WO2017090432A1 - ポリプロピレン系樹脂発泡粒子の製造方法、ポリプロピレン系樹脂発泡粒子および型内発泡成形体 - Google Patents
ポリプロピレン系樹脂発泡粒子の製造方法、ポリプロピレン系樹脂発泡粒子および型内発泡成形体 Download PDFInfo
- Publication number
- WO2017090432A1 WO2017090432A1 PCT/JP2016/083280 JP2016083280W WO2017090432A1 WO 2017090432 A1 WO2017090432 A1 WO 2017090432A1 JP 2016083280 W JP2016083280 W JP 2016083280W WO 2017090432 A1 WO2017090432 A1 WO 2017090432A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- polypropylene resin
- particles
- resin
- polypropylene
- mold foam
- Prior art date
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/16—Making expandable particles
- C08J9/18—Making expandable particles by impregnating polymer particles with the blowing agent
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/0061—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof characterized by the use of several polymeric components
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
- C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
- C08J9/122—Hydrogen, oxygen, CO2, nitrogen or noble gases
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/22—After-treatment of expandable particles; Forming foamed products
- C08J9/228—Forming foamed products
- C08J9/232—Forming foamed products by sintering expandable particles
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2203/00—Foams characterized by the expanding agent
- C08J2203/06—CO2, N2 or noble gases
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2205/00—Foams characterised by their properties
- C08J2205/04—Foams characterised by their properties characterised by the foam pores
- C08J2205/052—Closed cells, i.e. more than 50% of the pores are closed
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
- C08J2323/10—Homopolymers or copolymers of propene
- C08J2323/12—Polypropene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2423/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
- C08J2423/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
- C08J2423/04—Homopolymers or copolymers of ethene
- C08J2423/06—Polyethene
Definitions
- the present invention relates to a method for producing expanded polypropylene resin particles. More specifically, the present invention relates to a method for producing expanded polypropylene resin particles that provides a lightweight and high-strength in-mold expanded molded article. The present invention also relates to polypropylene resin expanded particles and in-mold expanded molded articles.
- the polypropylene resin-in-mold foam-molded product obtained by filling polypropylene resin foam particles in a mold and heat-sealing with steam has the lightness and buffering characteristics that are characteristic of a foam, and is optional. Since it can be molded into any shape, it is used in various applications such as returnable boxes and buffer mats. In addition, in comparison with polystyrene resin and polyethylene resin in-mold foam moldings, polypropylene resin in-mold foam moldings are superior in heat resistance, so the changes in shape and physical properties are small even under high temperature conditions. It is also actively used for automotive parts that require advanced physical properties and quality.
- the strength of a foamed molded product in a polypropylene resin mold is generally evaluated as compressive strength. That is, when the in-mold foam molded body is compressed by applying stress, the in-mold foam molded body having a smaller deformation is expressed as having higher strength.
- the compression strength of the in-mold foam molded product is generally proportional to the strength of the polypropylene resin used as the base material when compared with the in-mold foam molded product having the same density. That is, when the strength of the polypropylene resin (B) is higher than that of the polypropylene resin (A), the compression strength of the in-mold foam molded body (B ′) having the same density made of the polypropylene resin (B) is polypropylene-based.
- the flexural modulus is an index for the strength of the polypropylene resin. Therefore, a polypropylene resin having a high flexural modulus is used to improve the strength of the in-mold foam molding.
- the inventors of the present invention have studied high foaming (weight reduction) and high strength of the in-mold foam molded body based on a pressure-reducing foaming process using an inorganic foaming agent such as carbon dioxide as a foaming agent. It was.
- carbon dioxide gas has been selected because it has a low environmental impact and is extremely safe compared to organic volatile blowing agents such as butane and chlorofluorocarbons.
- organic volatile blowing agents such as butane and chlorofluorocarbons.
- the foaming process using carbon dioxide gas is inferior in foaming power as compared with the case of using an organic volatile foaming agent such as butane and chlorofluorocarbons, it is difficult to achieve high foaming.
- Various high foaming techniques have been proposed so far in order to achieve weight reduction by a foaming process using carbon dioxide gas.
- polypropylene resin particles are dispersed in a dispersion medium in a pressure resistant container, heated to a temperature higher than the temperature at which the polypropylene resin particles are softened, pressurized, and then opened at one end of the pressure resistant container.
- the first expanded particles (hereinafter referred to as “single-stage expanded particles”) obtained by releasing the system resin particles into an atmosphere at a lower pressure than in the pressure-resistant container (hereinafter referred to as “single-stage expanded”), After impregnating with a foaming agent such as air again to give foaming power, it is further foamed by heating with steam or the like (hereinafter this process is referred to as “two-stage foaming”), and has a higher foaming ratio than the original foamed particles.
- a method for obtaining polypropylene resin expanded particles (hereinafter referred to as “two-stage expanded particles”) is disclosed.
- Patent Document 2 discloses that in the one-stage foaming process, polypropylene resin particles impregnated with carbon dioxide in a pressure-resistant container are released and foamed in a high-temperature atmosphere of 80 to 100 ° C., thereby achieving a high foaming ratio. It is disclosed that single-stage expanded particles can be obtained.
- Patent Document 3 by using a polypropylene resin composition in which a large amount of a polypropylene resin and a specific polyethylene resin as a melt tension improver is added, foamed particles having large and uniform bubbles and in-mold It is disclosed that a foamed molded product can be obtained.
- Patent Document 4 discloses a foam using a propylene polymer resin composition obtained by adding a specific ethylene polymer resin to a propylene polymer resin, as in Patent Document 3.
- Patent Document 5 discloses that by adding a specific polyethylene-based resin to a polypropylene-based resin, expanded particles having improved fusing property in in-mold foam molding can be obtained.
- Japanese Patent Publication Japanese Unexamined Patent Application Publication No. 2009-256410 (published on November 5, 2009)” International Publication Gazette “WO2014 / 136933 (published on September 12, 2014)” Japanese Patent Publication “Japanese Patent Laid-Open No. 2010-275499 (Released on Dec. 9, 2010)” Japanese Patent Publication “Japanese Patent Laid-Open No. 2010-265449 (published on November 25, 2010)” International Publication Gazette “WO2009 / 047998 (published on April 16, 2009)”
- the present invention is a mold that makes use of the original strength of the base resin without losing physical properties and quality such as fusion and surface properties at the time of in-mold foam molding, even for polypropylene resin expanded particles with a high expansion ratio. It aims at providing the manufacturing method of the polypropylene resin expanded particle which provides an inner foaming molding.
- the present inventor has one-stage foaming with less wrinkles using polypropylene resin particles made of a polypropylene resin composition in which a specific polyethylene resin is mixed with a polypropylene resin. It has been found that by producing particles, an in-mold foam molded article having high compressive strength can be obtained even if the in-mold foam molded article is reduced in weight. That is, this invention consists of the following structures.
- polypropylene resin (X) 100 parts by weight, obtained by mixing a density 0.945 g / cm 3 or more 0.980 g / cm 3 less than the polyethylene-based resin (Y) one or more parts 10 parts by weight or less
- the polypropylene resin (Z) is made of expanded particles having an expansion ratio of 10 times or more and less than 20 times.
- polypropylene resin expanded particles with a high expansion ratio can utilize the original strength of the base resin without losing physical properties and quality such as fusion and surface properties during in-mold foam molding.
- Tmh of this invention Example 1 in a DSC curve It is a figure which shows Tc of this invention Example 1 in a DSC curve. It is a figure which shows an example of the relationship (used when evaluating the intensity
- Method for producing a polypropylene resin (Z) foaming particles of an embodiment of the present invention is to polypropylene-based resin (X) 100 parts by weight, a polyethylene of density less than 0.945 g / cm 3 or more 0.980 g / cm 3
- Polypropylene resin (Z) particles having a high-temperature side crystal melting peak temperature of 146 ° C. or more and 160 ° C. or less obtained by mixing 1 part by weight or more and 10 parts by weight or less of resin (Y) are dispersed in an aqueous dispersion medium in a pressure resistant container.
