JP2014001370A - Processing aid for polyolefin resin, polyolefin resin composition and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing aid for a polyolefin resin, having thermal decomposition resistance, which is mixed in a polyolefin resin to provide a polyolefin resin composition having excellent moldability, which provides a molded article having excellent transparency.SOLUTION: A processing aid for a polyolefin resin (A) includes an alkyl methacrylate polymer including 50 mass% or more of alkyl methacrylate (a1) units. A refractive index Ra of the processing aid for a polyolefin resin (A) satisfies 1.490≤Ra≤1.540.

Description

  The present invention relates to a polyolefin resin processing aid, a polyolefin resin composition containing the polyolefin resin processing aid, and a molded article obtained by molding the polyolefin resin composition.

In recent years, polyolefin resins such as polyethylene, polypropylene, and polybutene are one of the general-purpose resins that are most widely used in the fields of automobiles, home appliances, and the like because they have excellent basic properties such as light weight and high rigidity. .
However, the moldability is never satisfactory, and various methods have been proposed to improve the moldability.
In addition, for the purpose of improving productivity, speeding up of molding speed and accompanying molding at high temperatures have become mainstream, so that processing aids formulated for the purpose of improving molding processability are also heat resistant. The demand for degradability is also increasing.

  As a method for solving these problems, Patent Document 1 proposes a method in which an alkyl methacrylate polymer having a mass average molecular weight of 150,000 to 20 million is blended with a polyolefin resin.

  Patent Document 2 proposes a method of blending an acrylic polymer copolymer with a thermoplastic resin.

International Publication No. 2009/060936 Pamphlet JP 2002-249668 A

  However, in the methods proposed in Patent Documents 1 and 2, although the melt tension of the polyolefin resin is improved, sufficient performance cannot be imparted with respect to transparency which is important in each use of the polyolefin resin. Further, the heat decomposability of the polymer to be blended was not sufficient.

  An object of the present invention is to provide a processing aid for polyolefin resin which is excellent in heat-decomposability and gives a polyolefin resin composition having excellent molding processability and excellent transparency of a molded product.

The present invention is a polyolefin resin processing aid (A) containing an alkyl methacrylate polymer containing 50% by mass or more of an alkyl methacrylate (a1) unit, and the refractive index Ra of the polyolefin resin processing aid (A) is And a processing aid (A) for polyolefin resin that satisfies the following formula (1).
1.490 ≦ Ra ≦ 1.540 Formula (1)
The present invention also provides a polyolefin resin composition comprising the polyolefin resin processing aid (A) and the polyolefin resin (B), wherein the refractive index Ra of the polyolefin resin processing aid (A) and the polyolefin resin ( The refractive index Rb of B) relates to a polyolefin resin composition satisfying the following formula (2).
−0.015 ≦ Ra−Rb ≦ 0.015 Formula (2)
Moreover, this invention relates to the molded object obtained by shape | molding the said polyolefin resin composition.

  The processing aid for polyolefin resin of the present invention is excellent in heat decomposability, and is added to the polyolefin resin (B) to give a polyolefin resin composition having excellent moldability. Moreover, the molded object obtained from this polyolefin resin composition is excellent in transparency.

  Hereinafter, the processing aid for polyolefin resin, the polyolefin resin composition and the molded product of the present invention will be described. In the present specification, “(co) polymer” means “homopolymer” or “copolymer”. “(Meth) acrylate” means “acrylate” or “methacrylate”.

  In the present invention, the alkyl methacrylate polymer contains 50% by mass or more of alkyl methacrylate (a1) units. That is, the polymer is a (co) polymer of 50 to 100% by mass of alkyl methacrylate (a1) units and 50 to 0% by mass of other monomer (a2) units.

  Examples of the alkyl methacrylate (a1) used as the raw material for the alkyl methacrylate (a1) unit include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, and sec-butyl methacrylate. , T-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, stearyl methacrylate. These may be used alone or in combination of two or more.

