JP6817514B2 - Polypropylene resin foam molded product and its manufacturing method - Google Patents

Description

The present invention relates to a polypropylene-based resin foam molded article having excellent mechanical strength and a method for producing the same. Specifically, the present invention is made of polypropylene having improved mechanical strength by containing a specific amide compound, particularly fine acicular crystals thereof. Regarding a resin foam molded product.

Conventionally, polypropylene-based resin foam molded products have the excellent heat resistance, mechanical properties, and workability of polypropylene-based resins themselves, as well as the lightness and heat insulating properties that are the characteristics of foamed molded products. As an environment-friendly material that is resource-saving and has excellent recyclability, it is widely used in fields that require impact resistance and heat insulation, such as automobiles, electrical and electronic parts, and building materials. It is expected that the fields of application will increase more and more in the future as cushioning materials, packaging materials, packing materials, etc.

Further, in recent years, in order to save resources and reduce weight, a foam molded product having a higher foaming ratio has been desired, and the same applies to a polypropylene-based resin foamed molded product. However, since polypropylene-based resins have low viscosity and tension at the time of melting, it is difficult to produce a foam molded product having a high foaming ratio, and improvement thereof is necessary, and various improvements have been attempted so far. For example, there are disclosed pre-foamed particles of polypropylene-based resin for producing a foamed molded article, which are characterized in that polypropylene-based resin particles contain a volatile foaming agent and are pre-foamed by heating (Patent Document 1). .. Further, as a technique for manufacturing a polypropylene-based resin foam molded product, a technique for branching polypropylene by radiation (Patent Document 2) and a technique for manufacturing branched polypropylene using a peroxide (Patent Document 3) are disclosed. There is.

However, when the foamed particles are used, there is a problem that the mechanical strength tends to decrease due to insufficient adhesiveness between the foamed particles. As an improvement method, a method for producing prefoamed particles using a β-crystal nucleating agent is disclosed (Patent Document 4), but the current situation is that satisfactory mechanical strength has not yet been obtained. In addition, when radiation or peroxide is used, the recyclability is poor, which is a big problem for general-purpose use, and it is difficult to use it practically.

Japanese Unexamined Patent Publication No. 58-65734 Japanese Unexamined Patent Publication No. 62-121704 Japanese Unexamined Patent Publication No. 2-298536 Japanese Unexamined Patent Publication No. 8-67760

An object of the present invention is to make use of the excellent heat resistance and mechanical properties originally possessed by a polypropylene resin to further increase the foaming ratio, that is, a polypropylene resin having a high foaming ratio having excellent mechanical strength. The present invention provides a foam molded product and a method for producing the same.

In view of the above situation, the present inventors have diligently studied to achieve the above problems, and as a result, prepared a polypropylene-based resin composition containing a specific amide compound, particularly its fine acicular crystals, under specific molding conditions. After that, the polypropylene-based resin composition for foam molding is heated, and then a foaming agent, particularly carbon dioxide, is added as a foaming agent, and then foaming is performed so that the foamed molded product can achieve the above-mentioned problems. Was found, and the present invention was completed based on this.

That is, the present invention provides the following polypropylene-based resin foam molded article, a method for producing the same, and a polypropylene-based resin composition for producing the polypropylene-based resin foam molded article.

[Item 1] A polypropylene-based resin containing at least one amide compound selected from the group consisting of the amide compound represented by the following general formula (1) and the amide compound represented by the general formula (2). Foam molded product.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, 6 to alicyclic amine residue or carbon atoms of 5 to 30 carbon atoms Represents 30 aromatic amine residues. ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ]

[Item 2] The polypropylene-based resin foam molded product according to [Item 1], wherein the amide compound is a fine acicular crystal.

[Item 3] The polypropylene-based resin foam molded product according to [Item 1] or [Item 2], wherein the amide compound is at least one amide compound represented by the following general formula (3).
[In formula (3), R ⁷ is a saturated or unsaturated aliphatic dicarboxylic acid residue having 2 to 18 carbon atoms, a saturated or unsaturated aliphatic dicarboxylic acid residue having 3 to 18 carbon atoms, or a carbon. Representing aromatic dicarboxylic acid residues of numbers 6 to 18, R ⁸ and R ⁹ are the same or different cycloalkyl groups having 5 to 18 carbon atoms, respectively, the following general formulas (a) and (b). , Represents a group represented by the general formula (c) or the general formula (d)
[In formulas (a) to (d), R ¹⁰ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 6 to 10 carbon atoms, or a phenyl group, and R ¹¹ represents a linear or branched alkyl group having 1 to ¹² carbon atoms, R ¹² represents a linear or branched alkylene group having 1 to 4 carbon atoms, and R ¹³ represents a linear or branched alkylene group having 1 to 4 carbon atoms. Represents 1 to 4 linear or branched alkylene groups). ]

[Item 4] In the general formula (3), R ⁷ is a saturated or unsaturated aliphatic dicarboxylic acid residue having 3 to 12 carbon atoms and a saturated or unsaturated aliphatic dicarboxylic acid residue having 6 to 10 carbon atoms. , Or an aromatic dicarboxylic acid residue having 6 to 18 carbon atoms, and R ⁸ and R ⁹ are the same or different, cycloalkyl groups having 5 to 12 carbon atoms, respectively, or general formulas (a) and general formulas (a). b), The polypropylene-based resin foam molded product according to [Item 3], which represents a group represented by the general formula (c) or the general formula (d).

[Item 5] In the general formula (3), R ⁷ is a saturated aliphatic dicarboxylic acid residue having 4 to 8 carbon atoms, a saturated alicyclic dicarboxylic acid residue having 6 to 8 carbon atoms, or 6 to 6 carbon atoms. Eighteen aromatic dicarboxylic acid residues, R ⁸ and R ^{9 each} having the same or different number of cyclohexyl groups or one carbon number which may be substituted with one alkyl group having 1 to 4 carbon atoms. Item 4. The polypropylene-based resin foam molded product according to [Item 4], which is a phenyl group that may be substituted with 1 to 4 alkyl groups.

[Item 6] In the general formula (3), R ⁷ is an aromatic dicarboxylic acid residue represented by the following general formula (e), and R ⁸ and R ⁹ are the same or different, and one each. Item 5. The polypropylene-based resin foam molded article according to [Item 5], which is a cyclohexyl group that may be substituted with an alkyl group having 1 to 4 carbon atoms.

[Item 7] The polypropylene-based resin foam molded product according to [Item 6], wherein the amide compound is 2,6-naphthalenedicarboxylic acid dicyclohexylamide.

[Item 8] The polypropylene-based resin foam molded product according to [Item 1] or [Item 2], wherein the amide compound is at least one amide compound represented by the following general formula (4).
[In the formula, R ¹⁴ is a saturated or unsaturated aliphatic tricarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic tricarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic tricarboxylic acid having 6 to 18 carbon atoms. Represents a residue. Three ^{R 15} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, having 5 to 30 carbon atoms alicyclic amine residue or C6-30 Represents an aromatic amine residue. ]

[Item 9] The polypropylene-based resin foam molded product according to [Item 8], wherein the amide compound is at least one amide compound represented by the following general formula (5).
[In the formula, R ¹⁶ , R ¹⁷ , and R ¹⁸ are the same or different, and are represented by the following general formula (f), which are linear or branched alkyl or alkenyl groups or phenyl groups having 5 to 20 carbon atoms. It represents a cycloalkyl group to be used, or an alkyl-substituted cycloalkyl group represented by the following general formula (g). ]
[In the formula, x represents an integer of 1-8. ]
[In the formula, R ¹⁹ represents a linear or branched chain alkyl group having 1 to 4 carbon atoms. y represents an integer of 1-8. z represents an integer of 1 to 4. When z is 2 or more, each R ¹⁹ may be the same or different from each other. ]

[Item 10] The polypropylene according to any one of [Item 1] to [Item 9], wherein the content of the amide compound is in the range of 0.001 to 10 parts by weight with respect to 100 parts by weight of the polypropylene resin. Based resin foam molded product.

[Item 11] The polypropylene-based resin foam molded article according to [Item 10], wherein the content of the amide compound is in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the polypropylene-based resin.

[Item 12] The polypropylene resin foam molding according to any one of [Item 1] to [Item 11], wherein the melt flow rate of the polypropylene resin at 230 ° C. and a load of 2160 g is 0.1 to 60.0 g / 10 minutes. body.

[Item 13] The polypropylene-based resin foam molded article according to [Item 12], wherein the melt flow rate of the polypropylene-based resin at 230 ° C. and a load of 2160 g is 0.2 to 40.0 g / 10 minutes.

[Item 14] (i) 240 to at least one amide compound selected from the group consisting of a polypropylene-based resin, an amide compound represented by the following general formula (1), and an amide compound represented by the general formula (2). A step of heating to a temperature range of 330 ° C., melting and mixing, and dissolving the amide compound in the melted polypropylene resin.
(Ii) A step of cooling the molten polypropylene-based resin composition obtained in step (i) to a temperature of 80 ° C. or lower and precipitating fine acicular crystals of an amide compound in the solidified polypropylene-based resin composition.
(Iii) The polypropylene-based resin composition obtained in step (ii) is characterized by comprising a foam molding step of mixing a foaming agent, heating and mixing in a temperature range of 190 to 260 ° C., and then foaming. A method for producing a polypropylene-based resin foam molded article.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, 6 to alicyclic amine residue or carbon atoms of 5 to 30 carbon atoms Represents 30 aromatic amine residues. ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ]

[Item 15] The production method according to [Item 14], wherein the foaming agent is an inorganic or organic chemical foaming agent.