- the expanded polypropylene resin (Z) particles have an expansion ratio of 20 to 40 times, closed cells of 90% or more, and wrinkle shrinkage of 5% or less, and the expanded polypropylene resin (Z) particles It is characterized by being manufactured by a single foaming process.
- the wrinkle shrinkage rate By using single-stage expanded particles in which the content is suppressed to 5% or less, an in-mold expanded molded article having a high compressive strength can be obtained even though it is lightweight.
- the strength of the polypropylene resin itself is measured in the region where the polypropylene resin in-mold foam molded article has a high expansion ratio, for example, the density of the in-mold foam molded article is 30 g / L or less. In some cases, the maximum strength of the inner foamed molded article could not be utilized. In other words, the strength of the resin itself correlates with the strength of the in-mold foam molded product in the region where the in-mold foam molded product has a low foaming ratio, whereas in the high foam ratio, the strength is lower than expected from the correlation. There was a thing.
- the foamed particles use an organic volatile foaming agent such as butane, and there is no description regarding an inorganic foaming agent such as carbon dioxide. Moreover, there is no description regarding the compressive strength of the in-mold foam-molded article, which is one of the problems of this case. Moreover, there is no description regarding the closed cells of the expanded particles related to the compressive strength.
- the closed cell ratio described in the examples is around 70%.
- the strength of a foamed polypropylene resin mold depends on the closed cell ratio. When the closed cell ratio is less than 90%, many of the cell membranes are broken, so that the strength of the in-mold foam molded product is low.
- Patent Document 5 it has not been clarified about a problem that the strength of the in-mold foam-molded body in the high expansion ratio region may be lower than the value expected from the strength of the polypropylene resin as a raw material.
- the polypropylene resin (X) used in one embodiment of the present invention is not particularly limited, and is a polypropylene homopolymer, ethylene / propylene random copolymer, butene-1 / propylene random copolymer, ethylene / butene-1 / Propylene random copolymer, ethylene / propylene block copolymer, butene-1 / propylene block copolymer, propylene-chlorinated vinyl copolymer and propylene / maleic anhydride copolymer.
- ethylene / propylene random copolymer, butene-1 / propylene random copolymer or ethylene / butene-1 / propylene random copolymer has good foamability and good moldability. To preferred.
- the ethylene / propylene random copolymer, butene-1 / propylene random copolymer, or ethylene / butene-1 / propylene random copolymer has a comonomer content of a polymerization component other than propylene of 100% by weight of each copolymer. Among them, those having a content of 0.2% by weight to 10% by weight are preferably used.
- the polymerization catalyst for synthesizing the polypropylene resin (X) used in one embodiment of the present invention is not particularly limited, and a Ziegler catalyst, a metallocene catalyst, or the like can be used.
- the melting point of the polypropylene resin (X) used in one embodiment of the present invention is preferably 145 ° C. or higher and 160 ° C. or lower, considering the high temperature side crystal melting peak temperature Tmh of the polypropylene resin (Z) described later.
- the temperature is more preferably 155 ° C. or lower.
- the method for obtaining the melting point is the same as the method for obtaining Tmh described later.
- a bending elastic modulus is 1400 Mpa or more. If the strength of the polypropylene resin (X) is sufficient, the polypropylene resin (Z) also tends to have sufficient strength, and it is easy to suppress wrinkle shrinkage of the expanded particles even in a high expansion ratio region.
- the melt index (hereinafter referred to as “MI”) of the polypropylene-based resin (X) used in one embodiment of the present invention is not particularly limited, but when it is 5 g / 10 min or more and 15 g / 10 min or less, it is independent at a high expansion ratio. It becomes easy to obtain expanded particles and in-mold expanded molded articles having a high cell ratio.
- the MI value is a value measured under the conditions of a load of 2160 g and 230 ⁇ 0.2 ° C. in accordance with JIS K7210.
- the polyethylene resin (Y) used in one embodiment of the present invention may contain a comonomer copolymerizable with ethylene in addition to ethylene as long as it has a predetermined density.
- an ⁇ -olefin having 3 to 18 carbon atoms can be used as the comonomer copolymerizable with ethylene.
- the ⁇ -olefin having 3 to 18 carbon atoms include propene, 1-butene, 1-pentene, 1-hexene, 3,3-dimethyl-1-butene, 4-methyl-1-pentene, 4, 4-dimethyl-1-pentene, 1-octene and the like may be mentioned, and these may be used alone or in combination of two or more.
- Density of the polyethylene resin (Y) in an embodiment of the present invention is less than 0.945 g / cm 3 or more 0.980 g / cm 3, preferably 0.960 g / cm 3 or more 0.980 g / cm less than 3 It is.
- the density of the polyethylene resin (Y) is less than 0.945 g / cm 3 , the effect of suppressing the wrinkle shrinkage of the expanded particles is not sufficiently exhibited.
- the density of the polyethylene resin (Y) exceeds 0.980 g / cm 3 , the polypropylene resin (Z) becomes brittle, and there is a concern that the impact strength of the in-mold foam molded product may be reduced.
- the resin-based resin (Z) foamed particles are difficult to extend and the in-mold foam moldability may be lowered.
- the melting point of the polyethylene resin (Y) used in one embodiment of the present invention is not particularly limited, but those having a temperature of 125 ° C. or higher and 140 ° C. or lower are preferably used.
- the MI of the polyethylene resin (Y) used in one embodiment of the present invention is not particularly limited, but is preferably about the same as that of the polypropylene resin (X).
- the mixing ratio of the polypropylene resin (X) and the polyethylene resin (Y) is polyethylene based on 100 parts by weight of the polypropylene resin (X).
- the resin (Y) is 1 to 10 parts by weight, preferably 2 to 8 parts by weight.
- the mixing ratio of the polyethylene-based resin (Y) is less than 1 part by weight, the effect of suppressing wrinkle shrinkage of the expanded particles is not sufficiently exhibited.
- the mixing ratio of the polyethylene-based resin (Y) exceeds 10 parts by weight, the expansion of the foamed particles at the time of in-mold molding may be deteriorated, or the closed cells of the in-mold foam-molded product may be decreased.
- the high temperature side crystal melting peak temperature Tmh of the polypropylene resin (Z) used in one embodiment of the present invention is preferably 146 ° C. or higher and 160 ° C. or lower.
- the high temperature side crystal melting peak temperature Tmh of the polypropylene resin (Z) is less than 146 ° C., the wrinkle shrinkage of the expanded particles may occur in the high expansion ratio region.
- the high temperature side crystal melting peak temperature Tmh exceeds 160 ° C., the in-mold foam moldability may deteriorate.
- the crystallization temperature Tc of the polypropylene resin (Z) used in one embodiment of the present invention is preferably higher than the crystallization temperature Tcx of the polypropylene resin (X).
- Tcx the crystallization temperature
- a bending elastic modulus is 1400 Mpa or more.
- the MI of the polypropylene resin (Z) used in one embodiment of the present invention is not particularly limited, but when it is 5 g / 10 min or more and 15 g / 10 min or less, the foamed particles and the mold have a high expansion ratio and a high closed cell ratio. It becomes easy to obtain a foam molded article.
- various additives can be added within a range not impairing the effects of the present invention.
- the additive include a water absorbing agent and a cell nucleating agent. , Antioxidants, light resistance improvers and flame retardants.
- water absorbing agent examples include polyethylene glycol, glycerin [chemical name 1,2,3-propanetriol] and melamine [chemical name 1,3,5-triazine-2,4,6-triamine]. It is not limited to these. Particularly preferred water-absorbing agents include polyethylene glycol and glycerin.
- the amount of the water-absorbing agent added is preferably 0.01 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the polypropylene resin (X).