Among these, an alkyl methacrylate having an alkyl group having 2 or more carbon atoms is preferable, an alkyl methacrylate having an alkyl group having 2 to 6 carbon atoms is more preferable, and an alkyl methacrylate having an alkyl group having 4 carbon atoms is more preferable. I-butyl methacrylate is most preferred.
When the carbon number is 2 or more, the dispersibility of the polyolefin resin processing aid (A) in the polyolefin resin (B) is good and the melt tension is excellent. Moreover, it is excellent in the powder handleability of the processing aid for polyolefin resins (A) obtained as carbon number is 6 or less.
When the alkyl methacrylate has an alkyl group having 4 carbon atoms, the dispersibility of the polyolefin resin processing aid (A) in the polyolefin resin (B) is better, the melt tension is better, and i-butyl methacrylate. If so, the dispersibility is further improved and the melt tension is further improved.

  Examples of the other monomer (a2) used as the copolymerizable component include aromatic vinyl monomers such as styrene, α-methylstyrene, and chlorostyrene; benzyl (meth) acrylate; phenyl (meth) acrylate; (Meth) acrylic acid; n-butyl acrylate; methyl acrylate; vinyl cyanide monomers such as (meth) acrylonitrile; vinyl ether monomers such as vinyl methyl ether and vinyl ethyl ether; carboxylic acids such as vinyl acetate and vinyl butyrate Vinyl monomers; olefins such as ethylene, propylene, butylene; 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6,6 -Photostabilizing group-containing monomers such as tetramethylpiperidine. These other monomers (a2) may be used individually by 1 type, and may use 2 or more types together.

Among these, the adjustment range of the refractive index of the alkyl methacrylate polymer is widened, and the thermal decomposition of the alkyl methacrylate polymer is suppressed, so that aromatic vinyl units such as styrene, α-methyl styrene, chlorostyrene, etc. Mer; benzyl (meth) acrylate;
Phenyl (meth) acrylate; n-butyl acrylate is preferred, and styrene is more preferred.

In the present invention, the content of the alkyl methacrylate (a1) unit is 50% by mass or more, preferably 60% by mass or more, in 100% by mass of all the monomer units of the alkyl methacrylate polymer, and 70% by mass. % Or more is more preferable.
When the content of the alkyl methacrylate (a1) unit is 50% by mass or more, the dispersibility of the polyolefin resin processing aid (A) in the polyolefin resin (B) is good, and the melt tension is excellent.

  In the present invention, the mass average molecular weight of the alkyl methacrylate polymer is preferably 150,000 to 10,000,000, more preferably 800,000 to 8,000,000, and most preferably 1,500,000 to 5,000,000. When the mass average molecular weight of the alkyl methacrylate polymer is 150,000 or more, the molding processability when the polyolefin processing aid (A) is blended with the polyolefin resin (B) is excellent. Moreover, when the mass average molecular weight of the alkyl methacrylate polymer is 10 million or less, the dispersibility of the processing aid (A) for polyolefin resin in the polyolefin resin (B) becomes good and the melt tension is excellent. A method for measuring the weight average molecular weight of the alkyl methacrylate polymer will be described later.

  In the present invention, as the alkyl methacrylate polymer, the same polymer may be used alone, or two or more polymers having different compositions, molecular weights, particle sizes, etc. may be used in combination.

Examples of the polymerization method of the alkyl methacrylate polymer of the present invention include emulsion polymerization, soap-free polymerization, fine suspension polymerization, suspension polymerization, bulk polymerization, and solution polymerization.
Among these, emulsion polymerization and suspension polymerization are preferable because the alkyl methacrylate polymer can be obtained in the form of powder or granules.

  The particle structure in the case of polymerization using a polymerization method that can obtain a particle structure such as emulsion polymerization may be a single layer structure or a multilayer structure. When the particle structure is a multilayer structure, it is preferably a three-layer structure or less from the viewpoint of economy.