[Item 16] (i) A polypropylene resin is melt-mixed with at least one amide compound selected from the group consisting of the amide compound represented by the following general formula (1) and the amide compound represented by the general formula (2). After that, the process of cooling and solidifying to produce a polypropylene-based resin composition containing an amide compound,
(Ii) The polypropylene-based resin composition obtained in step (i) is heated to a temperature range of 240 to 330 ° C. to dissolve the amide compound in the molten polypropylene-based resin, and then to a temperature of 80 ° C. or lower. A step of cooling and molding a molded product having a predetermined shape containing fine needle-like crystals of an amide compound uniformly.
(Iii) A polypropylene-based product comprising a foam molding step of heating the molded product obtained in step (ii) to a temperature range of 150 to 240 ° C., injecting a foaming agent, and then foaming. A method for manufacturing a resin foam molded product.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, 6 to alicyclic amine residue or carbon atoms of 5 to 30 carbon atoms Represents 30 aromatic amine residues. ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ]

[Item 17] (i) A polypropylene-based resin is melt-mixed with at least one amide compound selected from the group consisting of an amide compound represented by the following general formula (1) and an amide compound represented by the general formula (2). After that, the polypropylene-based resin composition obtained in the steps (ii) and (i) of producing a polypropylene-based resin composition containing an amide compound by cooling and solidifying is heated to a temperature range of 240 to 330 ° C. After dissolving the amide compound in the molten polypropylene resin, cool it at the same temperature or to a temperature range of 220 to 280 ° C, inject a foaming agent, and further lower the temperature to a temperature range of 150 to 220 ° C. A method for producing a polypropylene-based resin foam molded product, which comprises a foam molding step for subsequent foaming.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, 6 to alicyclic amine residue or carbon atoms of 5 to 30 carbon atoms Represents 30 aromatic amine residues. ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ]

[Item 18] The production method according to [Item 16] or [Item 17], wherein the foaming agent is an inert gas in a supercritical state.

[Item 19] The production method according to [Item 18], wherein the inert gas is carbon dioxide.

[Item 20] The production method according to any one of [Item 14] to [Item 19], wherein the foaming ratio in the foam molding step is 1.2 to 100 times.

[Item 21] A polypropylene-based resin containing at least one amide compound selected from the group consisting of the amide compound represented by the following general formula (1) and the amide compound represented by the general formula (2). A polypropylene-based resin composition for producing a foamed molded product.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, 6 to alicyclic amine residue or carbon atoms of 5 to 30 carbon atoms Represents 30 aromatic amine residues. ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ]

[Item 22] The polypropylene-based resin composition for producing a polypropylene-based resin foam molded article according to [Item 21], wherein the amide compound is a fine acicular crystal.

[Item 23] The polypropylene-based resin according to [Item 21] or [Item 22], wherein the amide compound is at least one amide compound represented by the following general formula (3). Composition.
[In formula (3), R ⁷ is a saturated or unsaturated aliphatic dicarboxylic acid residue having 2 to 18 carbon atoms, a saturated or unsaturated aliphatic dicarboxylic acid residue having 3 to 18 carbon atoms, or a carbon. Representing aromatic dicarboxylic acid residues of numbers 6 to 18, R ⁸ and R ⁹ are the same or different cycloalkyl groups having 5 to 18 carbon atoms, respectively, the following general formulas (a) and (b). , Represents a group represented by the general formula (c) or the general formula (d)
(In formulas (a) to (d), R ¹⁰ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 6 to 10 carbon atoms, or a phenyl group, and R ¹¹ represents a linear or branched alkyl group having 1 to ¹² carbon atoms, R ¹² represents a linear or branched alkylene group having 1 to 4 carbon atoms, and R ¹³ represents a linear or branched alkylene group having 1 to 4 carbon atoms. Represents 1 to 4 linear or branched alkylene groups). ]

[Item 24] In the general formula (3), R ⁷ is a saturated or unsaturated aliphatic dicarboxylic acid residue having 3 to 12 carbon atoms and a saturated or unsaturated aliphatic dicarboxylic acid residue having 6 to 10 carbon atoms. , Or an aromatic dicarboxylic acid residue having 6 to 18 carbon atoms, and R ⁸ and R ⁹ are the same or different, cycloalkyl groups having 5 to 12 carbon atoms, respectively, or general formulas (a) and general formulas (a). b), The polypropylene-based resin composition for producing a polypropylene-based resin foam molded product according to [Item 23], which represents a group represented by the general formula (c) or the general formula (d).

[Item 25] In the general formula (3), R ⁷ is a saturated aliphatic dicarboxylic acid residue having 4 to 8 carbon atoms, a saturated alicyclic dicarboxylic acid residue having 6 to 8 carbon atoms, or 6 to 6 carbon atoms. Eighteen aromatic dicarboxylic acid residues, R ⁸ and R ^{9 each} having the same or different number of cyclohexyl groups or one carbon number which may be substituted with one alkyl group having 1 to 4 carbon atoms. The polypropylene-based resin composition for producing a polypropylene-based resin foam molded product according to [Item 24], which is a phenyl group which may be substituted with 1 to 4 alkyl groups.

[Item 26] In the general formula (3), R ⁷ is the general formula (e).
It is an aromatic dicarboxylic acid residue represented by, and R ⁸ and R ⁹ are cyclohexyl groups which are the same or different and may be substituted with one alkyl group having 1 to 4 carbon atoms, respectively. 25] The polypropylene-based resin composition for producing a polypropylene-based resin foam molded body according to the above.

[Item 27] The polypropylene-based resin composition for producing a polypropylene-based resin foam molded product according to [Item 26], wherein the amide compound is 2,6-naphthalenedicarboxylic acid dicyclohexylamide.

[Item 28] The polypropylene-based resin according to [Item 21] or [Item 22], wherein the amide compound is at least one amide compound represented by the following general formula (4). Composition.
[In the formula, R ¹⁴ is a saturated or unsaturated aliphatic tricarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic tricarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic tricarboxylic acid having 6 to 18 carbon atoms. Represents a residue. Three ^{R 15} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, having 5 to 30 carbon atoms alicyclic amine residue or C6-30 Represents an aromatic amine residue. ]

[Item 29] The polypropylene-based resin composition for producing a polypropylene-based resin foam molded article according to [Item 28], wherein the amide compound is at least one amide compound represented by the following general formula (5).
[In the formula, R ¹⁶ , R ¹⁷ , and R ¹⁸ are the same or different, and are represented by the following general formula (f), which are linear or branched alkyl or alkenyl groups or phenyl groups having 5 to 20 carbon atoms. It represents a cycloalkyl group to be used, or an alkyl-substituted cycloalkyl group represented by the following general formula (g). ]
[In the formula, x represents an integer of 1-8. ]
[In the formula, R ¹⁹ represents a linear or branched chain alkyl group having 1 to 4 carbon atoms. y represents an integer of 1-8. z represents an integer of 1 to 4. When z is 2 or more, each R ¹⁹ may be the same or different from each other. ]

[Item 30] The polypropylene according to any one of [Item 21] to [Item 29], wherein the content of the amide compound is in the range of 0.001 to 10 parts by weight with respect to 100 parts by weight of the polypropylene resin. Polypropylene resin composition for producing foamed molded articles.

[Item 31] The polypropylene-based resin foam molded article according to [Item 30], wherein the content of the amide compound is in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the polypropylene-based resin. Polypropylene resin composition.

[Item 32] The polypropylene resin foam molding according to any one of [Item 21] to [Item 31], wherein the melt flow rate of the polypropylene resin at 230 ° C. and a load of 2160 g is 0.1 to 60.0 g / 10 minutes. Polypropylene resin composition for body manufacturing.

[Item 33] The polypropylene-based resin composition for producing a polypropylene-based resin foam molded article according to [Item 32], wherein the melt flow rate of the polypropylene-based resin at 230 ° C. and a load of 2160 g is 0.2 to 40.0 g / 10 minutes. Stuff.

[Item 34] At least one amide compound selected from the group consisting of (i) polypropylene-based resin, an amide compound represented by the following general formula (1), and an amide compound represented by the general formula (2) is 240 to 330. A step of heating to a temperature range of ℃, melting and mixing, and dissolving the amide compound in the melted polypropylene resin.
(Ii) A step of cooling the molten polypropylene-based resin composition obtained in step (i) to a temperature of 80 ° C. or lower and precipitating fine acicular crystals of an amide compound in the solidified polypropylene-based resin composition.
A method for producing a polypropylene-based resin composition for producing a polypropylene-based resin foam molded article, which comprises the above.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, 6 to alicyclic amine residue or carbon atoms of 5 to 30 carbon atoms Represents 30 aromatic amine residues. ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ]

According to the method for producing a polypropylene-based resin foam molded article of the present invention, it is possible to increase the foaming ratio without impairing the mechanical properties such as heat resistance and mechanical strength inherent in polypropylene-based resin, which was obtained by this method. The polypropylene-based resin foam molded product can contribute to reduction of fuel consumption by weight reduction in automobile applications where excellent mechanical properties are required. Further, it goes without saying that the polypropylene-based resin foam molded product of the present invention is useful as a highly foamed molded product having excellent mechanical properties in automobile applications where fuel consumption reduction by weight reduction is required, and resource saving in recent years. It can be used for various purposes according to the needs of.