- the amount is 0.01 parts by weight or more, the effect of adding the water-absorbing agent is likely to appear, and when the amount is 10 parts by weight or less, wrinkle shrinkage hardly occurs in the expanded particles.
- cell nucleating agent examples include, but are not limited to, talc, kaolin, barium sulfate, zinc borate and silicon dioxide.
- antioxidants examples include, but are not limited to, phenolic antioxidants and phosphorus antioxidants.
- Examples of the light resistance improver include, but are not limited to, hindered amine light resistance improvers.
- flame retardant examples include, but are not limited to, halogen flame retardants, phosphorus flame retardants, hindered amine flame retardants, and the like.
- the polypropylene resin (Z) is usually melt-kneaded in advance using an extruder, kneader, Banbury mixer, roll, or the like so as to be easily used for foaming, and is cylindrical, elliptical, spherical. It is preferable to mold into a desired particle shape such as a cubic shape, a rectangular parallelepiped shape, a cylindrical shape (straw shape), or the like to obtain polypropylene resin (Z) particles.
- the shape of the polypropylene resin (Z) particles is not necessarily the shape of the polypropylene resin (Z) expanded particles.
- the polypropylene resin (Z) particles may shrink in the foaming process.
- spherical polypropylene resin (Z) foam particles are obtained from the cylindrical or elliptical polypropylene resin (Z) particles. There is a case.
- polypropylene resin (Z) particles from the viewpoint of productivity, it is melt-kneaded with an extruder, extruded into a strand shape from the tip of the extruder, and then cut to form polypropylene resin (Z) particles. More preferably.
- the weight per one polypropylene resin (Z) particle in one embodiment of the present invention is preferably 0.1 mg to 100 mg, more preferably 0.3 mg to 10 mg.
- a sufficient expansion ratio tends to be obtained when the polypropylene resin (Z) particles are expanded.
- the weight per one polypropylene resin (Z) particle is an average resin particle weight obtained from 100 particles obtained by randomly selecting the polypropylene resin (Z) particles.
- the weight per one polypropylene resin (Z) particle hardly changes even after the foaming step, and the weight per one polypropylene resin (Z) particle is equal to the polypropylene resin (Z). There is no problem as the weight per one of the expanded particles.
- the expanded polypropylene resin (Z) particles according to an embodiment of the present invention can be produced using the expanded polypropylene resin (Z) particles thus obtained.
- the polypropylene resin (Z) expanded particles according to an embodiment of the present invention can be manufactured as follows.
- the polypropylene resin (Z) particles, an aqueous medium, an inorganic dispersant, a foaming agent and the like are accommodated in a pressure vessel and dispersed under stirring conditions, and the softening point temperature of the polypropylene resin (Z) particles.
- the polypropylene resin (Z) particles are impregnated with a foaming agent while the temperature is increased and the pressure is higher than the saturated water vapor pressure at that temperature. Thereafter, if necessary, the temperature after the temperature rise is maintained for more than 0 minutes and not more than 120 minutes, and then the dispersion in the pressure vessel is discharged to a pressure region lower than the internal pressure of the pressure vessel, and the polypropylene resin (Z ) Expanded particles can be produced.
- the pressure region lower than the internal pressure of the pressure vessel is preferably atmospheric pressure.
- a single foaming process until the dispersion is released from a pressurized state to a lower pressure region is referred to as a “single-stage foaming process”.
- the obtained polypropylene resin (Z) expanded particles are referred to as “one-stage expanded particles”.
- the dispersion is a mixed liquid in which polypropylene resin (Z) particles, an aqueous medium, an inorganic dispersant, a foaming agent, and the like are contained in a pressure vessel and dispersed under stirring conditions.
- the pressure-resistant container used at the time of producing the polypropylene resin (Z) expanded particles there is no particular limitation on the pressure-resistant container used at the time of producing the polypropylene resin (Z) expanded particles, as long as it can withstand the pressure in the container and the temperature in the container, for example, an autoclave type A pressure vessel is mentioned.
- the temperature in the pressure vessel is raised to the softening point temperature or higher, the temperature is the high temperature side crystal melting peak temperature of the polypropylene resin (Z) particles ⁇ 20 ° C. or higher, and the polypropylene resin (Z) particles. It is preferable to raise the temperature to a temperature in the range of the high temperature side crystal melting peak temperature + 10 ° C. or less in order to ensure foamability. In one embodiment of the present invention, the temperature rising temperature is preferably in the range of 126 ° C. or higher and 170 ° C. or lower. However, the types of polypropylene resin and polyethylene resin used as raw materials, types of foaming agents, and desired foaming are used. It is appropriately determined depending on the magnification and the like.
- aqueous medium used in one embodiment of the present invention for example, water, alcohol, ethylene glycol and / or glycerin can be used alone or in combination. From the viewpoint of foamability, workability or safety, etc. Water is preferably used, and water is most preferably used alone. In the present specification, the aqueous medium is also referred to as “aqueous dispersion medium”.
- the amount of the aqueous medium can be used as 50 parts by weight or more and 500 parts by weight or less, preferably 100 parts by weight or more and 350 parts by weight or less with respect to 100 parts by weight of the polypropylene resin (Z) particles.
- the amount of the aqueous medium can be used as 50 parts by weight or more and 500 parts by weight or less, preferably 100 parts by weight or more and 350 parts by weight or less with respect to 100 parts by weight of the polypropylene resin (Z) particles.
- the amount of the aqueous medium can be used as 50 parts by weight or more and 500 parts by weight or less, preferably 100 parts by weight or more and 350 parts by weight or less with respect to 100 parts by weight of the polypropylene resin (Z) particles.
- coalescence of a plurality of polypropylene resin (Z) particles can be prevented in the pressure vessel, and in the case of 500 parts by weight or less, productivity can be prevented from being lowered, which is preferable from the viewpoint of manufacturing. .
- Examples of the inorganic dispersant used in an embodiment of the present invention include tribasic calcium phosphate, tribasic magnesium phosphate, basic magnesium carbonate, calcium carbonate, basic zinc carbonate, aluminum oxide, iron oxide, titanium oxide, Examples thereof include aluminosilicate, kaolin and barium sulfate, and these can be used alone or in combination. From the viewpoint of the stability of the dispersion, tricalcium phosphate, kaolin, or barium sulfate is preferred. By maintaining the stability of the dispersion, the plurality of polypropylene resin (Z) particles can be prevented from coalescing or lumping in the pressure vessel.
- fused polypropylene resin (Z) expanded particles can be obtained, polypropylene resin (Z) expanded particles cannot be produced due to remaining lump of polypropylene resin (Z) particles in the pressure-resistant container, and polypropylene resin. (Z) It is possible to prevent such a situation that the productivity of the expanded particles is lowered.
- a dispersion aid in order to increase the stability of the dispersion in the pressure vessel.
- the dispersion aid include anionic surfactants. Specific examples include sodium dodecylbenzenesulfonate, sodium alkanesulfonate, sodium alkylsulfonate, sodium alkyldiphenyl ether disulfonate, and ⁇ -olefin sulfonic acid. Sodium etc. are mentioned. A specific example of sodium alkyl sulfonate is normal paraffin sulfonic acid soda.
- the amount of the inorganic dispersant and / or dispersion aid used varies depending on the type and the type and amount of polypropylene resin (Z) particles used, but is usually inorganic based on 100 parts by weight of the aqueous medium.
- the dispersant is preferably 0.1 to 5 parts by weight, and the dispersion aid is preferably 0.001 to 0.3 parts by weight.
- coalescence of a plurality of polypropylene resin (Z) particles in a pressure vessel can be inhibited.
- the amount of the dispersant remaining on the surface of the expanded polypropylene resin (Z) particles is increased, and it is possible to prevent the fusion between the expanded polypropylene resin (Z) particles in the molding described later, which is preferable. .