Examples of the emulsifier used for emulsion polymerization include an anionic emulsifier, a nonionic emulsifier, a polymer emulsifier, and a reactive emulsifier having an unsaturated double bond capable of radical polymerization in the molecule. These may be used alone or in combination of two or more.
Among these, anionic emulsifiers such as sulfonic acid salt compounds, sulfuric acid salt compounds, and phosphate ester salt compounds are preferable.

Examples of the dispersion stabilizer used for suspension polymerization include poorly water-soluble inorganic compounds such as calcium phosphate, calcium carbonate, aluminum hydroxide, and starch silica; nonionic polymer compounds such as polyvinyl alcohol, polyethylene oxide, and cellulose derivatives; Examples include anionic polymer compounds such as (meth) acrylic acid and salts thereof, and copolymers of methacrylic acid esters and methacrylic acid and salts thereof. These may be used alone or in combination of two or more.
Among these, an anionic polymer compound is preferable because the dispersion stability can be maintained with a very small amount.

Examples of the polymerization initiator include persulfate compounds such as potassium persulfate, sodium persulfate, and ammonium persulfate; azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2, 2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, etc. 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis {2-methyl -N- [2- (1-hydroxyethyl)] propionamide}, 2,2′-azobis {2-methyl-N- [2- (1-hydroxybutyl)] propionamide} 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] and its salts, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] and its Salts, 2,2′-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane] and salts thereof, 2,2′-azobis {2- [1- (2-hydroxyethyl) ) -2-imidazolin-2-yl] propane} and salts thereof, 2,2′-azobis (2-methylpropionamidine) and salts thereof, 2
Water-soluble azo compounds such as 2,2′-azobis (2-methylpropyneamidine) and salts thereof, 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] and salts thereof; Examples thereof include organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide; and redox initiators in which the persulfate compounds or organic peroxides are combined with a reducing agent. These may be used alone or in combination of two or more.

  The method for adjusting the mass average molecular weight of the alkyl methacrylate polymer of the present invention is not particularly limited, and examples thereof include a method for adjusting the amount of polymerization initiator used and a method for adjusting the amount of chain transfer agent used. It is done.

  Examples of the chain transfer agent include the following. Mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, n-octyl mercaptan, n-tetradecyl mercaptan, n-hexyl mercaptan, n-butyl mercaptan; halogen compounds such as carbon tetrachloride and ethylene bromide; α-methyl Styrene dimer. These chain transfer agents may be used individually by 1 type, and may use 2 or more types together. The amount of chain transfer agent used can be appropriately adjusted according to the weight average molecular weight of the alkyl methacrylate polymer, the type of chain transfer agent used, the composition ratio of the monomers, and the like.

  The polymer thus produced is usually recovered as a powder. The method for pulverizing the polymer is not particularly limited, and can be appropriately selected depending on the polymerization method. For example, a pulverization method in the case of emulsion polymerization includes a coagulation method, a spray drying method, a centrifugal separation method, a freeze drying method, and the like. Among these powdering methods, the coagulation method and the spray drying method are preferable from the viewpoint of the uniformity of the powder.

  When powdering using the coagulation method, the alkyl methacrylate polymer latex is brought into contact with the coagulant, coagulated with stirring to form a slurry, and dehydrated to dry the alkyl methacrylate polymer powder. Can be obtained. Examples of the coagulant used in the coagulation method include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid; organic acids such as formic acid and acetic acid; inorganic salts such as aluminum sulfate, magnesium sulfate and calcium sulfate; organics such as calcium acetate Examples include salts.

  In the case of pulverization using a spray drying method, the alkyl methacrylate polymer latex is spray-dried with a spray dryer under the conditions of an inlet temperature of 120 to 220 ° C. and an outlet temperature of 40 to 90 ° C. Polymer powder can be obtained. The outlet temperature in the spray drying method is preferably 40 to 90 ° C., more preferably 40 to 80 ° C., because the powder of the alkyl methacrylate polymer is excellent in pulverization into primary particles. .

  When an alkyl methacrylate polymer is polymerized by suspension polymerization, a method of taking out the polymer by filtration is simple.