Hereinafter, the present invention will be described in detail.

<Polypropylene resin composition>
The polypropylene-based resin composition in the present invention is characterized by containing at least one specific amide compound for the purpose of producing a polypropylene-based resin foam molded product, and in particular, the aspect of the amide compound is a fine needle-like crystal. Is preferable.

The production method is not particularly limited as long as a desired resin composition can be obtained, and production methods known in the art, for example, polypropylene-based resins (powder or flakes), amide compounds, and fatty acid calcium salts described below. , And a method of mixing other additives as needed can be used. For example, there is also a method in which a polypropylene resin, an amide compound, and other additives, if necessary, are mixed, kneaded at a predetermined temperature, the amide compound is melt-mixed in the molten polypropylene resin, and then cooled and solidified. Can be mentioned. Further, a method in which the amide compound is dissolved in the molten polypropylene-based resin at the time of the melt mixing and then cooled and solidified is preferable because the contained amide compound becomes finer needle-like crystals.

Polypropylene-based resin The polypropylene-based resin used in the present invention is a polymer containing propylene as a main constituent, and specifically, a propylene homopolymer or a random or blocked propylene copolymer mainly composed of propylene. Can be mentioned.

Examples of the propylene copolymer include random copolymers of propylene and comonomer or block copolymers containing propylene as a main component. Examples of the comonomer include 1-alkenes other than propylene (ethylene, 1-butene, 1-pentene, 1-hexene, 4-methylpentene, etc.) and other comonomeres such as styrene, maleic anhydride, (meth). Acrylic acid and the like can be exemplified. The copolymer may be a propylene-ethylene multi-element copolymer, for example, in addition to propylene and ethylene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 1,4-. Examples thereof include copolymers containing hexadiene and the like.

The content of propylene in the above-mentioned copolymer is preferably about 70 to 99% by weight, particularly preferably about 80 to 98% by weight. Further, among the copolymers mainly composed of propylene, a propylene-ethylene copolymer is preferable. As the propylene-ethylene copolymer, a copolymer having an ethylene content of about 1 to 30% by weight, particularly about 2 to 20% by weight is preferable.

In the present specification, the above-mentioned "ethylene content" means the ethylene content (content of structural portion derived from ethylene) contained in the propylene-ethylene copolymer. The ethylene content can generally be measured by the infrared spectral method (J.Polym.Sci., 7,203 (1964)).

In addition, the polypropylene-based resin may be used as a polymer blend containing a small amount of thermoplastic resin such as high-density polyethylene, polybutene-1, poly-4-methylpentene-1 and the like. However, when polymer blends are used, the content ratio of the polypropylene-based resin in these polymer blends is preferably about 70 to 99% by weight, particularly about 80 to 98% by weight, in the resin.

The melt flow rate of these polypropylene resins (hereinafter abbreviated as "MFR"; JIS K-7210 (1999)) is preferably 0.1 to 60 g / 10 minutes, more preferably 0.2 to 40 g / min. It is recommended that it be in the range of 10 minutes, particularly preferably 0.5 to 20 g / 10 minutes. Similarly, it is recommended that the MFR of the polymer blend be in the range of 0.1 to 60 g / 10 minutes, preferably 0.2 to 40 g / 10 minutes, and more preferably 0.5 to 20 g / 10 minutes. The above MFR is a numerical value at a load of 2160 g and 230 ° C.

If the MFR is less than 0.1 g / 10 minutes, the melt tension at the time of foaming is too high and it is difficult to foam, and if the MFR exceeds 60 g / 10 minutes, rapid foaming tends to cause foam breakage. It becomes difficult to raise.

It is also possible to use high melt tension polypropylene having a free-ended long chain branch in order to suppress foam breakage during foaming.

Amide Compound The amide compound used in the present invention is at least one amide compound selected from the group consisting of the amide compound represented by the following general formula (1) and the amide compound represented by the general formula (2).
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, 6 to alicyclic amine residue or carbon atoms of 5 to 30 carbon atoms Represents 30 aromatic amine residues. ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ]

Among the above amide compounds, the preferred amide compound is recommended to be at least one amide compound represented by the following general formula (3).
[In the formula (3), R ⁷ is a saturated or unsaturated aliphatic dicarboxylic acid residue having 2 to 18 carbon atoms, preferably 3 to 12 carbon atoms, particularly preferably 4 to 8 carbon atoms, and 3 to 18 carbon atoms. It represents preferably 6 to 10, particularly preferably 6 to 8 saturated or unsaturated alicyclic dicarboxylic acid residues, or 6 to 18 carbon atoms, and R ⁸ and R ⁹ are the same. Or differently, it represents a cycloalkyl group having 5 to 18 carbon atoms, and a group represented by the following general formula (a), general formula (b), general formula (c) or general formula (d), respectively.
[In formulas (a) to (d), R ¹⁰ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 6 to 10 carbon atoms, or a phenyl group, and R ¹¹ represents a linear or branched alkyl group having 1 to ¹² carbon atoms, R ¹² represents a linear or branched alkylene group having 1 to 4 carbon atoms, and R ¹³ represents a linear or branched alkylene group having 1 to 4 carbon atoms. Represents 1 to 4 linear or branched alkylene groups). ]

Among them, R ⁷ is an aromatic dicarboxylic acid residue represented by the following general formula (e), and R ⁸ and R ⁹ are the same or different alkyl groups having 1 to 4 carbon atoms, respectively. It is recommended that the amide compound represented by the above general formula (3) is at least one amide compound which is a cyclohexyl group which may be substituted with.

Further, among the amide compounds represented by the general formula (3), 2,6-naphthalenedicarboxylic acid dicyclohexylamide is particularly recommended from the viewpoint of the effect of the present invention.

Among the amide compounds represented by the general formula (1), at least one amide compound represented by the following general formula (4) is recommended as a preferable amide compound.
[In the formula, R ¹⁴ is a saturated or unsaturated aliphatic tricarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic tricarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic tricarboxylic acid having 6 to 18 carbon atoms. Represents a residue. Three ^{R 15} are the same or different, respectively, saturated or unsaturated aliphatic amine residue having 5 to 30 carbon atoms, having 5 to 30 carbon atoms alicyclic amine residue or C6-30 Represents an aromatic amine residue. ]

Among the amide compounds represented by the general formula (4), at least one amide compound represented by the following general formula (5) is recommended as a preferable amide compound.
[In the formula, R ¹⁶ , R ¹⁷ , and R ¹⁸ are the same or different, and are represented by the following general formula (f), which are linear or branched alkyl or alkenyl groups or phenyl groups having 5 to 20 carbon atoms. It represents a cycloalkyl group to be used, or an alkyl-substituted cycloalkyl group represented by the following general formula (g). ]
[In the formula, x represents an integer of 1-8. ]
[In the formula, R ¹⁹ represents a linear or branched chain alkyl group having 1 to 4 carbon atoms. y represents an integer of 1-8. z represents an integer of 1 to 4. When z is 2 or more, each R ¹⁹ may be the same or different from each other. ]

Within the scope of the present specification and patent claims, a saturated or unsaturated aliphatic polycarboxylic acid residue represented by R ¹ , a saturated or unsaturated alicyclic polycarboxylic acid residue or an aromatic polycarboxylic acid residue. Refers to a group obtained by removing all carboxyl groups from the corresponding polycarboxylic acid.

Similarly, in the specification and claims, an aliphatic dicarboxylic acid residue of a saturated or unsaturated represented by R ^7, alicyclic dicarboxylic acid residue or an aromatic dicarboxylic acid residue of a saturated or unsaturated Refers to a group obtained by removing two carboxyl groups from the corresponding dicarboxylic acid.

Similarly, in the specification and claims, aliphatic tricarboxylic acid residue of a saturated or unsaturated represented by R ^14, alicyclic tricarboxylic acid residue, or aromatic tricarboxylic acid residues of saturated or unsaturated Refers to a group obtained by removing three carboxyl groups from the corresponding tricarboxylic acid.

Also, within the scope of this specification and patent claims, saturated or unsaturated aliphatic poly (di, tri) carboxylic acid residues represented by R ¹ , R ⁷ or R ¹⁴ , saturated or unsaturated alicyclic group. The carbon number of a poly (di, tri) carboxylic acid residue or an aromatic poly (di, tri) carboxylic acid residue is the number of carbon atoms as a poly (di, tri) carboxylic acid residue (ie, the corresponding poly (ie, corresponding poly). Di, tri) The number of carbon atoms corresponding to the carboxyl group contained in the carboxylic acid (2 to 6 in the case of polycarboxylic acid, 2 in the case of dicarboxylic acid, 3 in the case of tricarboxylic acid) was subtracted from the number of carbon atoms. Things).

