JP2012188553A - Polymer particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polymer particles that can more highly prevent resin discoloration and residual bubbles, when used as an additive for the resin.SOLUTION: The polymer particles is characterized in that a constituent is a copolymer comprising at least (A) a monofunctional (meth)acrylate-based monomer, (B) a multifunctional (meth)acrylate-based monomer, and (C) a styrenic monomer, and a mass reduction-starting temperature in an non-oxidizing atmosphere is ≥285°C.

Description

  The present invention relates to polymer particles having excellent heat resistance, and particularly relates to polymer particles having a high mass decrease start temperature in a non-oxidizing atmosphere.

  Conventionally, (meth) acrylic polymer particles have been used as resin additives (anti-blocking agents, light diffusing agents, etc.), matting agents, toner additives, powder coatings, water-dispersed coatings, decorative plate additives. It has been applied to a wide range of applications such as artificial marble additives, cosmetic fillers, and chromatography column fillers. Among these uses, particularly when used as an additive for a resin, the polymer particles are desired to have excellent heat resistance. That is, when a resin additive such as an anti-blocking agent is blended in the resin, melt mixing at a high temperature is usually performed. At this time, if the polymer particles used as the additive for the resin undergo thermal decomposition near the temperature at the time of melt mixing, the resin is colored due to the influence of the decomposition product, or the decomposition gas remains in the resin as bubbles. Happens. Such coloring of the resin and bubbles in the resin cause the mechanical and optical properties of the resin to deteriorate. In order to suppress such coloring and bubbles, the polymer particles are desired to have excellent heat resistance.

  Accordingly, various polymer particles having improved heat resistance have been proposed. For example, a resin particle having a (meth) acrylic monomer as a main component and having a weight reduction ratio of 60% by weight or less due to decomposition of an organic component of a polymer when held in air at 270 ° C. for 40 minutes (Patent Document 1 (claimed) Item 1))): organic polymer fine particles characterized by containing 10 ppm or more (mass basis) of an antioxidant essentially containing a sulfur-based antioxidant and having a thermal decomposition starting temperature of 290 ° C. or more. Patent Document 2 (see claim 1)); thermal decomposition starting temperature is 310 ° C. or higher, has a specific particle size distribution, and tetramethylsuccinonitrile content is 100 ppm or lower in the polymer fine particles. Polymer fine particles (see Patent Document 3 (Claim 1)); and the like have been proposed.

Japanese Patent Laid-Open No. 10-7730 International Publication No. 2008/133147 JP 2010-95598 A

  Conventionally, it has been known that by containing an additive such as an antioxidant, the temperature at which the polymer particles start to thermally decompose in earnest is improved and the heat resistance is improved. However, even polymer particles having a thermal decomposition starting temperature exceeding 340 ° C. may be colored with resin or residual bubbles when melt-mixed with the resin at a temperature of about 290 ° C. When this cause was examined, it was found that thermal decomposition slightly started at a temperature lower than the thermal decomposition start temperature, and that this slight decomposition product caused problems such as coloring. That is, in order to prevent coloring and bubbles, it was found that the temperature at which slight decomposition begins to occur is more important than the temperature at which full-scale thermal decomposition occurs (thermal decomposition start temperature).

  Moreover, the heat resistance evaluated in conventional polymer particles is the heat resistance in an air atmosphere. However, when the polymer particles and the resin are actually melt-mixed, it is usually performed in a non-oxidizing atmosphere such as a nitrogen atmosphere, and thus control of heat resistance in the non-oxidizing atmosphere is more important.

This invention is made | formed in view of the said situation, and when it is used as an additive for resin, it aims at providing the polymer particle which can prevent resin coloring and a residual bubble highly. That is, the present invention provides polymer particles in which the thermal decomposition slightly occurring in the low temperature region is suppressed and the heat resistance is essentially improved compared to the above-described full-scale thermal decomposition start.
The present invention also provides an additive for a resin that gives a resin composition in which coloring and bubbles are suppressed when the polymer particles are contained as an additive for a resin, and a resin containing the additive for resin and a resin. It is also intended to provide.

  By controlling the mass reduction start temperature in the non-oxidizing atmosphere of the (meth) acrylic polymer particles used for the resin additive, etc., the present inventors can color the resin molded product actually produced, The inventors found that air bubbles can be prevented and completed the present invention.

  The polymer particles of the present invention that have been able to solve the above-mentioned problems are at least (A) a monofunctional (meth) acrylate monomer and (B) a polyfunctional (meth) acrylate monomer ( C) It is made of a copolymer containing a styrene-based monomer, and has a mass reduction starting temperature in a non-oxidizing atmosphere of 285 ° C. or higher. The content of the (C) styrene monomer is 100 parts by mass in total of the (A) monofunctional (meth) acrylate monomer and the (B) polyfunctional (meth) acrylate monomer. It is preferable that it is 2 mass parts-100 mass parts. The thermal decomposition starting temperature of the polymer particles in a non-oxidizing atmosphere is preferably 340 ° C. or higher.

  The present invention includes an additive for a polyester resin containing the polymer particles and an antiblocking agent for a polyester resin containing the polymer particles. Moreover, the masterbatch containing the said additive for polyester resins and a polyester resin is a suitable aspect of this invention.