- blowing agent used in one embodiment of the present invention examples include organic blowing agents such as propane, normal butane, isobutane, normal pentane, isopentane, hexane, cyclopentane, and cyclobutane, and carbon dioxide, water, air, and the like.
- organic blowing agents such as propane, normal butane, isobutane, normal pentane, isopentane, hexane, cyclopentane, and cyclobutane
- carbon dioxide water, air, and the like.
- Inorganic foaming agents such as nitrogen are listed. These foaming agents may be used alone or in combination of two or more.
- foaming agents isobutane or normal butane is excellent from the viewpoint of easily improving the expansion ratio, but these foaming agents are flammable, and it is necessary to make the equipment used an explosion-proof structure. There are caveats. From the viewpoint of safety, it is preferable to use an inorganic foaming agent such as carbon dioxide, water, air or nitrogen, and most preferably a foaming agent containing carbon dioxide.
- the amount of the foaming agent is not limited, and may be appropriately used depending on the desired expansion ratio of the polypropylene resin (Z) expanded particles.
- the polypropylene resin (Z ) It is preferably 2 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight of the particles.
- the expansion ratio of the expanded polypropylene resin (Z) particles used in an embodiment of the present invention is 20 times to 40 times, preferably 25 times to 40 times.
- the expansion ratio is less than 20 times, the problem of the present invention hardly occurs.
- the expansion ratio exceeds 40 times, it may be difficult to obtain single-stage expanded particles with suppressed wrinkle shrinkage according to the present invention.
- the following method is known as a method for obtaining polypropylene resin (Z) expanded particles having a high expansion ratio of 20 to 40 times in the one-stage expansion process.
- a method of using a large amount of an organic foaming agent, an inorganic foaming agent, or a mixed foaming agent thereof can be obtained by composite foaming utilizing the foaming power of carbon dioxide and water.
- the water-absorbing agent can be added to the polypropylene resin (Z).
- the temperature of the low pressure region (hereinafter referred to as “foaming atmosphere”) that discharges the dispersion liquid (hereinafter referred to as “foaming atmosphere temperature”) is maintained at a high temperature.
- Foaming atmosphere temperature is preferably 90 ° C. or higher and 105 ° C. or lower, and more preferably 95 ° C. or higher and 105 ° C. or lower. If the foaming atmosphere temperature is 90 ° C. or higher, the effect of improving the magnification of the foamed particles is sufficiently obtained, and if it is 105 ° C.
- the agglomeration of the foamed particles can be suppressed.
- the agglomeration refers to a phenomenon in which foamed particles in a state where the resin on the surface is melted adhere to each other and become an aggregated state.
- polypropylene resin (Z) foamed particles having a high foaming ratio of 20 times or more and 40 times or less in the one-stage foaming step As a method of obtaining polypropylene resin (Z) foamed particles having a high foaming ratio of 20 times or more and 40 times or less in the one-stage foaming step, the foaming agent, the additive, and the foaming atmosphere temperature are appropriately combined. Good.
- the closed cell ratio of the polypropylene resin (Z) expanded particles used in one embodiment of the present invention is 90% or more. When the number of closed cells is less than 90%, many of the cell membranes are broken, so that the strength of the in-mold foam molded product may be lowered.
- the wrinkle shrinkage of the polypropylene resin (Z) expanded particles used in one embodiment of the present invention is 5% or less.
- the wrinkle shrinkage ratio is the ratio of the volume (v) in which the volume is reduced by wrinkles with respect to the maximum volume (v ′) in the expanded particles having the same surface area, as described in Examples below.
- the wrinkle shrinkage of the expanded particles means one-stage expansion, that is, immediately after the heated polypropylene-based resin (Z) particles are discharged into an atmosphere at a lower pressure than in the pressure resistant container, the expanded particles having a high closed cell ratio are in a softened state.
- solidifying it refers to a phenomenon in which the foam particles shrink due to condensation of moisture in the foam particles and a decrease in internal pressure due to a change in gas volume, and wrinkles enter the foam particles.
- the wrinkles of the expanded particles indicate that the resin film constituting the expanded particles is buckled.
- the expansion ratio of the expanded polypropylene resin (Z) particles is 20 times or more, the resin film is likely to buckle when the present invention is not used.
- the present invention clarifies that if there is a buckling history in the resin film constituting the expanded particles, the strength of the in-mold expanded molded body is lower than the strength expected from the polypropylene resin as a raw material. By suppressing wrinkle shrinkage, which is a bending history, it is possible to provide an in-mold foam-molded product that does not decrease in strength even at a high foaming ratio.
- the expansion ratio is increased by foaming again the polypropylene-based resin (Z) expanded particles (single-stage expanded particles) obtained in the single-stage expansion process. It is possible.
- single-stage expanded particles are produced by decompression foaming, and the single-stage expanded particles are placed in a pressure-resistant container and applied at a pressure of 0.1 MPa (gauge pressure) or higher and 0.6 MPa (gauge pressure) or lower with nitrogen, air, or carbon dioxide gas.
- the single-stage expanded particles can be further foamed by heating with steam or the like to increase the expansion ratio.
- Such a single-stage expanded particle is further expanded in a separate process, and the process of increasing the expansion ratio is called a “two-stage expanded process”.
- the resulting polypropylene-based resin (Z) expanded particles are referred to as “two-stage expanded particles”. Call it.
- this two-stage foaming process is a process in which the first-stage foamed particles are foamed and stretched at a lower temperature (about 100 to 120 ° C. and a vapor pressure of 0.10 MPa (gauge pressure) or less) compared to the one-stage foaming process. Since the resin film is stretched in a state where the property is low, the resin film of the two-stage expanded particles tends to be locally thinned and distorted. For these reasons, generally, when the double-stage expanded particles have a particularly high expansion ratio, physical properties such as desired compression strength may not be obtained as compared with the single-stage expanded particles of the same ratio. On the other hand, since the polypropylene resin (Z) expanded particles according to an embodiment of the present invention are single-stage expanded particles obtained by a single-stage expansion process, it is easy to obtain physical properties such as desired compression strength.
- the polypropylene resin (Z) expanded particles according to an embodiment of the present invention become a polypropylene resin in-mold foam-molded product by performing general in-mold foam molding.
- the polypropylene resin (Z) foamed particles are used for in-mold foam molding
- an inorganic gas such as air
- Method c) Conventionally known methods such as a method of filling foamed particles in a mold in a compressed state and molding may be used.
- the polypropylene resin (Z) foamed particles may be produced by, for example, a method of producing a foamed molded product in a polypropylene resin mold.
- the polypropylene resin may be contained in a mold that can be closed but cannot be sealed.
- Polypropylene resin (Z) expanded particles are fused together.
- the mold is cooled with water, cooled to such an extent that the deformation of the in-mold foam molded body after taking out the in-mold foam molded body can be suppressed, and then the mold is opened to obtain an in-mold foam molded body.
- the in-mold foam molded body produced by the above-described method or the like preferably has an in-mold foam molded body density (also referred to as an apparent density) of 15 g / L or more and 30 g / L or less. If the in-mold foam molding density is 15 g / L or more, it is generally easy to obtain a good in-mold foam molding with little deformation and shrinkage. If the density of the in-mold foam molded product is 30 g / L or less, the effect of suppressing the decrease in the strength of the in-mold foam molded product is more prominent.
- the in-mold foam molding density may be 15 g / L or more and less than 25 g / L.
- the in-mold foam molding density is a value obtained by dividing the weight of the in-mold foam molding by the volume of the in-mold foam molding.
- the volume of the in-mold foam-molded product is calculated from the outer dimensions when the in-mold foam-molded product has a simple rectangular parallelepiped shape. Submerged volume (obtained as load obtained as buoyancy when submerged foam molded product is submerged in water / (density of water ⁇ gravity acceleration)) Measured as such.
- the in-mold foam molding density and compressive strength of the in-mold foam molding according to an embodiment of the present invention are preferably equal to or higher than the pass / fail judgment line shown in FIG.