The amide compound represented by the general formula (1) is the general formula (1a).
[In the formula, R ²⁰ is synonymous with R ¹ in the general formula (1). Further, n has the same meaning as n in the general formula (1). ]
Aliphatic, alicyclic, or aromatic polycarboxylic acids represented by the general formula (1b).
[In the formula, R ²¹ is synonymous with R ² in the general formula (1). ]
It can be easily prepared by amidating one or two aliphatic, alicyclic or aromatic monoamines represented by.

The amide compound according to the present invention can be produced according to a known method or a known method. For example, according to the description of JP-A-5-310665, JP-A-7-188246, JP-A-7-309821, JP-A-2005-528498, etc., the amidation reaction is carried out using polycarboxylic acid and monoamine as raw materials. It can be manufactured by doing. It can also be produced by subjecting reactive derivatives such as acid anhydrides and chlorides of these polycarboxylic acids and ester compounds of the polycarboxylic acids to lower alcohols having about 1 to 4 carbon atoms for amidation. The amide compound produced according to a known method may contain some impurities, but is preferably 90% by weight or more, more preferably 95% by weight or more, and particularly preferably 97% by weight or more. Examples of impurities include partial amidates derived from reaction intermediates or unreactants, imide compounds derived from by-reactants, and the like.

Examples of the aliphatic polycarboxylic acid include saturated or unsaturated aliphatic polycarboxylic acids having 2 to 18 carbon atoms, preferably 3 to 15 carbon atoms, and more specifically, malonic acid, diphenylmalonic acid, succinic acid, and the like. Phenylsuccinic acid, diphenylsuccinic acid, glutaric acid, 3,3-dimethylglutaric acid, adipic acid, pimeric acid, suberic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedic acid, Dicarboxylic acids such as 1,18-octadecanedic acid, 1,2,3-propanetricarboxylic acid, tricarboxylic acids such as 1,2,3-propentricarboxylic acid, 1,3,5-pentanetricarboxylic acid, ethanetetracarboxylic acid , Propanetetracarboxylic acid, pentantetracarboxylic acid, butanetetracarboxylic acid (particularly 1,2,3,4-butanetetracarboxylic acid), tetracarboxylic acid such as dodecanetetracarboxylic acid, pentacarboxylic acid such as pentanpentacarboxylic acid Hexacarboxylic acids such as acids and tetradecanehexacarboxylic acids are indicated.

Examples of the alicyclic polycarboxylic acid include alicyclic polycarboxylic acids having 3 to 18 carbon atoms, preferably 6 to 15 carbon atoms, and more specifically, 1,2-cyclohexanedicarboxylic acid and 1,3-. Dicarboxylic acids such as cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanediacetic acid, 2-norbornene-5,6-dicarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid, 1,2,3 -Tricarboxylic acids such as cyclohexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, tetrahydrofurantetracarboxylic acid, bicyclo [2.2.2 ] Tetracarboxylic acids such as octa-7-ene-2,3,5,6-tetracarboxylic acid, hexacarboxylic acids such as cyclohexanehexacarboxylic acid and the like are exemplified.

Examples of the aromatic polycarboxylic acid include aromatic polycarboxylic acids having 6 to 18 carbon atoms, preferably 6 to 15 carbon atoms, and more specifically, p-phenylenediacetic acid, p-phenylenediethaneic acid, and phthalic acid. Acid, 4-tert-butylphthalic acid, isophthalic acid, 5-tert-butylisophthalic acid, terephthalic acid, 1,8-naphthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7- Naphthalenedicarboxylic acid, diphenylic acid, 3,3'-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-binaphthyldicarboxylic acid, bis (3-carboxyphenyl) methane, bis (4-carboxyphenyl) Methan, 2,2-bis (3-carboxyphenyl) propane, 2,2-bis (4-carboxyphenyl) propane, 3,3'-sulfonyldibenzoic acid, 4,4'-sulfonyldibenzoic acid, 3, 3'-oxydibenzoic acid, 4,4'-oxydibenzoic acid, 3,3'-carbonyldibenzoic acid, 4,4'-carbonyldibenzoic acid, 3,3'-thiodibenzoic acid, 4,4'- Dicarboxylic acids such as thiodibenzoic acid, hemmellitic acid, trimesic acid, trimellitic acid, 2,5,7-naphthalene tricarboxylic acid, tricarboxylic acids such as 1,2,4-naphthalene tricarboxylic acid, pyromellitic acid, benzophenone tetracarboxylic acid Acid, biphenyltetracarboxylic acid, biphenyl ether tetracarboxylic acid, diphenylmethanetetracarboxylic acid, perylenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2 , 3,6,7-naphthalenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic acid, benzidine-3,3'-dicarboxy-N, N'-tetraacetic acid, diphenylpropanetetracarboxylic acid, phthalocyanine Examples thereof include tetracarboxylic acids such as tetracarboxylic acid, pentacarboxylic acids such as benzenepentacarboxylic acid, and hexacarboxylic acids such as benzenehexacarboxylic acid.

Among the above polycarboxylic acids, from the viewpoint of the effect of the present invention and the availability of raw materials, adipionic acid, pimelliic acid, suberic acid, azelaic acid, sebacic acid, 1,2,3-propentricarboxylic acid, 1 , 2,3,4-Butanetetracarboxylic acid and other aliphatic polycarboxylic acids, 1,4-cyclohexanedicarboxylic acid, 2-norbornene-5,6-dicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid and other fats Fragrances such as ring polycarboxylic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, trimesic acid, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid Polycarboxylic acids and the like are recommended, among which adipic acid, pimeric acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 1,2,3-propentricarboxylic acid, 1, 2,3,4-butanetetracarboxylic acid and trimesic acid are recommended.

Examples of the aliphatic monoamine include saturated or unsaturated aliphatic amines having 5 to 30 carbon atoms, preferably 5 to 20 carbon atoms, and more specifically, hexylamine, heptylamine, octylamine, nonylamine and decylamine. , Undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonadecilamine, icosylamine, henicosylamine, docosylamine, etc. are shown.

The alicyclic monoamine is a fat having 5 to 30 carbon atoms, preferably 5 to 28 carbon atoms, more preferably 5 to 18 carbon atoms, still more preferably 5 to 12 carbon atoms, and particularly preferably 7 to 10 carbon atoms. Acyclic monoamines are exemplified, and more specifically, cycloalkylamines having 5 to 18 carbon atoms, the general formula (6).
[In the formula, R ²² is synonymous with R ¹¹ in the general formula (b). ]
Compound represented by, or general formula (7)
[In the formula, R ²³ is synonymous with R ¹³ in the general formula (d). ]
The compound represented by is exemplified.

More specifically, cyclopentylamine, cyclohexylamine, 2-methylcyclohexylamine, 3-methylcyclohexylamine, 4-methylcyclohexylamine, 2,3-dimethylcyclohexylamine, 2,4-dimethylcyclohexylamine, 2-ethylcyclohexylamine. Amin, 3-ethylcyclohexylamine, 4-ethylcyclohexylamine, 2-n-propylcyclohexylamine, 3-n-propylcyclohexylamine, 4-n-propylcyclohexylamine, 2-isopropylcyclohexylamine, 3-isopropylcyclohexylamine, 4-Isopropylcyclohexylamine, 2-n-butylcyclohexylamine, 3-n-butylcyclohexylamine, 4-n-butylcyclohexylamine, 2-isobutylcyclohexylamine, 3-isobutylcyclohexylamine, 4-isobutylcyclohexylamine, 2- tert-Butylcyclohexylamine, 3-tert-butylcyclohexylamine, 4-tert-butylcyclohexylamine, 4-sec-butylcyclohexylamine, 4-n-amylcyclohexylamine, 4-isoamylcyclohexylamine, 4-sec-amylcyclohexylamine Amin, 4-tert-amylcyclohexylamine, 4-hexylcyclohexylamine, 4-heptylcyclohexylamine, 2-octylcyclohexylamine, 3-octylcyclohexylamine, 4-octylcyclohexylamine, 4-nonylcyclohexylamine, 4-decylcyclohexylamine Amin, 4-undecylcyclohexylamine, 4-dodecylcyclohexylamine, 4-cyclohexylcyclohexylamine, 4-phenylcyclohexylamine, cycloheptylamine, cyclododecylamine, cyclohexylmethylamine, α-cyclohexylamine, β-cyclohexylamine, α Examples thereof include -cyclohexylamine, β-cyclohexylamine, and γ-cyclohexylamine.

Examples of the aromatic monoamine include aromatic monoamines having 6 to 30 carbon atoms, preferably 5 to 20 carbon atoms, more preferably 7 to 18 carbon atoms, and further preferably 7 to 10 carbon atoms, and more specifically. Is the general formula (8)
[In the formula, R ²⁴ is synonymous with R ¹⁰ in the general formula (a). ]
Compound represented by, or general formula (9)
[In the formula, R ²⁵ is synonymous with R ¹² in the general formula (c). ]
The compound represented by is exemplified.