  The polymer particles of the present invention have a high mass decrease start temperature in a non-oxidizing atmosphere. Therefore, when used as an additive for a resin, the polymer particles of the present invention can impart properties such as anti-blocking properties and light diffusibility without causing resin coloring or residual bubbles.

It is a figure explaining the analysis method of a TG curve.

  The polymer particles of the present invention are further configured with respect to polymer particles having at least (A) a monofunctional (meth) acrylate monomer and (B) a polyfunctional (meth) acrylate monomer as constituent components. By adding (C) a styrene-based monomer as a component, the mass reduction start temperature in a non-oxidizing atmosphere is increased to 285 ° C. or higher.

  When a resin additive such as an anti-blocking agent is blended in the resin, melt mixing is usually performed at around 280 ° C. The polymer particles of the present invention have a mass reduction start temperature of 285 ° C. or higher, and no decomposition product is produced by melt mixing at around 280 ° C. For this reason, when the polymer particles of the present invention are used as an additive for a resin, coloring and residual bubbles are suppressed. Therefore, if the polymer particles of the present invention are used, characteristics such as anti-blocking property and light diffusibility can be imparted without impairing the original mechanical properties and optical properties of the resin.

  In order to allow the polymer particles of the present invention to be suitably used for melt mixing at a higher temperature, the mass decrease starting temperature is preferably 290 ° C. or higher, more preferably 295 ° C. or higher. The upper limit of the mass decrease start temperature is not particularly limited, but is usually 340 ° C. in the case of polymer particles having the composition defined in the present invention. The mass decrease start temperature can be appropriately adjusted by changing the type and content of the monomer constituting the polymer particles.

The reason why the mass reduction start temperature is specified in the present invention is as follows.
That is, the thermal decomposition starting temperature evaluated in the prior art is the extension of the base line (horizontal line part) of the TG curve obtained by thermogravimetric (TG) measurement and the mass decreasing part (lower right oblique line part). This is the temperature at the intersection with the tangent. Since this evaluation method draws a tangent line to the part where the mass decrease is stable (the part where the slope of the oblique line is stable), if the slope of this part is the same, full-scale thermal decomposition starts. Even those that do not generate decomposition products (when a steep curve is drawn from the horizontal line and shifts to the hatched part), those that are gradually released prior to full-scale thermal decomposition (gradual from the horizontal line) The case of drawing a curve and moving to the shaded area) was also evaluated as the same thermal decomposition start temperature. Therefore, in the latter case, even if the polymer particles are evaluated to have a high thermal decomposition starting temperature by the conventional evaluation method, a decomposition product is actually generated from a temperature lower than the evaluation temperature. When such polymer particles are used as an additive for a resin, there is a problem that coloring and residual bubbles are generated even when melt-mixed at a temperature lower than the thermal decomposition start temperature.

  In this way, when used as an additive for resins, even a small amount of decomposition products will adversely affect the resin, so the temperature at which decomposition products start to form rather than the temperature at which full-scale thermal decomposition starts (mass reduction) (Starting temperature) is considered important. Therefore, even if the decomposition is slight, the mass of the polymer particles decreases if the decomposition starts, and therefore, in the present invention, the mass decrease start temperature of the polymer particles is defined.

  Moreover, in this invention, since the coloring is suppressed and the resin composition excellent in transparency and its processed molded object are obtained, the one where the thermal decomposition start temperature in a non-oxidizing atmosphere is also high is preferable. The polymer particles of the present invention preferably have a thermal decomposition starting temperature in a non-oxidizing atmosphere of 340 ° C. or higher, more preferably 350 ° C. or higher, still more preferably 355 ° C. or higher, particularly preferably 360 ° C. or higher. The resin composition has an optimum temperature range for resin processing depending on its blending composition and degree of polymerization, but a processed product of a resin composition using various resins including a polyester resin can be prepared at around 300 ° C. . Therefore, if the thermal decomposition start temperature of the polymer particles is 340 ° C. or higher, the thermal decomposition temperature of the polymer particles is sufficiently high with respect to the processing temperature. The resin composition can be prepared with a melt viscosity. Thereby, for example, a processed product having a good dispersion state of the polymer particles can be obtained without coloring or a decrease in transparency.

  The upper limit of the thermal decomposition start temperature is not particularly limited, but is 400 ° C. in the case of polymer particles having the composition defined in the present invention. The thermal decomposition start temperature is achieved by constituting polymer particles from the above-described components, but the (D) maleimide monomer described later is further used as a constituent of the polymer particles; (E) Polymerization is carried out in the presence of a compound having a thiol group and a carboxyl group; In addition, the measuring method of the mass reduction start temperature and thermal decomposition start temperature in a non-oxidizing atmosphere will be described later.

  The volume average particle diameter of the polymer particles of the present invention is preferably 0.1 μm or more, more preferably 0.5 μm or more, further preferably 1.0 μm or more, preferably 20 μm or less, more preferably 10 μm or less, Preferably it is 5 micrometers or less. When the volume average particle size is within the above range, when used as an unreblocking agent for the resin composition, the effect of improving the slipperiness of a molded product obtained from the resin composition is improved. When the volume average particle diameter exceeds 20 μm, the slipperiness of the molded product tends to be too high. The coefficient of variation (CV value) in the volume-based particle diameter of the polymer particles is preferably 50% or less, more preferably 40% or less, and even more preferably 35% or less.