In the present invention, the processing aid (A) for polyolefin resin contains the aforementioned alkyl methacrylate polymer.
The processing aid for polyolefin resin (A) is a filler, flame retardant, stabilizer, lubricant, foaming agent, etc., as long as the original properties of the polyolefin resin (B) are not impaired in addition to the alkyl methacrylate polymer. Various additives may be further blended. As an additive, the thing similar to the illustration of the additive mix | blended with the polyolefin resin composition mentioned later can be used.
The content of the additive is preferably 30% by mass or less, more preferably 10% by mass or less, in 100% by mass of the total amount of the processing aid (A) for polyolefin resin.
When the content of the additive is 30% by mass or less, the dispersibility of the polyolefin resin processing aid (A) in the polyolefin resin (B) is good, and the melt tension is excellent.

In the present invention, the refractive index Ra of the polyolefin resin processing aid (A) satisfies the following formula (1).
1.490 ≦ Ra ≦ 1.540 (1)

When Ra is 1.490 or more and 1.540 or less, the resulting polyolefin resin composition is excellent in transparency. Ra is preferably 1.495 or more and 1.535 or less, and more preferably 1.500 or more and 1.530 or less.
The refractive index Ra of the polyolefin resin processing aid (A) and the refractive index Rb of the polyolefin resin (B) described later are measured by an Abbe refractometer.

In the present invention, the polyolefin resin (B) is a homopolymer or copolymer of an olefin monomer, a copolymer of a superior amount of an olefin monomer and an inferior amount of a vinyl monomer, an olefin The main component is a copolymer of a monomer and a diene monomer.
Examples of the olefin monomer include ethylene, propylene, 1-butene, 1-hexene, 1-octene, and 1-decene. Among these, ethylene and propylene are preferable from the viewpoint of versatility of the obtained molded body.

Examples of the polyolefin resin (B) include low density polyethylene, ultra low density polyethylene, ultra low density polyethylene, linear low density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, And ethylene-vinyl acetate copolymer. These may be used alone or in combination of two or more.
Among these, polyethylene, polypropylene, an ethylene-propylene copolymer, and an ethylene-vinyl acetate copolymer are preferable from the viewpoint of versatility of the obtained molded body.

Examples of polyethylene include “Novatech HD HJ360” and “Novatech HD”.
“HY420”, “Novatech HD HE421”, “Novatech HD JF313” (trade name, manufactured by Nippon Polyethylene Co., Ltd.); “Hi-X” (trade name, manufactured by Prime Polymer Co., Ltd.); Minebhan "(trade name, manufactured by Sankyo Polyethylene Co., Ltd.).
Examples of the polypropylene include “Novatech PP FY4”, “Novatech PP MG03B”, “Novatech PP MA3”, “Novatech PP BC03B”, “Novatech PP BC06C”, “Wintech”, “Newcon”, “Newformer” "(Trade name, manufactured by Nippon Polypro Co., Ltd.);" Prime Polypro J105G "," Prime Polypro B241 "(trade name, manufactured by Prime Polymer Co., Ltd.).

  The polyolefin resin composition of this invention can be obtained by mixing each structural component.

The content of the polyolefin resin processing aid (A) in the polyolefin resin composition is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the polyolefin resin (B), 0.5 to It is more preferable that it is 10 mass parts.
When the content of the processing aid for polyolefin resin (A) is 0.1 parts by mass or more, the resulting polyolefin resin composition is excellent in melt tension. Moreover, the original characteristic of polyolefin resin (B) is not impaired as content of the processing aid (A) for polyolefin resins is 20 mass parts or less.

  The polyolefin resin composition of the present invention is preferably blended with a crystal nucleating agent (C) because of excellent transparency. The crystal nucleating agent (C) is not particularly limited as long as it is an inorganic compound such as talc, and is generally used as a crystal nucleating agent for polyolefin resins. For example, the sorbitol-based compound and organic phosphoric acid shown below are used. Ester metal salts can be suitably used.