More specifically, aniline, o-toluidine, m-toluidine, p-toluidine, 2-ethylaniline, 3-ethylaniline, 4-ethylaniline, 2-propylaniline, 3-propylaniline, 4-propylaniline, o-Cumidine, m-Cumidine, p-Cumidine, 2-n-butylaniline, 3-n-butylaniline, 4-n-butylaniline, 2-isobutylaniline, 3-isobutylaniline, 4-isobutylaniline, 2- sec-butylaniline, 3-sec-butylaniline, 4-sec-butylaniline, 2-tert-butylaniline, 3-tert-butylaniline, 4-tert-butylaniline, pn-amylaniline, p-isoamyl Aniline, p-sec-amylaniline, p-tert-amylaniline, 2-n-pentylaniline, 3-n-pentylaniline, 4-n-pentylaniline, 2-isopentylaniline, 3-isopentylaniline, 4 -Isopentylaniline, 2-sec-pentylaniline, 3-sec-pentylaniline, 4-sec-pentylaniline, 2-tert-pentylaniline, 3-tert-pentylaniline, 4-tert-pentylaniline, 2-hexyl Anilin, 3-hexylaniline, 4-hexylaniline, 2-heptylaniline, 3-heptylaniline, 4-heptylaniline, 2-octylaniline, 3-octylaniline, 4-octylaniline, 2-nonylaniline, 3-nonyl Aniline, 4-nonylaniline, 2-decylaniline, 3-decylaniline, 4-decylaniline, undecylaniline, dodecylaniline, cyclohexylaniline, o-aminodiphenyl, m-aminodiphenyl, p-aminodiphenyl, benzylamine, α-phenylethylamine, β-phenylethylamine, α-phenylpropylamine, β-phenylpropylamine, γ-phenylpropylamine, 1-naphthylamine, 2-naphthylamine, 1-aminoanthracene, diphenylamine, dimethylaniline, diethylaniline, dipropylaniline, Diisopropylaniline, di-n-butylaniline, di-sec-butylaniline, di-tert-butylaniline, trimethylaniline, triethylaniline, tripropylaniline, tri-tert-butylaniline, anicidin, ethoxyaniline, dimethoxyaniline, diet Xyaniline, trimethoxyaniline, tri-n-butoxyaniline, benzylamine, methylbenzylamine, dimethylbenzylamine, trimethylbenzylamine, methoxybenzylamine, ethoxybenzylamine, dimethoxybenzylamine, α-phenylethylamine, methoxyphenylethylamine, dimethoxy Examples thereof include phenylethylamine and methylphenylpropylamine.

Among the above monoamines, from the viewpoint of the effect of the present invention and the availability of raw materials, an unsubstituted cyclohexylamine or a linear or branched alkyl group having 1 to 4 carbon atoms as a substituent (particularly). Cyclohexylamine having 1 to 3 (particularly 1) methyl group) is recommended.

Specific examples of particularly preferable alicyclic monoamines include cyclohexylamine, 2-methylcyclohexylamine, 3-methylcyclohexylamine, 4-methylcyclohexylamine, 2-ethylcyclohexylamine, 2-n-propylcyclohexylamine, and 2-iso. Examples thereof include -propylcyclohexylamine, 2-n-butylcyclohexylamine, 2-iso-butylcyclohexylamine, 2-sec-butylcyclohexylamine and 2-tert-butylcyclohexylamine.

The monoamine having the above-mentioned substituent may be any of a cis form, a trans form, and a mixture of these isomers.

In addition, preferred monoamines include aniline or aniline having 1 to 3 (particularly 1) linear or branched alkyl groups having 1 to 4 carbon atoms.

Among the compounds of the above general formula (3), preferably, R ⁷ is a saturated or unsaturated aliphatic dicarboxylic acid residue having about 1 to 12 carbon atoms, and a saturated or unsaturated alicyclic having about 6 to 10 carbon atoms. It represents a group dicarboxylic acid residue or an aromatic dicarboxylic acid residue having about 6 to 20 carbon atoms, and R ⁸ and R ⁹ are the same or different, and a cycloalkyl group having about 3 to 12 carbon atoms, or a general formula ( a), a group represented by the general formula (b), the general formula (c) or the general formula (d).

More preferably, R ⁷ is a saturated aliphatic dicarboxylic acid residue having about 4 to 8 carbon atoms, a saturated aliphatic dicarboxylic acid residue having about 6 to 8 carbon atoms, or an aromatic dicarboxylic acid residue having about 6 to 20 carbon atoms. It is a group, and R ⁸ and R ⁹ are substituted with a cyclohexyl group which may be substituted with one alkyl group having about 1 to 4 carbon atoms or an alkyl group having about 1 to 4 carbon atoms. It is also a good phenyl group.

More preferably, R ⁷ is an aromatic dicarboxylic acid residue having about 6 to 20 carbon atoms, and R ⁸ and R ⁹ may be substituted with one alkyl group having about 1 to 4 carbon atoms. Is the basis.

In particular, R ⁷ is an aromatic dicarboxylic acid residue represented by the following general formula (e), and R ⁸ and R ⁹ may be substituted with one alkyl group having about 1 to 4 carbon atoms. It is recommended to be a cyclohexyl group.

Among the diamide compounds represented by the general formula (2) or the general formula (3), preferable compounds are adipate dianilide, terephthalic acid di (cyclohexylamide), terephthalic acid di (2-methylcyclohexylamide), N, N. '-Dicyclohexyl-2,6-naphthalenedicarboxamide, N, N'-di (2-methylcyclohexyl) -2,6-naphthalenedicarboxamide, 3,9-bis [4- (N-cyclohexylcarbamoyl) phenyl]- 2,4,8,10-Tetraoxaspiro [5,5] undecane, 3,9-bis [4- (N-4-tert-butylcyclohexylcarbamoyl) phenyl] -2,4,8,10-tetraoxa Spiro [5,5] undecane, 3,9-bis {4- [N- (2,4-di-tert-butylcyclohexyl) carbamoyl] phenyl} -2,4,8,10-tetraoxaspiro [5, 5] Undecane and the like can be exemplified, and N, N'-dicyclohexyl-2,6-naphthalenedicarboxamide is recommended as a particularly preferable compound.

Among the triamide compounds in which n is represented by an integer of 3 in the general formula (1) (that is, the amide compound represented by the general formula (4)), as the amide compound represented by the general formula (5) or a specific compound, 1,2,3-Propanetricarboxylic acid trihexylamide, 1,2,3-propanetricarboxylic acid tridodecylamide, 1,2,3-propanetricarboxylic acid trioctadecylamide, 1,2,3-propanetricarboxylic acid trianilide, 1,2,3-Propanetricarboxylic acid tricyclohexylamide, 1,2,3-propanetricarboxylic acid tris (2-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tris (4-butylanilide), trimesic acid Trihexylamide, tridodecylamide trimethicate, trioctadecylamide trimethicate, trianilide trimethicate, tricyclohexylamide trimethicate, tristrimethicate (2-methylcyclohexylamide), tristrimethicate (4-butylanilide) are preferred. Among them, 1,2,3-propanetricarboxylic acid tris (2-methylcyclohexylamide), trimesic acid tricyclohexylamide and the like are exemplified as preferable compounds. Further, among them, particularly trimesic acid tricyclohexylamide and tris 1,2,3-propanetricarboxylic acid (2-methylcyclohexylamide) are recommended as the most preferable compounds.

Among the amide compounds (that is, tetraamide compounds) in which n is represented by an integer of 4 in the general formula (1), preferred compounds are 1,2,3,4-butanetetracarboxylic acid tetrahexylamide, 1,2, 3,4-Butanetetracarboxylic acid tetradodecylamide, 1,2,3,4-butanetetracarboxylic acid tetraoctadecylamide, 1,2,3,4-butanetetracarboxylic acid tetraanilide, 1,2,3,4 -Butanetetracarboxylic acid tetracyclohexylamide, 1,2,3,4-butanetetracarboxylic acid tetrakis (2-methylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetrahexyl (4-butylanilide) Of these, 1,2,3,4-butanetetracarboxylic acid tetracyclohexylamide is particularly preferable.

The amide compounds according to the present invention can be used alone or in combination of two or more.

It is recommended that the maximum particle size of the amide compound before melt-mixing with the polypropylene resin is preferably 20 μm or less, more preferably 10 μm or less, and particularly preferably 5 μm or less. If the maximum particle size exceeds 20 μm, the amide compound may be poorly dispersed during melt mixing, or the amide compound may be difficult to dissolve in the molten polypropylene resin, resulting in undissolved residue. The undissolved amide compound that remains undissolved causes enlargement (enlargement) of crystals in the next molding process, lowers the impact strength of the obtained molded product, and causes breakage during secondary processing. Not preferred. Here, the maximum particle size refers to the particle size when measured by a method based on a laser diffraction method.

It is recommended that the content or addition amount of the amide compound according to the present invention is preferably 0.0001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, based on 100 parts by weight of the polypropylene resin. Will be done.