  The polymer particles of the present invention comprise (meth) acrylic polymer particles containing at least (A) a monofunctional (meth) acrylate monomer and (B) a polyfunctional (meth) acrylate monomer as constituent components. It is. And in the polymer particle of this invention, in order to raise the mass reduction start temperature in non-oxidizing atmosphere, it is essential to mix | blend (C) styrene-type monomer as a structural component. Hereinafter, each component will be described. In the present application, (meth) acrylate indicates acrylate, methacrylate, and a mixture thereof, and (meth) acrylic acid indicates acrylic acid, methacrylic acid, and a mixture thereof.

(A) Monofunctional (meth) acrylate monomer The (A) monofunctional (meth) acrylate monomer has one (meth) acryloyl group in the molecule, and the (meth) acryloyl group In addition to the above, it is a monomer having no polymerizable group. Here, the “polymerizable group” may be any group that can form a bond with another monomer. For example, in addition to a radical polymerizable group such as a vinyl group, an ester bond such as a carboxyl group, a hydroxy group, or an alkoxy group. Also included are condensable reactive groups capable of forming In addition, a carboxyl group, a hydroxyl group, etc. function as a polymerizable group only when a group which becomes a reaction (binding) partner is present in another monomer.

  Examples of the (A) monofunctional (meth) acrylate monomer include (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl Alkyl (meth) acrylates such as (meth) acrylate and 2-ethylhexyl (meth) acrylate; cyclopropyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclooctyl Cycloalkyl (meth) acrylates such as (meth) acrylate, cycloundecyl (meth) acrylate, cyclododecyl (meth) acrylate, isobornyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate; 2-hydroxyethyl ( Hydroxyalkyl (meth) acrylates such as (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate; phenyl (meth) acrylate, benzyl (meth) acrylate, tolyl (meth) acrylate, phenethyl Aromatic ring-containing (meth) acrylates such as (meth) acrylates may be mentioned. These (A) monofunctional (meth) acrylate monomers may be used alone or in combination of two or more. Among these, alkyl (meth) acrylates are preferable, and methyl (meth) acrylate is particularly preferable.

  The content of the (A) monofunctional (meth) acrylate monomer is (A) a monofunctional (meth) acrylate monomer, (B) a polyfunctional (meth) acrylate monomer, and (C). Of the total 100% by mass of the styrenic monomers, 30% by mass or more is preferable, more preferably 40% by mass or more, still more preferably 50% by mass or more, particularly preferably 60% by mass or more, and 95% by mass or less. More preferably, it is 90 mass% or less, More preferably, it is 85 mass% or less. (A) If the content of the monofunctional (meth) acrylate monomer is 30% by mass or more, the charge of the polymer particles is suppressed, so that handleability is improved, and if it is 95% by mass or less, When preparing the resin composition or processing the resin composition, deformation of the polymer particles due to melting or heating during processing is suppressed.

(B) Polyfunctional (meth) acrylate monomer The (B) polyfunctional (meth) acrylate monomer has one (meth) acryloyl group in the molecule, and the (meth) acryloyl group. And a monomer having one or more polymerizable groups.
Examples of the (B) polyfunctional (meth) acrylate monomer include allyl (meth) acrylates such as allyl (meth) acrylate; ethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) ) Acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 1,3-butylene di (meth) acrylate, etc. Alkanediol di (meth) acrylate; diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, decaethylene glycol di (meth) acrylate, pentadecaethylene glycol di (meth) acrylate, pentacontactor ethylene glycol di ( Meta Di (meth) acrylates such as polyalkylene glycol di (meth) acrylate such as acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate; trimethylolpropane tri And tri (meth) acrylates such as (meth) acrylate; tetra (meth) acrylates such as pentaerythritol tetra (meth) acrylate; and hexa (meth) acrylates such as dipentaerythritol hexa (meth) acrylate. These (B) polyfunctional (meth) acrylate monomers may be used alone or in combination of two or more. Among these, those having 2 or more (meth) acryloyl groups in one molecule are preferable, and those having 3 or more (meth) acryloyl groups in one molecule are more preferable. Among the polyfunctional (meth) acrylate monomers (B), alkanediol di (meth) acrylates and tri (meth) acrylates are preferable, and ethylene glycol di (meth) acrylate and trimethylolpropane tri are more preferable. (Meth) acrylate.

  The mass ratio ((A) / (B)) between the (A) monofunctional (meth) acrylate monomer and the (B) polyfunctional (meth) acrylate monomer is preferably 1 or more, more preferably. Is 3 or more, more preferably 5 or more, preferably 20 or less, more preferably 10 or less, still more preferably 9 or less. If the said mass ratio is 1 or more, it will become the particle | grains which are excellent in mass reduction start temperature and thermal decomposition start temperature. The reason for this is that if the mass ratio is 1 or more, the double bond that tends to remain due to the (B) polyfunctional (meth) acrylate in the polymerization reaction during production is difficult to remain. This is considered because decomposition starting from the bond is suppressed. Moreover, if the said mass ratio is 20 or less, when preparing a resin composition or processing a resin composition, the deformation | transformation of the polymer particle by the fusion | melting and the heating at the time of a process is suppressed.

