit and an antioxidant.   The alkyl (meth) acrylate monomer (B) unit is 10 parts by mass or more in a total of 100 parts by mass of the alkyl (meth) acrylate monomer (A) unit and the alkyl (meth) acrylate monomer (B) unit. The organic polymer particle according to claim 1, which is 70 parts by mass or less.   The organic polymer particle according to claim 1, wherein the crosslinkable (meth) acrylic monomer (C) unit is 3% by mass to 40% by mass in the copolymer constituting the organic polymer particle. .   The organic polymer particle according to any one of claims 1 to 3, which has a thermal decomposition starting temperature of 280 ° C or higher.   The organic polymer particles according to claim 1, wherein the crosslinkable (meth) acrylic monomer (C) is a bifunctional crosslinkable (meth) acrylic monomer.   The organic polymer particles according to claim 1, wherein the concentration of the residual monomer amount is 1200 ppm (mass basis) or less.   The organic polymer particle according to any one of claims 1 to 6, which has a mass average particle diameter of 0.1 µm or more and 15 µm or less.   The organic polymer particle according to any one of claims 1 to 7, which is used as an antiblocking agent for a resin film.   The organic polymer particles according to claim 8, wherein the resin film is a polyolefin resin film. The masterbatch containing the organic polymer particle in any one of Claims 1-9, and resin.