- the pass / fail judgment line is determined by the following procedure.
- Polypropylene resin (Z) foaming with a foaming ratio of 10 times or more and less than 20 times using a polypropylene resin (Z) having the same composition as the raw material of the in-mold foam molded product to be evaluated Make particles.
- a sample of the in-mold foam molded body made of the polypropylene resin (Z) foam particles is prepared.
- the production method of the polypropylene resin (Z) expanded particles and the in-mold expanded molded body is as described above.
- the measuring method of the in-mold foam molding density is as described above.
- the compressive strength for example, 50% compressive stress can be used as an index, but is not limited as long as it is a known index.
- a primary approximation line passing through the origin of the coordinate plane is drawn (broken line in FIG. 3).
- the primary approximation line can be determined by a known regression line derivation method (such as the least square method).
- the in-mold foam molded body density and compressive strength of the in-mold foam molded body according to an embodiment of the present invention are measured, and the points plotted on the coordinate plane are equal to or higher than the pass / fail judgment line determined by the above procedure. In this case, it is preferable that the compression strength is not excessively lowered by increasing the expansion ratio.
- “beyond the pass / fail judgment line” means that the plotted point is on the pass / fail judgment line, and a case where the plotted point is above the pass / fail judgment line (circled area in FIG. 3).
- the present invention may have the following configuration.
- polypropylene resin (X) 100 parts by weight, obtained by mixing a density 0.945 g / cm 3 or more 0.980 g / cm 3 less than the polyethylene-based resin (Y) one or more parts 10 parts by weight or less
- the polypropylene resin (Z) particles are foamed by being discharged into a foaming atmosphere having a foaming atmosphere temperature of 90 ° C. or more and 105 ° C. or less.
- Tmh determined from the DSC curve of the polypropylene resin (Z) according to Example 1 is shown in FIG. 1, and Tc is shown in FIG.
- the low temperature side crystal melting peak temperature presumed to be mainly derived from the polyethylene resin (Y), and mainly the polypropylene resin.
- the DSC curve obtained in the above step (i) shows the crystallization peak temperature although the polyethylene resin (Y) is added to the polypropylene resin (X). Tc had only a single peak.
- Expansion ratio (times) of expanded particles d ⁇ v / w.
- Closed cell ratio of expanded particles (%) (1 ⁇ (Va ⁇ Vc) / Va) ⁇ 100
- Vc was measured using Tokyo Science Co., Ltd. air comparison type hydrometer model 1000.
- the volume Va (cm 3 ) was determined by submerging the entire amount of foamed particles after measuring Vc with the above-mentioned air-comparing hydrometer into a graduated cylinder containing ethanol and increasing the liquid level of the graduated cylinder (submerged method) This is the apparent volume of the expanded particles obtained from
- the wrinkle shrinkage rate (%) of the expanded particles 100 ⁇ (1 ⁇ v / v ′).
- In-mold foam molding density The dimensions of the three sides of the long axis, short axis, and thickness of the obtained in-mold foam molded product (cuboid shape) were measured with a caliper and multiplied to calculate the dimensional volume. Based on the dimensional volume and the separately measured weight, the in-mold foam molding density was calculated using the following formula.
- In-mold foam molding density (weight) / (long axis dimension ⁇ short axis dimension ⁇ thickness dimension).
- Compressive strength of in-mold foam molding Four test pieces each having a length of 50 mm, a width of 50 mm, and a thickness of 25 mm were cut out from the obtained in-mold foam molded product, and each was compressed at a speed of 10 mm / min according to NDS-Z0504. Compressive stress (MPa) (hereinafter referred to as “compressive strength”) was measured. The compressive strength of the in-mold foam molding was evaluated according to the following criteria. ⁇ : The compressive strength of all test pieces is equal to or higher than the pass / fail judgment line. X: A test piece having a compressive strength less than a pass / fail judgment line exists.
- FIG. 3 shows the relationship between the density of the in-mold foam molded product and the compressive strength.
- the reference line and the pass / fail judgment line were determined by plotting the compressive strength against the in-mold foam molding density for the in-mold foam molding made of foam particles having an expansion ratio of less than 20 times.
- the foaming ratio is about 12 times, about 14 times.
- the fact that the compressive strength is higher than the pass / fail judgment line means that the compression by increasing the foaming ratio even when the polypropylene resin (Z) is processed into an in-mold foam molded body having a high foaming ratio. This means that an excessive decrease in strength is not observed (the ratio of compressive strength to in-mold foam molding density does not decrease even when compared with in-mold foam moldings with a low expansion ratio).
- the compression strength being less than the pass / fail judgment line means that when the polypropylene resin (Z) is molded into an in-mold foam molded product having a high foaming ratio, excessive compression is caused by increasing the foaming ratio. A decrease in strength has occurred.
- the number Ns (number) of particles broken at the particle interface in the total number of particles N (number) among the expanded particles existing within the 15 mm ⁇ 15 mm area of the fracture surface was counted.
- the fusing property was evaluated according to the following criteria.
- In-mold foam molding fusion rate (%) 100 ⁇ (1 ⁇ Ns / N) ⁇ : The fusion rate is 80% or more. ⁇ : The fusion rate is 60% or more and less than 80%. X: The fusion rate is less than 60%.
- Example 1 [Preparation of polypropylene resin particles]
- Polypropylene resin (X), polyethylene resin (Y), and water-absorbing agent are mixed in the types and amounts shown in Table 1 and kneaded with a 50 mm ⁇ extruder (resin temperature 210 ° C.). After extrusion, granulation was carried out by cutting to produce resin particles (1.2 mg / grain) made of polypropylene resin (Z).
- the dispersion was discharged through a 3 mm ⁇ orifice provided at the lower part of the pressure vessel while being held at the foaming pressure with carbon dioxide gas, and released into a foaming atmosphere maintained in the state shown in Table 1 to obtain single-stage foamed particles.
- Example 9 [Preparation of polypropylene resin particles] After mixing polypropylene resin (X) and polyethylene resin (Y) in the types and amounts shown in Table 1, kneading with a 50 mm ⁇ extruder (resin temperature 210 ° C.), and extruding into a strand form from the tip of the extruder Then, granulation was performed by cutting to produce resin particles (1.2 mg / grain) made of polypropylene resin (Z).
- the dispersion was discharged through a 3 mm ⁇ orifice provided at the lower part of the pressure vessel while being held at the foaming pressure with carbon dioxide gas, and released into a foaming atmosphere maintained in the state shown in Table 1 to obtain single-stage foamed particles.
- PE polyethylene
- CO 2 carbon dioxide
- Bu isobutane
- the dispersion was discharged into a foaming atmosphere maintained in the state shown in Table 2 through a 3 mm ⁇ orifice provided at the lower part of the pressure vessel while being kept at the foaming pressure with carbon dioxide gas to obtain one-stage foamed particles.
- Table 1 shows the results of evaluating the compression strength, fusion property, and surface elongation of the obtained in-mold foam moldings for Examples 1 to 8.
- the polypropylene resin (Z) expanded particles obtained by the production method satisfying the requirements of the present invention are molded in-mold expanded molded articles having good compressive strength, fusion property and surface elongation quality. It shows that it can be provided.
- Table 2 shows the results of evaluating the compression strength, fusion property, and surface elongation of the obtained in-mold foam moldings for Comparative Examples 1 to 7.
- Comparative Example 5 produced a two-stage foamed particle having a high expansion ratio without wrinkle shrinkage by two-stage foaming, and an in-mold foam molded article with good moldability was obtained, but the compression strength was low.
- Comparative Example 6 since a resin having a Tmh exceeding 160 ° C. was used, the moldability in the in-mold foam molding deteriorated, and a good in-mold foam molded article could not be obtained. Specifically, mutual fusion between the expanded particles did not occur, and the shape could not be maintained after heating.