(C) Styrene monomer As the (C) styrene monomer, for example, styrene; o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-tert-butyl styrene Alkylstyrenes such as p-phenylstyrene; aromatic ring-containing styrenes such as p-phenylstyrene; halogen-containing styrenes such as o-chlorostyrene, m-chlorostyrene and p-chlorostyrene; hydroxyl group-containing styrenes such as p-hydroxystyrene. Alkoxy styrenes such as p-methoxystyrene; and the like. These (C) styrenic monomers may be used alone or in combination of two or more. Of these, styrene is preferred.

  The content of the (C) styrene monomer is 100 parts by mass in total of the (A) monofunctional (meth) acrylate monomer and the (B) polyfunctional (meth) acrylate monomer. On the other hand, it is preferably 2 parts by mass or more, more preferably 5 parts by mass or more, further preferably 10 parts by mass or more, preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and further preferably 25 parts by mass or less. The amount is particularly preferably 16 parts by mass or less. (C) If content of a styrene-type monomer is 2 mass parts or more, the mass reduction start temperature of a polymer particle will become still higher, and the affinity to an aromatic polyester resin and a dispersibility will also improve. When the content is 100 parts by mass or less, the charge of the polymer particles is suppressed, so that handleability is improved.

(D) Maleimide monomer The polymer particles of the present invention may contain (D) a maleimide monomer as a constituent component. (D) By including a maleimide monomer, the thermal decomposition start temperature of the polymer particles in the non-oxidizing atmosphere can be further increased. Examples of the (D) maleimide monomer include those represented by the general formula (1).

[In Formula (1), R < ¹ > and R < ² > are respectively independently a hydrogen atom, a halogen atom, a C1-C15 alkyl group, a C1-C15 aryl group, or a C1-C15 aralkyl. R ³ represents an alkyl group having 1 to 15 carbon atoms, an aryl group having 1 to 15 carbon atoms, or an aralkyl group having 1 to 15 carbon atoms. ]

Examples of the alkyl group represented by R ^{1 to} R ³ include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group. Linear alkyl groups such as tridecyl group, tetradecyl group and pentadecyl group; branched alkyl groups such as isopropyl group, isobutyl group and tert-butyl group; cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group and the like A cyclic alkyl group is mentioned. Examples of the aryl group represented by R ^{1 to} R ³ include a phenyl group and a naphthyl group. In addition, the hydrogen atom which these alkyl groups and aryl groups have may be further substituted with an alkyl group, aryl group, halogen atom, nitro group or the like. Examples of the aralkyl group represented by R ^{1 to} R ³ include a benzyl group, a phenethyl group, and a 3-phenylpropyl group.

  Specific examples of the (D) maleimide monomer include, for example, maleimide; N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide and the like. N-alkylmaleimide; N-phenylmaleimide, N- (2-chlorophenyl) maleimide, N- (3-chlorophenyl) maleimide, N- (4-chlorophenyl) maleimide, N- (4-bromophenyl) maleimide, N- ( 2,4,6-trichlorophenyl) maleimide, N- (2,4,6-tribromo) maleimide, N- (2-nitrophenyl) maleimide, N- (3-nitrophenyl) maleimide, N- (4-nitro Phenyl) maleimide, N- (2,4-dinitrophenyl) maleimide, N- N-arylmaleimides such as 2-hydroxyphenyl) maleimide, N- (3-hydroxyphenyl) maleimide, N- (4-hydroxyphenyl) maleimide, N- (4-phenylphenyl) maleimide, N-naphthylmaleimide; N- (2-methylphenyl) maleimide, N- (3-methylphenyl) maleimide, N- (4-methylphenyl) maleimide, N- (2-butylphenyl) maleimide, N- (3-butylphenyl) maleimide, N- N-alkylarylmaleimides such as (4-butylphenyl) maleimide and N- (2,6-dimethylphenyl) maleimide; N- (2-methoxyphenyl) maleimide, N- (3-methoxyphenyl) maleimide, N- ( 4-methoxyphenyl) maleimide, N- (4-ethoxyphenyl) Aralkyl maleimide benzyl maleimide; aryloxy arylmaleimide N-(4-phenyloxy-phenyl) maleimide; Reimido, N-(2-methoxy-4-chlorophenyl) alkoxyaryl maleimides such as maleimide and the like. These (D) maleimide monomers may be used alone or in combination of two or more. Among these, N-alkylmaleimide (preferably N-cyclic alkylmaleimide) and N-arylmaleimide are preferable, and N-cyclohexylmaleimide and N-phenylmaleimide are particularly preferable.