  Examples of sorbitol compounds include 1,3,2,4-dibenzylidene sorbitol, 1,3,2,4-bis (4-methylbenzylidene) sorbitol, 1,3,2,4-bis (4-ethyl). Benzylidene) sorbitol, 1,3,2,4-bis (2 ', 4'-dimethylbenzylidene) sorbitol, 1,3- (4-methylbenzylidene) -2,4-benzylidenesorbitol, 1,3- (2' , 4′-dimethylbenzylidene) -2 · 4-benzylidenesorbitol, 1,3-benzylidene-2 · 4- (2 ′, 4′-dimethylbenzylidene) sorbitol, 1,3,2,4-bis (3 ′, 4′-dimethylbenzylidene) sorbitol, 1 • 3- (4-chlorobenzylidene) -2 • 4- (4-methylbenzylidene) sorbitol, etc. . These can be used alone or in combination of two or more.

  Examples of the organic phosphate metal salt include sodium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate, sodium-2,2′-ethylidene-bis (4,6- Di-t-butylphenyl) phosphate, lithium-2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate, lithium-2,2′-ethylidene-bis (4,6-di-) t-butylphenyl) phosphate, calcium-bis [2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate], magnesium-bis [2,2′-methylene-bis (4,6 -Di-t-butylphenyl) phosphate], aluminum-tris [2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate], 2,2 -Methylenebis (4,6-di-t-butylphenyl) phosphate basic aluminum salt, bis (2,4,8,10-tetra-t-butyl-hydroxy-12H-dibenzo [d, g] [1,3 , 2] dioxaphosphocin-6-oxide) aluminum hydroxide and the like. These can be used alone or in combination of two or more.

  Examples of other crystal nucleating agents include aromatic carboxylic acids and metal salts of aliphatic carboxylic acids. Specific examples include aluminum benzoate, aluminum pt-butylbenzoate, sodium adipate, and thiophene. Examples thereof include sodium carboxylate and sodium pyrolecarboxylate. These can be used alone or in combination of two or more.

The content of the crystal nucleating agent (C) in the polyolefin resin composition is preferably 0.01 to 5 parts by mass, and 0.05 to 3 parts by mass with respect to 100 parts by mass of the polyolefin resin (B). It is more preferable that
When the content of the crystal nucleating agent (C) is 0.01 parts by mass or more, the resulting molded article of the polyolefin resin composition is excellent in transparency. Moreover, the external appearance defect derived from the undispersed thing of the crystal nucleating agent (C) in the molded object of the polyolefin resin composition as the compounding quantity of a crystal nucleating agent (C) is 5 mass parts or less can be suppressed.

In the polyolefin resin composition of the present invention, the refractive index Ra of the polyolefin resin processing aid (A) and the refractive index Rb of the polyolefin resin (B) preferably satisfy the following formula (2).
−0.015 ≦ Ra−Rb ≦ 0.015 (2)

  When the value of Ra—Rb is −0.015 or more and 0.015 or less, the obtained polyolefin resin composition is excellent in transparency. The value of Ra-Rb is preferably from -0.010 to 0.010, more preferably from -0.008 to 0.008.

As a method for mixing the polyolefin resin composition, known melt kneading such as extrusion kneading and roll kneading can be used.
The melt-kneading method is not particularly limited, and the polyolefin resin processing aid (A) of the present invention, the polyolefin resin (B) and, if necessary, the crystal nucleating agent (C) may be melt-kneaded at the same time. Then, a masterbatch is prepared by melt-kneading the polyolefin resin processing aid (A) and, if necessary, the total amount of the crystal nucleating agent (C) and a part of the polyolefin resin (B), and then the masterbatch and the polyolefin. You may melt-knead the remainder of resin (B).

  The melt kneading temperature can be appropriately set according to the type of the polyolefin resin (B). The melt kneading temperature is preferably 160 to 280 ° C, and more preferably 180 to 240 ° C.