<foaming agent>
The foaming agent that can be used in the present invention is not particularly limited as long as it can be usually used for injection foam molding such as a chemical foaming agent and a physical foaming agent. The chemical foaming agent is supplied to an injection molding machine after being mixed with the resin composition in advance and decomposed in a cylinder to generate a gas such as carbon dioxide gas. Examples of the chemical foaming agent include inorganic chemical foaming agents such as sodium bicarbonate and ammonium carbonate, and organic chemical foaming agents such as azodicarbonamide and N, N'-dinitrosopentatetramine. The physical foaming agent is injected into the molten resin in the cylinder of the molding machine as a gaseous or supercritical fluid, dispersed or dissolved, and functions as a foaming agent by releasing the pressure after injection into the mold. It is a thing. Examples of the physical foaming agent include aliphatic hydrocarbons such as propane and butane, alicyclic hydrocarbons such as cyclobutane and cyclopentane, halogenated hydrocarbons such as chlorodifluoromethane and dichloromethane, nitrogen, carbon dioxide, air and the like. Inorganic gas can be mentioned. These may be used alone or in combination of two or more.

Among these foaming agents, one of the preferable foaming agents is an inorganic chemical foaming agent that can be used in a normal injection molding machine and can easily obtain uniform and fine bubbles. In these inorganic chemical foaming agents, foaming aids such as organic acids such as citric acid and inorganic fine particles such as talc are used as necessary in order to make the bubbles of the foam molded product stable and uniform. Etc. may be added. Usually, the inorganic chemical foaming agent is preferably used as a masterbatch of a polyolefin resin having a concentration of 10 to 50% by mass from the viewpoints of handleability, storage stability, and dispersibility in polypropylene resin.

The amount of the inorganic chemical foaming agent added varies depending on the type, the concentration in the masterbatch, and the desired foaming ratio, but is preferably about 0.1 to 30 parts by weight, more preferably about 100 parts by weight, based on 100 parts by weight of the polypropylene resin. Is used in the range of about 0.5 to 20 parts by weight. By using it in this range, it is easy to obtain an injection-foamed molded product having uniform and fine bubbles at a foaming ratio of 2 times or more economically.

Moreover, among the said foaming agents, another preferable foaming agent is carbon dioxide gas which is a physical foaming agent. Carbon dioxide gas is usually supplied by being press-fitted into an extruder in order to foam a thermoplastic resin such as a polypropylene resin, and carbon dioxide in a supercritical state, a subcritical state, or liquefied carbon dioxide is used. You can also. The carbon dioxide gas can form finer bubbles than the conventional foaming agent, and can improve the surface smoothness and flexibility of the obtained foam.

The amount of the physical foaming agent such as carbon dioxide that is press-fitted into the extruder may be appropriately adjusted according to the expansion ratio of the polypropylene resin foam, but if the amount used is small, the polypropylene resin foam While the foaming ratio may be low and the lightness and heat insulating properties may be lowered, if the amount used is large, foaming may occur in the mold, causing foam breakage, or large voids in the polypropylene-based resin foam. It is preferably about 1 to 10 parts by weight, more preferably about 2 to 8 parts by weight, and about 3 to 6 parts by weight with respect to 100 parts by weight of the polypropylene-based resin. Is particularly preferable.

When carbon dioxide gas is used as a foaming agent, sodium hydrogen carbonate can also be used as the foaming agent for generating carbon dioxide gas. In the case of sodium hydrogen carbonate, it can also be used as a masterbatch in order to improve the dispersibility in the resin.

A masterbatch can usually be produced by kneading an additive or the like in a thermoplastic base resin at a high concentration to form a pellet. The base resin is not particularly limited as long as it has excellent compatibility with polypropylene-based resins, and for example, polyolefin-based resins such as homopolypropylene, block polypropylene, random polypropylene, low-density polyethylene, and high-density polyethylene are preferable. Can be used for.

<Other additives>
The polypropylene-based resin composition according to the present invention may be appropriately blended with a conventionally known modifier for polyolefin, depending on the purpose of use and its use, to the extent that the effects of the present invention are not impaired. In particular, the additive that inhibits the effect of the amide compound according to the present invention is preferably blended within a range that does not impair the effect.

Examples of such modifiers for polyolefins include various additives described in "Positive List Additives Handbook" (May 2001) edited by the Sanitary Council for Polyolefins, etc., and more specifically, they are stable. Agents (metal compounds, epoxy compounds, nitrogen compounds, phosphorus compounds, sulfur compounds, phenolic compounds, UV absorbers, etc.), surfactants (nonionic, anionic, amphoteric, cationic, etc.), lubricants (Alphatic hydrocarbons such as paraffin and wax, higher fatty acids with 8 to 22 carbon atoms, aliphatic alcohols with 8 to 18 carbon atoms, polyglycols, higher fatty acids with 4 to 22 carbon atoms and 4 to 18 carbon atoms. Esther with an aliphatic monovalent alcohol of about 8 to 22, higher fatty acid amide having about 8 to 22 carbon atoms, silicone oil, rosin derivative, etc.), filler (oxide, hydroxide, carbonate, sulfate, silicate, etc.) ), Polymer additives, and various additives such as organic nucleating agents other than the amide compound according to the present invention are exemplified.

Examples of the organic nucleating agent include conventionally known nucleating agents for polypropylene.

Specifically, the following general formula (10)
[In the formula, R ²⁶ represents a hydrogen atom, a linear or branched alkyl group having about 1 to 12 carbon atoms, a phenyl group, a benzyl group, a cyclohexyl group or a carboxyl group, and a is an integer of about 0 to 12. Represents A, and represents a group represented by the following general formula (h), general formula (i), general formula (j), general formula (k) or general formula (l).
(In formulas (h) to (l), R ²⁷ represents a hydrogen atom, a linear or branched alkyl group having about 1 to 12 carbon atoms or a halogen atom, and b is an integer of about 1 to 4. c represents an integer of about 1 to 6. When b or c is an integer of 2 or more, two or more R ^20s may be the same or different). ]
Compound represented by, calcium salt of organic dibasic acid, magnesium salt, barium salt (for example, calcium pimelliate, calcium terephthalate, etc.), potassium 12-hydroxystearate, magnesium benzoate, magnesium succinate, magnesium phthalate, etc. , Aromatic sulfonic acid compounds such as sodium benzene sulfonate and sodium naphthaline sulfonate, dicarboxylic acid diesters or tricarboxylic acid triesters, tetraoxaspiro compounds, imidecarboxylic acid derivatives, phthalocyanines such as phthalocyanine blue, quinacridone, quinacridone. Examples thereof include quinacridone-based pigments such as quinone, and two-component systems composed of the organic dibasic acid and oxides, hydroxides, or salts of Group IIA metals of the periodic table.

<Manufacturing method of polypropylene resin foam molded product>
The method for producing a polypropylene-based resin foam molded article of the present invention uses an amide compound according to the present invention, preferably a polypropylene-based resin composition containing fine needle-like crystals thereof, and fine needle-like crystals composed of the amide compound. It is characterized in that a polypropylene-based resin foam-molded article having an excellent mechanical property and a high foaming ratio is produced by foam-molding in a state in which Further, a secondary processed molded product can also be obtained by secondary processing the obtained polypropylene-based resin foam molded product by a method adopted in the art.

Hereinafter, the recommended polypropylene-based resin composition for producing a polypropylene-based resin foam-molded article and the production conditions of the polypropylene-based resin foam-molded article will be described in detail along with the production process.

First, as a method for producing a polypropylene-based resin composition, the following procedure (step) is usually adopted.

A polypropylene resin (powder or flakes), an amide compound and, if necessary, other additives are mixed to obtain a dry blend. The mixing method is not particularly limited, and the mixture is mixed using a known mixer such as a Henschel mixer, a V blender, a super mixer, or a tumbler. The mixing temperature is usually about room temperature to 100 ° C., and the mixing time is generally about 1 to 60 minutes, although it depends on the rotation speed of the device and the like.

Further, instead of the dry blend, for example, a high-concentration additive formulation (for example, the above-mentioned additive) in which a polypropylene resin (powder or flake) and an amide compound or, if necessary, another additive is blended in a high concentration. As a polypropylene resin (powder or flakes) and an unkneaded raw material containing other additives as needed (high-concentration additive compounding composition) It can also be used.

Subsequently, the temperature (Tm) at which the polypropylene resin melts the dry blend or the high-concentration additive compound composition by a single-screw or twin-screw extruder, a tandem type kneading extruder, or the like adopted in the technical field. ) Above, preferably, after kneading at a kneading temperature equal to or higher than the temperature at which the amide compound dissolves in the polypropylene resin (hereinafter referred to as “T ₂ ”), the molten polypropylene resin composition discharged from the die is quickly mixed with water or the like. It is guided to the refrigerant tank of the above and cooled and solidified. Next, the cooled and solidified strand-shaped polypropylene-based resin composition is cut to an appropriate length with a breaking machine such as a pelletizer to obtain a pellet-shaped polypropylene-based resin composition. The "melting temperature of the amide compound" referred to here means that the amide compound existing in the polypropylene-based resin composition (composition that matches the composition of the target polypropylene-based resin molded product) is completely dissolved. Means temperature.

The specific temperature range of T ₂ varies depending on the type of resin, the type of amide compound, the blending amount, etc., and cannot be unconditionally defined, but is usually about 240 to 330 ° C, preferably about 250 to 320 ° C. Range is recommended.