  When the (D) maleimide monomer is used, the content of the (D) maleimide monomer is such that the (A) monofunctional (meth) acrylate monomer and the (B) polyfunctional ( 1 part by mass or more is preferable, more preferably 5 parts by mass or more, and still more preferably 10 parts by mass or more, with respect to a total of 100 parts by mass of the (meth) acrylate monomer and (C) styrene monomer. 30 mass parts or less are preferable, More preferably, it is 20 mass parts or less, More preferably, it is 16 mass parts or less. (D) If the content of the maleimide monomer is 1 part by mass or more, the effect of increasing the thermal decomposition start temperature in a non-oxidizing atmosphere by the maleimide monomer can be sufficiently obtained. If present, the colorlessness (whiteness) of the polymer particles is improved.

Other monomers The polymer particles of the present invention are (A) monofunctional (meth) acrylate, (B) polyfunctional (meth) acrylate, and (C) styrenic, as long as the effects of the present invention are not impaired. Another monomer different from the monomer and (D) maleimide monomer may be included as a constituent component. When other monomers are used, the amount used is preferably 20% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less in the total monomers. The polymer particles of the present invention preferably have no other monomer as a constituent component.

Production Method of Polymer Particles The polymer particles of the present invention can be obtained by polymerizing a monomer composition containing the above-described constituent component (monomer component). In addition to the above-described constituent components, the monomer composition includes additives such as pigments, plasticizers, polymerization stabilizers, fluorescent brighteners, magnetic powders, ultraviolet absorbers, antistatic agents, and flame retardants. Further, it may contain a polymerization initiator and a dispersion stabilizer. The polymerization reaction is preferably carried out in a solvent. In this case, the monomer composition prepared in advance may be added to the solvent, or each component, additive, etc. may be added separately to the solvent. And may be mixed in a solvent.

  Here, when producing the polymer particles of the present invention, monomers ((A) monofunctional (meth) acrylate monomers, (B) polyfunctional (meth) acrylate monomers, and (C) A styrene monomer, and further (D) maleimide monomer as required may be referred to as (E) a compound having a thiol group and a carboxyl group (hereinafter simply referred to as “(E) compound”). It is preferable to copolymerize in the presence of (E) By copolymerizing the monomer in the presence of the compound, the thermal decomposition start temperature can be improved while maintaining the mass decrease start temperature in the non-oxidizing atmosphere of the polymer particles obtained.

  The compound (E) is not particularly limited as long as it has one or more thiol groups (—SH) and carboxyl groups (—COOH) in one molecule. Specific examples of the compound (E) include mercaptocarboxylic acids such as those having an aromatic ring such as salicylic acids such as thiosalicylic acid and dithiosalicylic acid. Among these, those having an aromatic ring are preferable, and thiosalicylic acid and dithiosalicylic acid are more preferable.

  The amount of the compound (E) used is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and still more preferably 0.8 parts by mass or more with respect to 100 parts by mass of all monomer components. Yes, preferably 3 parts by mass or less, more preferably 2 parts by mass or less, and still more preferably 1.5 parts by mass or less. If the amount of the (E) compound used is 0.1 parts by mass or more, the thermal decomposition starting temperature in the non-oxidizing atmosphere of the polymer particles is further improved. Derived color is suppressed, and the colorlessness (whiteness) of the polymer particles is also improved.

  As a method for producing the polymer particles of the present invention, known polymerization methods such as emulsion polymerization, suspension polymerization, seed polymerization and the like can be employed. In these polymerization methods, examples of the polymerization solvent include water; alcohols such as methanol, ethanol and isopropyl alcohol; ketones such as acetone and methyl ethyl ketone; aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate. Organic solvents such as the like can be used. Among the above polymerization methods, the suspension polymerization method is preferable because polymer particles having a polymer composition according to the monomer composition of the raw material are easily obtained.

Hereinafter, suspension polymerization will be described as an example of the method for producing polymer particles of the present invention.
Suspension polymerization generally polymerizes a droplet suspension composition obtained by dispersing and suspending a monomer composition containing monomer components and additives in water. This is a method for obtaining a dispersion liquid in which polymer particles are dispersed and contained in water. When preparing the droplet suspension composition, conventionally known dispersion, suspension methods, and apparatuses can be employed as means for suspending the monomer composition in water. For example, T.W. K. A high-speed stirrer such as a homomixer or a line mixer (for example, Ebara Milder (registered trademark)) can be used. Further, in order to control and stabilize the particle diameter of the droplets of the monomer composition, it is preferable that a dispersion stabilizer described later is coexisted when preparing the droplet suspension composition.

  Here, the polymerization initiator (described later) may be present in the suspension composition at the time of the polymerization reaction. However, at the time of preparing the droplet suspension composition, the polymerization initiator is added to the monomer composition phase or the aqueous phase. It is preferable to disperse and dissolve, and an embodiment in which the monomer composition is dissolved in advance is particularly preferable. The polymerization reaction is preferably performed with stirring. For the stirring, stirring using a conventionally known stirring blade such as a paddle blade, a turbine blade, a blue margin blade, or a propeller blade may be employed.