The polyolefin resin composition of the present invention may further contain additives such as a filler, a flame retardant, a stabilizer, a lubricant, a foaming agent, an antiblocking agent, and an antistatic agent, as necessary.
The content of these additives in the polyolefin resin composition is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the polyolefin resin (B).
When the content of these additives is 0.01 parts by mass or more, the effects of various additives are excellent, and when the content is 10 parts by mass or less, the original characteristics of the resulting polyolefin resin composition are not impaired.

  The molded product of the present invention is obtained by molding the polyolefin resin composition of the present invention. As a molding method of the molded body of the present invention, a known molding method can be used, and examples thereof include extrusion molding, injection molding, calendar molding, blow molding, thermoforming, foam molding, and melt spinning.

  The molded body of the present invention is suitable for a sheet material such as an optical sheet, a film material such as a food film, an automobile member, a household appliance member, a medical member, and a building member.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. In the examples, “parts” and “%” indicate “parts by mass” and “% by mass”.

(1) Refractive index (1) -1. Measurement of refractive index Ra of processing aid (A) A thin film of about 1 mm in thickness is formed from the powder of processing aid (A) by a heating press method (pressurization 1 minute after 160 ° C preheating 5 minutes and then cooling 2 minutes). Created. The thin film was used and measured with an Abbe refractometer according to JIS K-7105.
(1) -2. Measurement of refractive index Rb of polyolefin resin (B) (1) -1. Was measured in the same manner.

(2) Mass average molecular weight The tetrahydrofuran-soluble content of the alkyl methacrylate polymer was used as a sample and subjected to molecular weight measurement using gel permeation chromatography (GPC).
The measurement conditions of GPC are as follows, and the mass average molecular weight was determined from a calibration curve using standard polystyrene.
Equipment: “HLC8220” manufactured by Tosoh Corporation
Column: “TSKgel SuperMultipore HZ-H” manufactured by Tosoh Corporation (inner diameter 4.6 mm × length 15 cm × 2, exclusion limit 4 × 107 (estimated)),
Eluent: THF,
Eluent flow rate: 0.35 ml / min,
Measurement temperature: 40 ° C.
Sample injection volume: 10 μl (sample concentration 0.1%).

(3) 5% weight loss temperature (heat decomposability)
The obtained processing aid (A) was used as a sample and subjected to measurement using thermogravimetry (TGA).
The TGA measurement conditions were as follows, and the temperature at which the sample weight decreased by 5% was defined as the 5% weight decrease temperature.
Equipment: TG / DTA6200 manufactured by Seiko Instruments Inc.
Sample amount: 10 mg,
Measurement temperature: 40 ° C. → 550 ° C. (temperature increase rate 10 ° C./min),
Atmospheric gas: Chisso,
Gas flow rate: 200 ml / min.

(4) Transparency (Haze)
Using the obtained molded body (100 × 50 × 2 mm test piece), it was measured according to JIS K-7105, and the transparency was judged according to the following criteria: ○: Haze is less than 50% ×: Haze is 50% that's all

(5) Melt Tension Using the obtained polyolefin resin composition, a capillary type rheometer (model name “Twin Capillary Rheometer RH-7”, manufactured by ROSAND) was used to obtain a die diameter = φ1 mm, L / D = 16. The mixture was extruded at a constant amount (1.57 cm 3 / min) under the condition of a temperature of 190 ° C., the strand was taken up at a constant speed (6 m / min), and the melt tension was measured.
Note that the melt tension is one of the indexes for determining the moldability such as extrusion moldability, blow moldability, and foam moldability, and the improvement of the melt tension can be regarded as the improvement of the moldability.