- the polypropylene-based resin expanded particles produced by the method according to an embodiment of the present invention is a raw material for a lightweight and high-strength in-mold expanded molded body.
- the in-mold foam molded product can be applied to, for example, the automobile industry.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
Description
DSC6200型(セイコーインスツルメンツ(株)製)を用いた分析法により、樹脂4mg以上6mg以下を10℃/minの昇温速度で40℃から220℃まで昇温して融解させた後、以下の工程で測定を実施した。
嵩体積約50cm3の発泡粒子の重量w(g)およびエタノール水没体積v(cm3)を求め、発泡前の樹脂粒子の密度d=0.9(g/cm3)から次式により発泡粒子の発泡倍率を求めた。
ASTM D2856-87の手順C(PROSEDURE C)に記載の方法に従って得られる発泡粒子の体積をVc(cm3)とし、下記式に従って独立気泡率(%)を求めた。
なお、Vcは、東京サイエンス株式会社製空気比較式比重計モデル1000を用いて測定した。また、体積Va(cm3)は、前記空気比較式比重計にてVcを測定した後の発泡粒子の全量をエタノールの入ったメスシリンダー内に沈め、メスシリンダーの液面上昇分(水没法)から求めた、発泡粒子の見かけ上の体積である。
嵩体積約100cm3の発泡粒子のエタノール水没体積v(cm3)を求めた。次に、該発泡粒子をすべて回収して常温で乾燥し、完全にエタノールを揮発させた。その後、密閉式の耐圧容器内に入れ、0.1MPa/60min以下の速度で容器内圧力0.30MPa(ゲージ圧)まで加圧して0.20MPa(絶対圧)の内圧を付与した該発泡粒子を耐圧容器から取り出し、エタノール水没体積v´を同様に測定し、次式により皺収縮率を算出した。
得られた型内発泡成形体(直方体形状)の長軸、短軸、厚みの3辺の寸法をノギスで測定し、これを乗じて寸法体積を計算した。前記寸法体積および別途測定した重量により、以下の式を用いて、型内発泡成形体密度を算出した。
得られた型内発泡成形体から、縦50mm×横50mm×厚み25mmの各4つのテストピースを切り出し、NDS-Z0504に準拠し、それぞれ10mm/分の速度で圧縮した際の50%圧縮時の圧縮応力(MPa)(以下、「圧縮強度」と称す。)を測定した。型内発泡成形体の圧縮強度については以下の基準により評価した。
○:すべてのテストピースの圧縮強度が合否判定線以上である。
×:圧縮強度が合否判定線未満のテストピースが存在する。
加熱圧0.32MPa(ゲージ圧)での型内発泡成形によって得られる縦400mm×横300mm×厚み50mmの型内発泡成形体の、1つの頂点から縦軸方向に100mmの点Aと、前記頂点から横軸方向に100mmの点Bとを結んだライン上に、アートナイフで深さ10mm程度の切り込みを入れて割り、その破断面の観察を行った。破断面の15mm×15mmの面積内に存在する発泡粒子のうち、全粒子数N(個)に占める粒子界面で割れた粒子の数Ns(個)を計数した。融着性は以下の基準により評価した。
○:融着率が80%以上
△:融着率が60%以上、80%未満
×:融着率が60%未満。
加熱圧0.32MPa(ゲージ圧)での型内発泡成形により得られた型内発泡成形体において、該型内発泡成形体表面の50mm×50mmの面積内に含まれる粒間数を計数した。表面伸びは、以下の基準により評価した。
○:1mm2以上の粒間数が5個未満
△:1mm2以上の粒間数が5個以上、10個未満
×:1mm2以上の粒間数が10個以上。
(1)ポリプロピレン系樹脂(X)
・ポリプロピレン系樹脂A
R3410(LG)
融点148℃、曲げ弾性率 1498MPa、MI=7.1g/min
・ポリプロピレン系樹脂B
F227A(プライムポリマー)
融点143℃、曲げ弾性率 1250MPa、MI=6.2g/min
・ポリプロピレン系樹脂C
E228(プライムポリマー)
融点146℃、曲げ弾性率 1300MPa、MI=8.0g/min
・ポリプロピレン系樹脂D
J106G(プライムポリマー)
融点162℃、曲げ弾性率 1600MPa、MI=15.0g/min。
・ポリエチレン系樹脂A
HI-ZEX 2200J(プライムポリマー)
密度0.964g/cm3、融点135℃
・ポリエチレン系樹脂B
NEO-ZEX 2540R(プライムポリマー)
密度0.923g/cm3、融点121℃。
・グリセリン(花王ケミカルズ):精製グリセリン
・ポリエチレングリコール(ライオン株式会社):PEG#300。
[ポリプロピレン系樹脂粒子の作製]
ポリプロピレン系樹脂(X)、ポリエチレン系樹脂(Y)、吸水剤を表1に示す種類および量にて混合し、50mmφの押出機で混練(樹脂温度210℃)し、押出機先端からストランド状に押出した後、カッティングすることにより造粒し、ポリプロピレン系樹脂(Z)からなる樹脂粒子(1.2mg/粒)を製造した。
10L耐圧容器に、水300重量部、得られたポリプロピレン系樹脂(Z)粒子100重量部、分散剤として第三リン酸カルシウム1.0重量部、分散助剤としてノルマルパラフィンスルホン酸ソーダ0.5重量部、および発泡剤として炭酸ガスを6.0重量部仕込み、撹拌下、昇温し、表1に示す発泡温度(容器内温度)および発泡圧力(容器内圧力)で30分間保持した。その後、炭酸ガスで前記発泡圧力に保持しながら耐圧容器の下部に設けた3mmφオリフィスを通して分散液を、表1に示す状態に保持した発泡雰囲気下に放出し、一段発泡粒子を得た。
次に、得られた一段発泡粒子に0.2MPa(絶対圧)の内圧を付与し、長軸400mm×短軸300mm×厚み50mmの直方体状金型に充填し、水蒸気(0.32MPa(ゲージ圧))にて12秒加熱、融着させ、型内発泡成形体を得、金型から取り出した。金型から取り出した型内発泡成形体を75℃の乾燥器中で24時間乾燥、養生した後、型内発泡成形体の品質を確認した。結果を、表1に示す。
[ポリプロピレン系樹脂粒子の作製]
ポリプロピレン系樹脂(X)、ポリエチレン系樹脂(Y)を表1に示す種類および量にて混合し、50mmφの押出機で混練(樹脂温度210℃)し、押出機先端からストランド状に押出した後、カッティングすることにより造粒し、ポリプロピレン系樹脂(Z)からなる樹脂粒子(1.2mg/粒)を製造した。
10L耐圧容器に、水300重量部、得られたポリプロピレン系樹脂(Z)粒子100重量部、分散剤として第三リン酸カルシウム1.5重量部、分散助剤としてノルマルパラフィンスルホン酸ソーダ0.05重量部、および発泡剤としてイソブタンを10.0重量部仕込み、撹拌下、昇温し、表1に示す発泡温度(容器内温度)および発泡圧力(容器内圧力)で30分間保持した。その後、炭酸ガスで前記発泡圧力に保持しながら耐圧容器の下部に設けた3mmφオリフィスを通して分散液を、表1に示す状態に保持した発泡雰囲気下に放出し、一段発泡粒子を得た。
次に、得られた一段発泡粒子に0.2MPa(絶対圧)の内圧を付与し、長軸400mm×短軸300mm×厚み50mmの直方体状金型に充填し、水蒸気(0.32MPa(ゲージ圧))にて12秒加熱、融着させ、型内発泡成形体を得、金型から取り出した。金型から取り出した型内発泡成形体を75℃の乾燥器中で24時間乾燥、養生した後、型内発泡成形体の品質を確認した。結果を、表1に示す。
[ポリプロピレン系樹脂粒子の作製]
ポリプロピレン系樹脂(X)、ポリエチレン系樹脂(Y)、吸水剤を表2に示す種類および量にて混合し、50mmφの押出機で混練(樹脂温度210℃)し、押出機先端からストランド状に押出した後、カッティングすることにより造粒し、ポリプロピレン系樹脂(Z)からなる樹脂粒子(1.2mg/粒)を製造した。
10L耐圧容器に、水300重量部、得られたポリプロピレン系樹脂(Z)粒子100重量部、分散剤として第三リン酸カルシウム1.0重量部、分散助剤としてノルマルパラフィンスルホン酸ソーダ0.5重量部、および発泡剤として炭酸ガスを6.0重量部仕込み、撹拌下、昇温し、表2に示す発泡温度(容器内温度)および発泡圧力(容器内圧力)で30分間保持した。その後、炭酸ガスで前記発泡圧力に保持しながら耐圧容器の下部に設けた3mmφオリフィスを通して分散液を、表2に示す状態に保持した発泡雰囲気下に放出し、一段発泡粒子を得た。
次に、得られた一段発泡粒子に0.2MPa(絶対圧)の内圧を付与し、長軸400mm×短軸300mm×厚み50mmの直方体状金型に充填し、水蒸気(0.32MPa(ゲージ圧))にて12秒加熱、融着させ、型内発泡成形体を得、金型から取り出した。
金型から取り出した型内発泡成形体を75℃の乾燥器中で24時間乾燥、養生した後、型内発泡成形体の品質を確認した。結果を、表2に示す。なお、表中「PE」はポリエチレン、「CO2」は炭酸ガスを表す。
Claims (12)