  For the polymerization reaction, a polymerization initiator may be used, or a method of initiating polymerization by applying radiation or applying heat may be employed. As the polymerization initiator, any of those usually used for radical polymerization can be used. For example, a peroxide initiator, an azo initiator, or the like can be used. Examples of the peroxide initiator include benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, orthochlorobenzoyl peroxide, and orthomethoxybenzoyl peroxide. Examples of the azo initiator include dimethyl-2,2′-azobisisobutyrate, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2, And 2'-azobis (2,3-dimethylbutyronitrile). These polymerization initiators are preferably used in an amount of 0.01 to 20 parts by mass (more preferably 0.1 to 10 parts by mass) with respect to 100 parts by mass of the monomer component.

  Further, at the time of the polymerization reaction, a dispersion stabilizer may be used in order to proceed the polymerization reaction stably. Examples of the dispersion stabilizer include water-soluble polymers such as polyvinyl alcohol, gelatin, sodium polyacrylate, polysodium methacrylate; sodium lauryl sulfate, polyoxyethylene alkylphenyl ether sulfate (for example, polyoxyethylene distyrylphenyl) Anionic surfactants such as ether sulfate ammonium); cationic surfactants such as alkylamine salts and quaternary ammonium salts; zwitterionic surfactants such as lauryl dimethylamine oxide; polyoxyethylene alkyl ethers and the like Nonionic surfactant, other alginate, zein, casein, barium sulfate, calcium sulfate, barium carbonate, magnesium carbonate, calcium phosphate, talc, clay, diatomaceous earth, bentonite, titanium hydroxide Thorium hydroxide, metal oxide powder or the like is used.

  What is necessary is just to adjust the usage-amount of the said dispersion stabilizer suitably according to the size of the polymer particle desired. For example, if it is desired to obtain polymer particles having a particle diameter of 1 μm to 20 μm, 0.01 parts by weight to 10 parts by weight (more preferably 0.05 parts by weight to 5 parts by weight) with respect to 100 parts by weight of the monomer component. Part, more preferably 1 part by weight to 2 parts by weight).

  The polymerization temperature is preferably 60 ° C. to 100 ° C. (more preferably 65 ° C. to 95 ° C., more preferably 70 ° C. to 90 ° C.), and the polymerization reaction is 2 hours to 7 hours (more preferably 2.5 hours to 5 hours). And more preferably 3 hours to 4.5 hours). The polymerization reaction is preferably performed in the range of pH 4 to pH 10.

  And a polymer particle is obtained by carrying out solid-liquid separation of the dispersion liquid in which the polymer particle obtained by the polymerization reaction is dispersedly contained in water. Examples of the solid-liquid separation method include filtration and centrifugation.

  Further, a flocculant may be used for solid-liquid separation. As the flocculant, metal salts such as sodium chloride, magnesium chloride, calcium chloride, sodium sulfate, aluminum sulfate, zinc sulfate, magnesium sulfate, sodium hydrogen carbonate, sodium carbonate, ammonium chloride, potassium alum; sulfuric acid, hydrochloric acid, phosphoric acid, Examples thereof include acids such as nitric acid, carbonic acid and acetic acid; alcohols such as methanol and ethanol; These flocculants may be used alone or in combination of two or more.

  The addition amount of the flocculant is not particularly limited, but is 0.05 parts by mass to 10 parts by mass with respect to 100 parts by mass of the polymer particles in the dispersion. The time required for agglomeration is short, and agglomeration usually occurs in the range of 0.1 minute to 2 hours. Therefore, abrupt addition of the flocculant is not preferable because stirring may be impossible, and it is preferable to gradually add the flocculant to the dispersion. The temperature of the dispersion when adding the flocculant is preferably 30 ° C to 100 ° C.

Uses The polymer particles of the present invention have a higher mass reduction start temperature in a non-oxidizing atmosphere than conventional particles. Therefore, the polymer particles of the present invention hardly generate decomposition products when melt-mixed with the resin in a non-oxidizing atmosphere such as a nitrogen atmosphere, and are less likely to cause resin coloring or residual bubbles. It can be suitably used as an additive for use. Examples of the resin to which the polymer particles of the present invention are added include polyester resin, polyolefin resin, polyamide resin, polyurethane resin, (meth) acrylic resin, polycarbonate resin, and polystyrene resin. Among these, when the polymer particles of the present invention are used as an additive for a polyester resin that has a relatively high melting point and needs to be melt-mixed at a high temperature, the effects of the present invention are further exhibited.

  Among the additives for resins, the polymer particles of the present invention are excellent in heat resistance, further suppressed in coloring (excellent in colorlessness), and the refractive index of the polymer particles can be controlled in a relatively wide range depending on the composition. It is useful as a blocking agent and a light diffusing agent. When the polymer particles of the present invention are used as an additive for a resin, the polymer particles may be used alone or in combination with other components.

Masterbatch As described above, the polymer particles of the present invention are useful as an additive for resins. In addition, since the polymer particles of the present invention have a high thermal decomposition temperature in a non-oxidizing atmosphere, the melt processing temperature can be increased and mixing at a lower melt viscosity becomes possible. Therefore, even if the blending amount of the polymer particles with respect to the resin is increased, the polymer particles are easily dispersed uniformly. Therefore, a masterbatch containing the polymer particles of the present invention and a resin is also a preferred embodiment.