[Example 1]
In a separable flask (capacity 5 liters) equipped with a thermometer, a nitrogen introduction tube, a cooling tube and a stirrer, 300 parts (3000 grams) of ion-exchanged water, 78 parts of i-butyl methacrylate, 2 parts of n-butyl acrylate, styrene 20 parts and 1.1 parts of sodium dodecylbenzenesulfonate were added, and the atmosphere in the flask was replaced with nitrogen by passing a nitrogen stream through the separable flask. Next, the internal temperature was raised to 60 ° C., and 0.15 part of potassium persulfate and 5 parts of deionized water were added. Thereafter, heating and stirring were continued for 2 hours to complete the polymerization, and an alkyl methacrylate polymer latex was obtained.
The obtained alkyl methacrylate polymer latex was cooled to 25 ° C., dropped into 500 parts of 70 ° C. hot water containing 5 parts of calcium acetate, and then heated to 90 ° C. for coagulation. The resulting coagulated product was separated and washed, and then dried at 60 ° C. for 12 hours to obtain an alkyl methacrylate polymer powder.
The resulting alkyl methacrylate polymer powder was used as a polyolefin resin processing aid (A1). Table 1 shows the results of measuring the refractive index, mass average molecular weight, and 5% weight reduction temperature of the polyolefin resin processing aid (A1).

[Examples 2 to 7, Comparative Example 1]
An alkyl methacrylate polymer was obtained in the same manner as in Production Example 1 except that the composition of the monomer component and the amount of the chain transfer agent were changed as shown in Table 1. Here, n-octyl mercaptan was used as a chain transfer agent and charged into a separable flask simultaneously with the monomer.
The obtained alkyl methacrylate polymer powders were used as polyolefin resin processing aids (A2) to (A58). Table 1 shows the results of measuring the refractive index, mass average molecular weight, and 5% weight loss temperature of the polyolefin resin processing aids (A2) to (A58).

The abbreviations in Table 1 are as shown below.
i-BMA: i-butyl methacrylate n-BMA: n-butyl methacrylate n-BA: n-butyl acrylate St: styrene PhMA: phenyl methacrylate BzMA: benzyl methacrylate

[Example 8]
Polypropylene resin (trade name “NOVATEC PP MG03B”, manufactured by Nippon Polypro Co., Ltd., refractive index (Rb): 1.500) 100 parts, polyolefin resin processing aid (A1) 5 parts as polyolefin resin (B) And mixed by hand blending.
Then, melt kneading in a φ25 mm single screw extruder (model name “TP-25”, manufactured by Thermoplastics Industry Co., Ltd., L / D = 20) under the conditions of a screw rotation speed of 30 rpm and a cylinder temperature of 190 ° C. A polyolefin resin composition was obtained. The melt tension of the obtained polyolefin resin composition is shown in Table 2.
The obtained polyolefin resin composition was injection-molded at a molding temperature of 200 ° C. using a 100-t injection molding machine (model name “SE-100DU”, manufactured by Sumitomo Heavy Industries, Ltd.), and a molded body (100 × 50 × 2 mm square plate). Table 2 shows the transparency of the obtained molded body.
Table 2 shows the difference between the refractive index Ra of the polyolefin resin processing aid (A1) and the refractive index Rb of the polyolefin resin (B).

[Examples 9 to 13, Comparative Examples 2 and 3]
A polyolefin resin composition and a molded body were obtained in the same manner as in Example 8 except that the blending composition was changed to the composition described in Table 2. Table 2 shows the melt tension of the obtained polyolefin resin composition and the transparency of the molded product.

The abbreviations in Table 2 are as shown below.
PP-1: Polypropylene (trade name “NOVATEC PP MG03B”, manufactured by Nippon Polypro Co., Ltd.)
Ra: Refractive index of polyolefin resin processing aid (A) Rb: Refractive index of polyolefin resin (B)

[Example 14]
Polypropylene resin (trade name “NOVATEC PP FY4”, manufactured by Nippon Polypro Co., Ltd., refractive index (Rb): 1.500) 100 parts as polyolefin resin (B), sorbitol-based crystal nucleating agent 1 as crystal nucleating agent (C)・ 3,2,4-dibenzylidenesorbitol, 1,3,2,4-bis (4-methylbenzylidene) -D-sorbitol (trade name “Gelol MD”, manufactured by Shin Nippon Rika Co., Ltd.) 0.5 part And the polyolefin resin composition was obtained by the same method as Example 8 except having changed into 5 parts of processing aids (A1) for polyolefin resins. The melt tension of the obtained polyolefin resin composition is shown in Table 3.
A molded body was obtained from the obtained polyolefin resin composition in the same manner as in Example 8. Table 3 shows the transparency of the obtained molded body.
Table 3 shows the difference between the refractive index Ra of the polyolefin resin processing aid (A1) and the refractive index Rb of the polyolefin resin (B).