Here, from the viewpoint of the strength of the polypropylene-based resin foam molded product, it is recommended that the amide compound in the polypropylene-based resin composition is a needle-like crystal, and the needle-like crystal is finer. As a method for obtaining a polypropylene-based resin composition containing an acicular crystalline amide compound, there is also a method in which an acicular crystalline amide compound is added in advance and kneaded under conditions in which the amide compound is not dissolved. As in the example, in order to obtain finer acicular crystals, the added amide compound is once dissolved in the molten polypropylene resin, and then precipitated as acicular crystals in the polypropylene resin when cooled and solidified. That is, the step of heating the composition containing the polypropylene resin and the amide compound to dissolve the amide compound in the molten polypropylene resin, and cooling the polypropylene resin composition in the molten state obtained in the above step. Then, the method by the step of precipitating the crystal of the amide compound is effective.

Subsequently, the following procedure (step) is usually adopted as a method for producing the polypropylene-based resin foam molded product.

The polypropylene-based resin foam molded product according to the present invention is obtained from the above-mentioned polypropylene-based resin composition by an in-mold foam molding method, an injection foam molding method, a press foam molding method, an extrusion foam molding method, and a stampable. It can be molded by a commonly used foam molding method such as a foam molding method. Further, the foam molded product of the present invention can be made into a decorative foam molded product by laminating skin materials by a method such as insert molding or adhesion.

What is important here is that fine acicular crystals of the amide compound are present in the polypropylene-based resin composition and the polypropylene-based resin molded product at the time of foam-molding the polypropylene-based resin molded product, and in particular, the crystals are present. It is to exist uniformly.

For example, as a method for uniformly presenting fine acicular crystals of the amide compound at the time of foam molding, the following method can be mentioned.

The first method is to mix a foaming agent with the polypropylene resin composition for foam molding containing fine needle-like crystals of the amide compound, and then heat and mix in a temperature range in which the amide compound does not dissolve in the polypropylene resin. A method of foam molding can be mentioned.

Here, the temperature range in which the amide compound does not dissolve in the polypropylene resin, preferably _{(T 1 + 10 ℃) ~} (T 2 -10 ℃), more preferably _{(T 1 + 15 ℃) ~} (T 2 -15 ° C.), in particular a temperature range of _{(T 1 + 20 ℃) ~} (T 2 -15 ℃) is recommended.

Here, T ₁ is the melting point of the polypropylene-based resin used, and T ₂ is as described above. Incidentally, the relationship of the temperature _{range, (T 1 + 10 ℃)} <(T 2 -10 ℃), (T 1 + 15 ℃) <(T 2 -15 ℃), or _{(T 1 + 20 ℃) <} (T ₂ -15 ℃) is established.

More specifically, the temperature range is about 190 to 260 ° C., preferably about 200 to 240 ° C., and more preferably about 200 to 230 ° C., although it depends on the type and amount of the amide compound. By setting the temperature to 190 ° C. or higher, the generation of unmelted resin is suppressed, and by setting the temperature to 260 ° C. or lower, there is a tendency to significantly improve the physical properties such as the strength of the polypropylene-based resin foam molded product.

In the second method, the polypropylene-based resin composition for foam molding containing crystals of the amide compound is heated again to a temperature at which the amide compound dissolves in the molten polypropylene-based resin, and then cooled and solidified to the foaming temperature, where the foaming agent is used. Is mixed and foamed, or the molded product is completely cooled and solidified to form a molded product, and then the molded product is heated to the foaming temperature again and then a foaming agent is mixed and foamed.

The foaming temperature varies depending on the resin, the type of foaming agent, the foaming ratio, etc., but is usually preferably 120 to 240 ° C, more preferably 150 to 240 ° C, still more preferably 150 to 220 ° C, and particularly preferably 150 to. A temperature range of 180 ° C is recommended.

The β crystal content in the molded product is not particularly limited as long as the effect of the present invention is exhibited, but is preferably about 20 to 90%, preferably about 50 to 90%, from the viewpoint of foam moldability. More preferably, and particularly preferably about 60 to 85%.

For the β crystal content, a sample obtained by cutting a polypropylene-based resin molded product into an appropriate size is differentially scanned by a DSC device (“Diamond DSC” manufactured by PerkinElmer) in a nitrogen atmosphere at a heating rate of 20 ° C./min. It is a value obtained from the calorific value of the α crystal and β crystal of the DSC thermogram obtained at this time according to the following formula.
β crystal content (%) = 100 × H _β / (H _α + H _β )
[In the formula, H _β indicates the amount of heat of fusion of β crystal, and H _α indicates the amount of heat of fusion of α crystal. ].

The foaming ratio of the polypropylene-based resin foam molded product according to the present invention is not particularly limited, but is usually about 1.2 to 100 times, preferably about 1.5 to 60 times, and more preferably about 2.0 to 40 times. It is recommended to be in the range of.

The polypropylene-based resin foam molded product according to the present invention may be further subjected to secondary processing using a method such as a normal thermoforming method such as vacuum forming or compressed air forming to obtain a secondary processed molded product having a desired shape. it can.

The polypropylene-based resin foam molded product according to the present invention thus obtained is lightweight and has excellent physical properties such as strength, and can be used in the same fields as those in which conventionally known polypropylene-based resin molded products have been used. Can be done. In particular, it can be used as a molded product such as an automobile part, a mechanical optical part, a chemical industry part, and a home electric appliance part. Further, the obtained foam molded product has excellent heat insulating properties, and can be used in the fields of automobile parts, electric parts, building materials and the like.

Further, the secondary processed molded product after the secondary processing can also be used in the same field as the conventional polypropylene-based resin molded product has been used.

Examples and comparative examples are shown below, and the present invention will be described in detail, but the present invention is not limited by these examples. The presence or absence of acicular crystals of the amide compound in the polypropylene resin composition in Examples and Comparative Examples, the β crystal content of the polypropylene resin composition, the expansion ratio, the bending strength of the polypropylene resin foam molded product, and the like. The specific strength was determined by the following method.

<Evaluation of polypropylene resin composition and molded product before foam molding>
(1) Presence or absence of needle-like crystal formation of the amide compound The presence or absence of needle-like crystal formation of the amide compound in the polypropylene-based resin composition or molded product is determined by using an optical microscope attached to a hot stage. The presence or absence of acicular crystal formation was visually confirmed by observing with a microscope while the polypropylene-based resin molded product was heated to 180 ° C. and kept at the same temperature.

(2) Measurement of β-crystal content The β-crystal content is a differential scanning calorimeter (Perkin) obtained by cutting a resin composition or a molded product into an appropriate size in a nitrogen atmosphere at a heating rate of 20 ° C./min. Differential scanning calorimetry (DSC analysis) was performed by "Diamond DSC" manufactured by Elmer Co., Ltd., and the calorimetry of α and β crystals of the DSC thermogram obtained at this time was calculated according to the following formula.
β crystal content (%) = 100 × H _β / (H _α + H _β )
[In the formula, H _β represents the amount of heat of fusion of β crystals, and H _α represents the amount of heat of fusion of α crystals. ].

(3) Foaming characteristics (foaming magnification)
For the evaluation of the foaming characteristics, the foaming ratio was measured by the following method using a resin composition or a molded product before foam molding as a sample.
The sample was molded while being housed in the cavity of a split mold, heated to 155 ° C., infused with carbon dioxide in a supercritical state at a pressure of 20 MPa, and impregnated for 20 minutes. After impregnating for 20 minutes, the pressure is released at a depressurizing rate of 10 MPa / sec to obtain a foam, and then the mass and buoyancy of the obtained foam are measured by the balance method, and the density and foaming after foaming are measured. The foaming ratio was determined from the ratio with the previous density. It can be said that the higher the foaming ratio, the better the foamability and the better the foaming characteristics.

<Evaluation of foam molded product>

(4) Bending strength and specific strength The bending strength (MPa) was measured according to JIS K 7203 (1982) using a universal material testing machine (manufactured by Instron).
The test temperature was 25 ° C. and the test speed was 10 mm / min.
Furthermore, from the obtained bending strength, the specific strength, which is the strength per density, was determined using the following formula.
Specific strength (kN ・ m / kg) = bending strength (MPa) / density (g / cm ³ )
As the density, the density of polypropylene was 0.9 g / cm ³ , and the density was divided by the expansion ratio.
It can be said that the larger the values of bending strength and specific strength, the better the mechanical strength.

[Example 1]
100 parts by weight of polypropylene homopolymer (MFR = 10 g / 10 min (load 2160 g, temperature 230 ° C.), melting point; 168 ° C.) as polypropylene resin, 2,6-naphthalenedicarboxylic acid dicyclohexylamide (amide compound 1, new) as amide compound 0.2 parts by weight of "Ngester NU-100" manufactured by Nippon Rika Co., Ltd., and 0.05 weight of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd., trade name "Ca-St") as other additives. Part, tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane (manufactured by BASF Japan Co., Ltd., trade name "IRGANOX1010") 0.05 parts by weight, tetrakis (2) , 4-Di-tert-butylphenyl) Phosphite (manufactured by BASF Japan, Inc., trade name "IRGAFOS168") was dry-blended in an amount of 0.05 parts by weight. The dry blend is melt-mixed at a heating temperature of 280 ° C. using a kneading temperature (resin temperature) at a twin-screw extruder (L / D = 45, manufactured by Technobel Co., Ltd.) with a screw diameter of 15 mm to obtain the amide compound. Was melted, the extruded strand was cooled, and the extruded strand was cut with a pelletizer to prepare a polypropylene resin composition (steps (i) to (ii)). The extruded strand was transparent. It was also confirmed visually.