  Examples of the resin used for the master batch include polyester resin, polyolefin resin, polyamide resin, polyurethane resin, (meth) acrylic resin, polycarbonate resin, polystyrene resin, and the like. Among these, when the polymer particles of the present invention are used as an additive for a polyester resin that has a relatively high melting point and needs to be melt-mixed at a high temperature, the effects of the present invention are further exhibited. Therefore, the masterbatch containing the polyester additive containing the polymer particles of the present invention and the polyester resin is a preferred embodiment of the present invention.

  The polyester resin is not particularly limited. For example, polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalate, polytetramethylene-2,6-naphthalate. An aromatic polyester resin such as These may be used alone or in combination of two or more. Among these, polyethylene terephthalate resin is preferable.

  The content of the polymer particles in the masterbatch is not particularly limited, but is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and further preferably 5 masses with respect to 100 parts by mass of the resin in the masterbatch. Part or more, preferably 400 parts by weight or less, more preferably 200 parts by weight or less, still more preferably 100 parts by weight or less, and still more preferably 80 parts by weight or less.

  As a method for preparing a masterbatch containing the polymer particles of the present invention, a method in which polymer particles are added and mixed in a polymerization step for synthesizing a resin; a melt-mixing is performed on the polymerized resin using an extruder or the like. A method; a method of adding and mixing polymer particles in a state in which a resin is dissolved in a solvent; Among these, the melt mixing method exhibits the effect of using the polymer particles of the present invention remarkably, and it is easy to produce a resin composition in which polymer particles are dispersed and contained at a high concentration. Suitable for manufacturing.

  As a method of mixing at the polymerization stage for synthesizing the resin, for example, when adding to a polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a glycol component such as ethylene glycol and a dicarboxylic acid (ester) component In the polymerization reaction, there may be mentioned a method in which polymer particles are dispersed in one component (preferably a glycol component) and the polymerization reaction is carried out in the presence of the polymer particles.

  As a method of melt-kneading, for example, a powder or pellet-shaped polyester resin and polymer particles (a form dispersed in a powder or a solvent) are mixed, and the polyester resin is melted with stirring and mixed. And a method in which polymer particles (a form dispersed in a powder or a solvent) are mixed while the polyester resin is melted.

  The prepared master batch is usually processed into a powder form or a pellet form. And a masterbatch is added to resin similar to resin contained in this masterbatch, and it melt-mixes, and a resin composition is prepared. By using the polymer particles of the present invention as an additive, a resin composition in which coloring and generation of bubbles are suppressed can be obtained.

Resin Composition A resin composition containing the polymer particles of the present invention and a resin is also a preferred embodiment. Since the polymer particles of the present invention hardly generate decomposition products when melt-mixed with a resin in a non-oxidizing atmosphere such as a nitrogen atmosphere, a resin composition in which coloring and residual bubbles are suppressed is obtained. It is done. In addition, since the polymer particles of the present invention hardly generate decomposition products even when the resin composition is heat-molded, a resin molded body in which coloring and residual bubbles are suppressed is obtained. The resin composition may be prepared by mixing the masterbatch and the resin, or the resin composition may be directly prepared by mixing the polymer particles of the present invention and the resin.
As a method for molding the resin composition into a film or the like, heat molding such as injection molding or extrusion molding; a method in which the resin composition is diluted with a solvent and the liquid resin composition is applied to a support serving as a base material And the like.

  The method for mixing the polyester resin additive and the polyester resin is not particularly limited, and may be added at the polymerization stage of the polyester resin, or melt-mixed using an extruder or the like to the polyester resin after polymerization. May be.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented within a range that can meet the purpose described above and below. All of which are within the scope of the present invention. In the following, “part” means “part by mass” and “%” means “mass%” unless otherwise specified.

1. Evaluation method 1-1. Volume average particle diameter A particle size distribution measuring device (“Coulter Multisizer III type” manufactured by Beckman Coulter, Inc.) measures the particle diameter of 30000 particles. From the volume-based particle diameter distribution, the volume average particle diameter and the standard particle diameter are measured. While calculating | requiring a deviation, the CV value (variation coefficient) of the particle diameter was computed according to the following formula.
Variation coefficient of particles (%) = 100 × (standard deviation of particle diameter / volume average particle diameter)

1-2. Thermal decomposition evaluation (mass decrease start temperature, thermal decomposition start temperature)
Thermal decomposition evaluation of (meth) acrylic polymer particles was performed 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.) in a nitrogen atmosphere at a flow rate of 20 ml / min. Specifically, using a precision balance, weigh a 15 mg sample into a specified aluminum cup, place the aluminum cup in a predetermined position on the thermal analyzer, and add nitrogen gas (nitrogen purity 99.9% or higher) Was adjusted to flow at a specified flow rate (20 ml / min), and the temperature was increased after the apparatus was stabilized. Then, from the obtained TG (Thermogravimetry) curve, the mass decrease start temperature and the thermal decomposition start temperature were determined as follows. FIG. 1 is a diagram illustrating a method for analyzing a TG curve.
<Mass decrease start temperature>
The change in the mass of the sample is read from the TG curve, the sample mass at 100 ° C. is taken as 100% by mass, and the temperature at which the sample mass is reduced by 1% by mass (the temperature at which the sample mass becomes 99% by mass) is read. Was defined as the mass decrease start temperature. In addition, since it will be included even if the mass reduction resulting from adsorption | suction moisture etc. is included on the basis of the mass in normal temperature, the sample mass in 100 degreeC was made into the reference | standard.
<Pyrolysis start temperature>
For the TG curve, a tangent line of a point at 100 ° C. (one-dot chain line A in the figure) is drawn. Next, an inflection occurs in the portion corresponding to the mass reduction stage where the full-scale thermal decomposition occurs on the higher temperature side than the mass reduction start temperature (the portion where the TG value is −10% to −90%). Draw a tangent at the point (two-dot chain line B in the figure). And temperature T in the intersection of tangent A and tangent B was read, and this temperature was made into thermal decomposition start temperature.