- ポリプロピレン系樹脂(X)100重量部に対し、密度0.945g/cm3以上0.980g/cm3未満のポリエチレン系樹脂(Y)を1重量部以上10重量部以下混合して得られる、146℃以上160℃以下の高温側結晶融解ピーク温度を有するポリプロピレン系樹脂(Z)粒子を、耐圧容器内で水系分散媒に分散させ、該耐圧容器内に発泡剤を導入し、加熱、加圧条件下でポリプロピレン系樹脂(Z)粒子に発泡剤を含浸させる工程と、
前記ポリプロピレン系樹脂(Z)粒子を前記耐圧容器の内圧よりも低い圧力領域へ放出することにより、前記ポリプロピレン系樹脂(Z)粒子を発泡させてポリプロピレン系樹脂(Z)発泡粒子を得る工程と、を含み、
前記ポリプロピレン系樹脂(Z)発泡粒子は、発泡倍率が20倍以上40倍以下、独立気泡が90%以上、且つ皺収縮率が5%以下であり、
前記ポリプロピレン系樹脂(Z)発泡粒子を、1回の発泡工程で製造することを特徴とする、ポリプロピレン系樹脂(Z)発泡粒子の製造方法。 - 炭酸ガスを含む発泡剤を用いることを特徴とする請求項1記載のポリプロピレン系樹脂(Z)発泡粒子の製造方法。
- 前記ポリプロピレン系樹脂(Z)粒子を、90℃以上、105℃以下の発泡雰囲気温度とした発泡雰囲気へ放出することにより発泡させることを特徴とする、請求項1または2に記載のポリプロピレン系樹脂(Z)発泡粒子の製造方法。
- 前記ポリプロピレン系樹脂(Z)がポリプロピレン系樹脂(X)よりも高い結晶化温度を有する請求項1~3のいずれか一項に記載のポリプロピレン系樹脂(Z)発泡粒子の製造方法。
- 前記ポリプロピレン系樹脂(Z)粒子が、吸水剤を含有することを特徴とする、請求項1~4のいずれか一項に記載のポリプロピレン系樹脂(Z)発泡粒子の製造方法。
- 前記吸水剤がポリエチレングリコールおよび/またはグリセリンである、請求項5に記載のポリプロピレン系樹脂(Z)発泡粒子の製造方法。
- 前記吸水剤の含有量が、ポリプロピレン系樹脂(X)100重量部に対して、0.01重量部以上10重量部以下である、請求項5または6に記載のポリプロピレン系樹脂(Z)発泡粒子の製造方法。
- 請求項1~7のいずれか一項に記載のポリプロピレン系樹脂(Z)発泡粒子の製造方法により製造されるポリプロピレン系樹脂(Z)発泡粒子。
- 請求項8記載のポリプロピレン系樹脂(Z)発泡粒子を用いた型内発泡成形体。
- 請求項9に記載の型内発泡成形体であって、型内発泡成形体密度が15g/L以上30g/L以下であることを特徴とする型内発泡成形体。
- 型内発泡成形体密度および圧縮強度を測定し、前記型内発泡成形体密度を横軸、前記圧縮強度を縦軸とする座標平面上にプロットしたとき、下記(1)~(3)の手順によって決定される合否判定線以上にプロットされる、型内発泡成形体。
(1)ポリプロピレン系樹脂(X)100重量部に対し、密度0.945g/cm3以上0.980g/cm3未満のポリエチレン系樹脂(Y)を1重量部以上10重量部以下混合して得られる、146℃以上160℃以下の高温側結晶融解ピーク温度を有するポリプロピレン系樹脂(Z)を基材樹脂とし、発泡倍率が10倍以上20倍未満であるポリプロピレン系樹脂(Z)発泡粒子からなる型内発泡成形体のサンプルを用意する。
(2)該サンプルの型内発泡成形体密度および圧縮強度を計測した値を、前記座標平面上に2点以上プロットする。
(3)(2)においてプロットされた点に基づき、前記座標平面の原点を通る一次近似線を基準線とし、該基準線に対して圧縮強度が3.0%低い線を合否判定線とする。 - 型内発泡成形体密度が15g/L以上30g/L以下であることを特徴とする、請求項11記載の型内発泡成形体。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2017552347A JP6670850B2 (ja) | 2015-11-26 | 2016-11-09 | ポリプロピレン系樹脂発泡粒子の製造方法、ポリプロピレン系樹脂発泡粒子および型内発泡成形体 |
EP16868380.3A EP3381976B1 (en) | 2015-11-26 | 2016-11-09 | Method for producing polypropylene-based resin foamed particles, polypropylene-based resin foamed particles, and in-mold foam molded article |
CN201680069241.9A CN108291048B (zh) | 2015-11-26 | 2016-11-09 | 聚丙烯系树脂发泡颗粒的制造方法、聚丙烯系树脂发泡颗粒及模内发泡成型体 |
US15/989,528 US20180273719A1 (en) | 2015-11-26 | 2018-05-25 | Method for producing polypropylene-based resin foamed particles, polypropylene-based resin foamed particles, and in-mold foam molded article |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015230292 | 2015-11-26 | ||
JP2015-230292 | 2015-11-26 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/989,528 Continuation US20180273719A1 (en) | 2015-11-26 | 2018-05-25 | Method for producing polypropylene-based resin foamed particles, polypropylene-based resin foamed particles, and in-mold foam molded article |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017090432A1 true WO2017090432A1 (ja) | 2017-06-01 |
Family
ID=58763224
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2016/083280 WO2017090432A1 (ja) | 2015-11-26 | 2016-11-09 | ポリプロピレン系樹脂発泡粒子の製造方法、ポリプロピレン系樹脂発泡粒子および型内発泡成形体 |
Country Status (5)
Country | Link |
---|---|
US (1) | US20180273719A1 (ja) |
EP (1) | EP3381976B1 (ja) |
JP (1) | JP6670850B2 (ja) |
CN (1) | CN108291048B (ja) |
WO (1) | WO2017090432A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2019172204A1 (ja) * | 2018-03-08 | 2019-09-12 | 株式会社カネカ | ポリプロピレン系樹脂発泡粒子およびその製造方法 |
WO2023176805A1 (ja) * | 2022-03-15 | 2023-09-21 | 株式会社カネカ | ポリプロピレン系発泡粒子およびポリプロピレン系発泡粒子の製造方法 |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008255286A (ja) * | 2007-04-09 | 2008-10-23 | Kaneka Corp | 黒色のポリプロピレン系樹脂予備発泡粒子 |
WO2009047998A1 (ja) * | 2007-10-11 | 2009-04-16 | Kaneka Corporation | ポリプロピレン系樹脂予備発泡粒子及びその製造方法 |
US20090176902A1 (en) * | 2006-08-25 | 2009-07-09 | Manfred Stadlbauer | Polypropylene foam |
JP2010265449A (ja) * | 2009-04-14 | 2010-11-25 | Tosoh Corp | プロピレン重合体樹脂組成物 |
EP2508555A1 (en) * | 2011-03-21 | 2012-10-10 | Electrolux Home Products Corporation N.V. | Process for producing pre-expandable plastic beads and beads obtainable according to said process |
WO2014136933A1 (ja) * | 2013-03-08 | 2014-09-12 | 株式会社カネカ | ポリプロピレン系樹脂発泡粒子の製造方法 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2754687B1 (en) * | 2007-12-11 | 2018-08-22 | Kaneka Corporation | Process for producing expanded polyolefin resin particles and expanded polyolefin resin particles |