[Examples 15 to 17, Comparative Examples 4 and 5]
A polyolefin resin composition and a molded body were obtained in the same manner as in Example 14 except that the blending composition was changed to the composition described in Table 3. Table 3 shows the melt tension of the obtained polyolefin resin composition and the transparency of the molded product.

The abbreviations in Table 3 are as shown below.
PP-2: Polypropylene (trade name “Novatech PP FY4”, manufactured by Nippon Polypro Co., Ltd.)
Gelall MD: Sorbitol-based crystal nucleating agent (trade name “Gelall MD”, manufactured by Shin Nippon Rika Co., Ltd.)
Ra: Refractive index of polyolefin resin processing aid (A) Rb: Refractive index of polyolefin resin (B)

As is apparent from Table 1, in Examples 1 to 7 using the processing aid for polyolefin of the present invention, the 5% weight reduction temperature was 240 ° C. or higher. Generally, since the molding temperature of polyolefin is 180 to 240 ° C., the processing aid for polyolefin of the present invention is excellent in thermal decomposition resistance. On the other hand, in Comparative Example 1, which is outside the scope of the present invention, the heat decomposition resistance was poor.
As apparent from Tables 2 and 3, in Examples 8 to 17 using the polyolefin resin composition of the present invention, the melt tension was excellent, and the obtained molded article was also excellent in transparency. On the other hand, in Comparative Examples 2 and 4 in which the refractive index (Ra) of the processing aid for polyolefin resin is smaller than the range of the present invention and the difference in refractive index (Ra-Rb) with the polyolefin resin is large, the melt tension is excellent. Poor body transparency. Moreover, in Comparative Examples 3 and 5 that do not contain the polyolefin resin processing aid (A) of the present invention, the molded article was excellent in transparency but poor in melt tension.

  The processing aid for polyolefin resin of the present invention is excellent in heat decomposability, and the polyolefin resin composition containing the processing aid for polyolefin resin of the present invention is excellent in molding processability and excellent transparency. The body is suitable for automobile members, household appliance members, medical members, building members, and packaging materials.

Claims (7)

A polyolefin resin processing aid (A) containing an alkyl methacrylate polymer containing 50% by mass or more of an alkyl methacrylate (a1) unit, wherein the refractive index Ra of the polyolefin resin processing aid (A) is expressed by the following formula: Processing aid (A) for polyolefin resin that satisfies (1).
1.490 ≦ Ra ≦ 1.540 Formula (1)
The processing aid (A) for polyolefin resin according to claim 1, wherein the unit (a1) is an alkyl methacrylate unit having an alkyl group having 4 carbon atoms.
The processing aid (A) for polyolefin resin according to claim 1, wherein the (a1) unit is an i-butyl methacrylate unit.
The processing aid for polyolefin resin (A) according to any one of claims 1 to 3, wherein the alkyl methacrylate polymer has a mass average molecular weight of 150,000 to 10,000,000.
A polyolefin resin composition comprising the polyolefin resin processing aid (A) and the polyolefin resin (B) according to any one of claims 1 to 4, wherein the polyolefin resin processing aid (A) is refracted. A polyolefin resin composition in which the rate Ra and the refractive index Rb of the polyolefin resin (B) satisfy the following formula (2).
−0.015 ≦ Ra−Rb ≦ 0.015 (2)
Furthermore, the polyolefin resin composition of Claim 5 containing a crystal nucleating agent (C).
The molded object obtained by shape | molding the polyolefin resin composition of Claim 5 or 6.