2. 2. Production of polymer particles 2-1. Production Example 1
In a flask equipped with a stirrer, inert gas introduction tube, reflux condenser and thermometer, polyoxyethylene distyryl phenyl ether sulfate ammonium salt ("Hytenol (registered trademark) NF-08", Daiichi Kogyo Seiyaku Co., Ltd.) 300 parts of deionized water in which 2 parts were dissolved, 160 parts of methyl methacrylate (MMA) prepared in advance, 20 parts of trimethylolpropane trimethacrylate (TMPTMA), 20 parts of styrene (St), thiosalicylic acid ( TSA) 2 parts and a mixed solution in which 1 part of lauryl peroxide (LPO) was dissolved were charged. K. The mixture was stirred at 8000 rpm for 10 minutes with a homogenizer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to make a uniform suspension, and 500 parts of deionized water was further added.
Subsequently, it heated until liquid temperature became 65 degreeC, blowing nitrogen gas in a flask, and the reaction container was heat-retained at 65 degreeC. The reaction started when the liquid temperature reached 75 ° C. due to self-heating, and after 90 minutes, the liquid temperature was further raised to 85 ° C. and stirred for 2 hours to complete the polymerization reaction. Thereafter, 0.1 part of aluminum sulfate was added over about 10 seconds at 85 ° C. with stirring. Further, the reaction solution was cooled and filtered, and the polymerization product was dried with hot air at 80 ° C. for 8 hours. 1 was obtained. The obtained polymer particles No. The evaluation results of 1 are shown in Table 1.

2-2. Production Example 2
Production Example 1 except that the monomer components were changed to 140 parts of methyl methacrylate (MMA), 20 parts of trimethylolpropane trimethacrylate (TMPTMA), 20 parts of styrene (St), and 20 parts of phenylmaleimide (PMI). In the same manner as in Polymer Particle No. 2 was obtained. The obtained polymer particles No. The evaluation results of 2 are shown in Table 1.

2-3. Production Example 3
Production Example 1 except that the monomer components were changed to 120 parts of methyl methacrylate (MMA), 20 parts of trimethylolpropane trimethacrylate (TMPTMA), 20 parts of styrene (St), and 40 parts of phenylmaleimide (PMI). In the same manner as in Polymer Particle No. 3 was obtained. The obtained polymer particles No. The evaluation results of 3 are shown in Table 1.

2-4. Production Example 4
In the same manner as in Production Example 1 except that the monomer components were changed to 180 parts of methyl methacrylate (MMA) and 20 parts of trimethylolpropane trimethacrylate (TMPTMA), polymer particles No. 4 was obtained. The obtained polymer particles No. The evaluation results of 4 are shown in Table 1.

  From Table 1, polymer particle No. which mix | blended (C) styrene-type monomer as a structural component of a (meth) acrylate type polymer particle. 1-3 are polymer particle No. which does not mix | blend a styrene-type monomer. Compared to 4, it can be seen that the mass decrease start temperature is increased. Further, polymer particles No. 1 containing (D) maleimide monomer as a constituent component. 2 and 3, the polymer particle No. It can be seen that the pyrolysis temperature is increased compared to 1 and 4.

  The polymer particles of the present invention have a higher mass decrease start temperature in a non-oxidizing atmosphere than conventional particles. Therefore, the polymer particles of the present invention can be suitably used as additives for resins such as antiblocking agents and light diffusing agents.

Claims (6)

Consists of a copolymer containing at least (A) a monofunctional (meth) acrylate monomer, (B) a polyfunctional (meth) acrylate monomer, and (C) a styrene monomer as constituent components,
Polymer particles having a mass reduction start temperature in a non-oxidizing atmosphere of 285 ° C or higher.   The content of the (C) styrene monomer is 100 parts by mass in total of the (A) monofunctional (meth) acrylate monomer and the (B) polyfunctional (meth) acrylate monomer. The polymer particle according to claim 1, which is 2 to 100 parts by mass.   The polymer particles according to claim 1 or 2, wherein a thermal decomposition starting temperature in a non-oxidizing atmosphere is 340 ° C or higher.   A polyester resin additive comprising the polymer particles according to any one of claims 1 to 3.   An antiblocking agent for polyester resins, comprising the polymer particles according to any one of claims 1 to 3.   A masterbatch comprising the polyester resin additive according to claim 4 and a polyester resin.