JP2010275499A (ja) * | 2009-06-01 | 2010-12-09 | Tosoh Corp | ポリプロピレン系樹脂組成物からなる予備発泡粒子、その製造方法及び型内発泡成形体 |
CN105849167B (zh) * | 2013-12-27 | 2020-04-14 | 株式会社钟化 | 聚烯烃系树脂发泡粒子及聚烯烃系树脂模内发泡成型体 |
EP3339358B1 (en) * | 2015-08-20 | 2020-12-02 | Kaneka Corporation | Polypropylene resin foamed particles, method for producing polypropylene resin foamed particles and polypropylene resin in-mold foam-molded article |
-
2016
- 2016-11-09 CN CN201680069241.9A patent/CN108291048B/zh active Active
- 2016-11-09 WO PCT/JP2016/083280 patent/WO2017090432A1/ja active Application Filing
- 2016-11-09 JP JP2017552347A patent/JP6670850B2/ja active Active
- 2016-11-09 EP EP16868380.3A patent/EP3381976B1/en active Active
-
2018
- 2018-05-25 US US15/989,528 patent/US20180273719A1/en not_active Abandoned
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090176902A1 (en) * | 2006-08-25 | 2009-07-09 | Manfred Stadlbauer | Polypropylene foam |
JP2008255286A (ja) * | 2007-04-09 | 2008-10-23 | Kaneka Corp | 黒色のポリプロピレン系樹脂予備発泡粒子 |
WO2009047998A1 (ja) * | 2007-10-11 | 2009-04-16 | Kaneka Corporation | ポリプロピレン系樹脂予備発泡粒子及びその製造方法 |
JP2010265449A (ja) * | 2009-04-14 | 2010-11-25 | Tosoh Corp | プロピレン重合体樹脂組成物 |
EP2508555A1 (en) * | 2011-03-21 | 2012-10-10 | Electrolux Home Products Corporation N.V. | Process for producing pre-expandable plastic beads and beads obtainable according to said process |
WO2014136933A1 (ja) * | 2013-03-08 | 2014-09-12 | 株式会社カネカ | ポリプロピレン系樹脂発泡粒子の製造方法 |
Non-Patent Citations (1)
Title |
---|
See also references of EP3381976A4 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2019172204A1 (ja) * | 2018-03-08 | 2019-09-12 | 株式会社カネカ | ポリプロピレン系樹脂発泡粒子およびその製造方法 |
JPWO2019172204A1 (ja) * | 2018-03-08 | 2021-02-18 | 株式会社カネカ | ポリプロピレン系樹脂発泡粒子およびその製造方法 |
JP7269220B2 (ja) | 2018-03-08 | 2023-05-08 | 株式会社カネカ | ポリプロピレン系樹脂発泡粒子およびその製造方法 |
WO2023176805A1 (ja) * | 2022-03-15 | 2023-09-21 | 株式会社カネカ | ポリプロピレン系発泡粒子およびポリプロピレン系発泡粒子の製造方法 |
Also Published As
Publication number | Publication date |
---|---|
EP3381976A4 (en) | 2019-04-24 |
EP3381976A1 (en) | 2018-10-03 |
CN108291048B (zh) | 2021-07-06 |
CN108291048A (zh) | 2018-07-17 |
JPWO2017090432A1 (ja) | 2018-08-23 |
EP3381976B1 (en) | 2022-01-26 |
US20180273719A1 (en) | 2018-09-27 |
JP6670850B2 (ja) | 2020-03-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5375613B2 (ja) | ポリプロピレン系樹脂予備発泡粒子及びその製造方法 | |
WO2011086937A1 (ja) | ポリエチレン系樹脂発泡粒子、およびポリエチレン系樹脂型内発泡成形体 | |
JP5976098B2 (ja) | ポリプロピレン系樹脂発泡粒子およびポリプロピレン系樹脂発泡粒子からなる型内発泡成形体、並びに、これらの製造方法 | |
WO2016111017A1 (ja) | プロピレン系樹脂発泡粒子及び発泡粒子成形体 | |
WO2015076306A1 (ja) | ポリエチレン系樹脂発泡粒子およびポリエチレン系樹脂型内発泡成形体およびその製造方法 | |
JP5188144B2 (ja) | 摩擦音のしないポリプロピレン系樹脂予備発泡粒子 | |
JP5630591B2 (ja) | ポリオレフィン系樹脂予備発泡粒子およびその製造方法 | |
JP5242321B2 (ja) | 摩擦音の低減されたポリプロピレン系樹脂予備発泡粒子 | |
JP6084046B2 (ja) | ポリエチレン系樹脂発泡粒子およびポリエチレン系樹脂型内発泡成形体およびその製造方法 | |
WO2013031745A1 (ja) | ポリエチレン系樹脂発泡粒子及びその成形体 | |
JP6670850B2 (ja) | ポリプロピレン系樹脂発泡粒子の製造方法、ポリプロピレン系樹脂発泡粒子および型内発泡成形体 | |
JP5591965B2 (ja) | ポリオレフィン系樹脂予備発泡粒子およびその製造方法 | |
WO2016158686A1 (ja) | ポリエチレン系樹脂発泡成形体の製造方法 | |
JP5475149B2 (ja) | 摩擦音のしないポリプロピレン系樹脂予備発泡粒子 | |
JP5347368B2 (ja) | ポリプロピレン系樹脂発泡粒子、および型内発泡成形体 | |
JP4940688B2 (ja) | ポリプロピレン系樹脂予備発泡粒子の製造方法 | |
WO2016147775A1 (ja) | 帯電防止性能を有するポリエチレン系樹脂発泡粒子およびポリエチレン系樹脂型内発泡成形体およびその製造方法 | |
JP5315759B2 (ja) | ポリプロピレン系樹脂型内発泡成形体の製造方法 | |
JP5216353B2 (ja) | ポリプロピレン系樹脂発泡粒子の製造方法 | |
JP2013181074A (ja) | スチレン改質ポリエチレン系樹脂粒子、発泡性複合樹脂粒子、予備発泡粒子、発泡成形体及び予備発泡粒子の製造方法 | |
JP2017179281A (ja) | ポリプロピレン系樹脂発泡粒子、および、ポリプロピレン系樹脂型内発泡成形体、およびその製造方法 | |
JP5460227B2 (ja) | ポリプロピレン系樹脂型内発泡成形体 | |
JP2009221258A (ja) | ポリプロピレン系樹脂予備発泡粒子 | |
JP2009256410A (ja) | ポリプロピレン系樹脂発泡粒子の製造方法 | |
JP5161593B2 (ja) | ポリプロピレン系樹脂発泡粒子の製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 16868380 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2017552347 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2016868380 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2016868380 Country of ref document: EP Effective date: 20180626 |