Subsequently, the obtained polypropylene-based resin composition was molded under the conditions of an injection temperature (heating temperature) of 280 ° C. and a mold temperature (cooling temperature) of 40 ° C. to obtain a polypropylene-based resin molded product (step (iii). )). Using the obtained polypropylene-based resin molded product, the foaming characteristics (foaming ratio) were determined by the method (3) above, and the results are shown in Table 1. Further, as a result of confirming the formation state of acicular crystals of the amide compound by the method (1) above and the β crystal content by the method (2), the formation of fine acicular crystals of the amide compound was confirmed. The β crystal content of% or more was confirmed.

Next, the obtained molded product was placed in a mold having a width of 10 mm, a height of 4 mm, and a length of 65 mm, and then molded while being housed in the cavity of the split mold, and then heated to 155 ° C. Then, carbon dioxide in a supercritical state at a pressure of 20 MPa was injected, and carbon dioxide was impregnated for 20 minutes. Then, by releasing the pressure, a foam molded product having a foaming ratio of 2.3 times was obtained (step (iv)). Bending strength and specific strength were measured using the obtained foamed molded product, and the results are summarized in Table 1.

[Example 2]
Except that the blending amount of amide compound 1 was changed from 0.2 parts by weight to 0.1 parts by weight, the heating temperature during melt mixing was changed from 280 ° C to 270 ° C, and the heating temperature during molding production was changed from 280 ° C to 270 ° C. The same procedure as in Example 1 was carried out to obtain a polypropylene-based resin molded product and a polypropylene-based resin foam molded product. The β crystal content, foaming ratio, bending strength, and specific strength were measured using the obtained polypropylene-based resin molded product and polypropylene-based resin foam molded product. The results obtained are summarized in Table 1. Further, as a result of confirming the formation state of needle-like crystals of the amide compound and the β crystal content in the molded product in the same manner as in Example 1, the formation of fine needle-like crystals of the amide compound was confirmed, and 80% or more. The β crystal content was confirmed.

[Example 3]
Except for changing the blending amount of amide compound 1 to 0.05 parts by weight, the heating temperature of 280 ° C. during melt mixing to 260 ° C., and the heating temperature of 280 ° C. during molding production to 260 ° C. The same procedure as in Example 1 was carried out to obtain a polypropylene-based resin molded product and a polypropylene-based resin foam molded product. The β crystal content, foaming ratio, bending strength, and specific strength were measured using the obtained polypropylene-based resin molded product and polypropylene-based resin foam molded product. The obtained results are summarized in Table 1. Further, as a result of confirming the formation state of needle-like crystals of the amide compound and the β crystal content in the molded product in the same manner as in Example 1, fine needles of the amide compound were confirmed. The formation of compound crystals was confirmed, and the β crystal content of 80% or more was confirmed.

[Example 4]
A polypropylene-based resin molded product and a polypropylene-based resin foam molded product were obtained in the same manner as in Example 3 except that the cooling temperature of 40 ° C. during the production of the molded product was changed to 80 ° C. The β crystal content, foaming ratio, bending strength, and specific strength were measured using the obtained polypropylene-based resin molded product and polypropylene-based resin foam molded product. The results obtained are summarized in Table 1. Further, as a result of confirming the formation state of needle-like crystals of the amide compound and the β crystal content in the molded product in the same manner as in Example 1, the formation of fine needle-like crystals of the amide compound was confirmed, and 80% or more. The β crystal content was confirmed.

[Example 5]
As the amide compound, 3,9-bis [4- (N-cyclohexylcarbamoyl) phenyl] -2,4,8,10-tetraoxaspiro [5.5] undecane (amide compound 2) was used instead of amide compound 1. A polypropylene-based resin molded product and a polypropylene-based resin foam molded product were obtained in the same manner as in Example 2 except for the above. The β crystal content, foaming ratio, bending strength, and specific strength were measured using the obtained polypropylene-based resin molded product and polypropylene-based resin foam molded product. The results obtained are summarized in Table 1. Further, as a result of confirming the formation state of needle-like crystals of the amide compound and the β crystal content in the molded product in the same manner as in Example 1, the formation of fine needle-like crystals of the amide compound was confirmed, and 80% or more. The β crystal content was confirmed.

[Example 6]
The same procedure as in Example 2 was carried out except that tris 1,3,5-benzenetricarboxylic acid (2,3-dimethylcyclohexylamide (amide compound 3)) was used instead of the amide compound 1 as the amide compound. A resin molded product and a polypropylene-based resin foam molded product were obtained. The β crystal content, foaming ratio, bending strength, and specific strength were measured using the obtained polypropylene-based resin molded product and polypropylene-based resin foam molded product. The obtained results are summarized in Table 1. Further, as a result of confirming the formation state of acicular crystals of the amide compound and the β crystal content in the molded product in the same manner as in Example 1, the amide compound was fine. The formation of acicular crystals was confirmed, and the β crystal content of 80% or more was confirmed.

[Example 7]
The polypropylene-based resin molded product and polypropylene were carried out in the same manner as in Example 2 except that 1,3,5-benzenetricarboxylic acid triscyclooctylamide (amide compound 4) was used instead of the amide compound 1 as the amide compound. A based resin foam molded product was obtained. The β crystal content, foaming ratio, bending strength, and specific strength were measured using the obtained polypropylene-based resin molded product and polypropylene-based resin foam molded product. The results obtained are summarized in Table 1. Further, as a result of confirming the formation state of needle-like crystals of the amide compound and the β crystal content in the molded product in the same manner as in Example 1, the formation of fine needle-like crystals of the amide compound was confirmed, and 80% or more. The β crystal content was confirmed.

[Example 8]
The polypropylene-based resin molded product and the polypropylene-based resin foam molding were carried out in the same manner as in Example 2 except that 1,4-benzenedicarboxylic acid dicyclohexylamide (amide compound 5) was used instead of the amide compound 1 as the amide compound. I got a body. The β crystal content, foaming ratio, bending strength, and specific strength were measured using the obtained polypropylene-based resin molded product and polypropylene-based resin foam molded product. The results obtained are summarized in Table 1. Further, as a result of confirming the formation state of needle-like crystals of the amide compound and the β crystal content in the molded product in the same manner as in Example 1, the formation of fine needle-like crystals of the amide compound was confirmed, and 80% or more. The β crystal content was confirmed.

[Example 9]
Polypropylene resin molding was carried out in the same manner as in Example 1 except that the heating temperature of 280 ° C. during melt mixing in step (i) was changed to 200 ° C. and the heating temperature of 280 ° C. during molding product production was changed to 200 ° C. A product and a polypropylene-based resin foam molded product were obtained. The β crystal content, expansion ratio, bending strength, and specific strength were measured using the obtained polypropylene-based molded product and polypropylene-based resin foam molded product. The results obtained are summarized in Table 1. Further, as a result of confirming the formation state of acicular crystals of the amide compound and the β crystal content in the molded product in the same manner as in Example 1, the β crystal content was 80% or more, but the acicular compound was acicular. Regarding the state of crystal formation, it was confirmed that fine needle-like crystals were also formed, but more massive amide compounds were present.

[Comparative Example 1]
A polypropylene-based resin molded product and a polypropylene-based resin foam molded product were obtained in the same manner as in Example 3 except that the amide compound was not added. However, the obtained foamed molded product had poor foamability and did not reach a predetermined foaming ratio, which was 1.1 times. The foaming ratio, bending strength, and specific strength were measured using the obtained polypropylene-based molded product and polypropylene-based resin foam molded product. The results obtained are summarized in Table 1.

[Comparative Example 2]
A polypropylene-based resin molded product and a polypropylene-based resin foam molded product were obtained in the same manner as in Example 4 except that the amide compound was not added. The foaming ratio, bending strength, and specific strength were measured using the obtained polypropylene-based molded product and polypropylene-based resin foam molded product. The results obtained are summarized in Table 1.

[Reference value]
Using the polypropylene-based resin molded product obtained in Example 1, the bending strength and the specific strength were measured in the same manner as in the foam molded product without carrying out the foam manufacturing step (step iii)). The results obtained are shown in Table 1.

[Example 10]
100 parts by weight of polypropylene homopolymer (MFR = 10 g / 10 minutes (load 2160 g, temperature 230 ° C.), melting point; 168 ° C.) as polypropylene resin, 2,6-naphthalenedicarboxylic acid dicyclohexylamide (amide compound 1) 0 as amide compound .2 parts by weight, and 0.05 parts by weight of calcium stearate (manufactured by Nitto Kasei Kogyo Co., Ltd., trade name "Ca-St") as other additives, tetrakis [methylene-3- (3,5-di-tert) -Butyl-4-hydroxyphenyl) propionate] methane (manufactured by Ciba Specialty Chemicals, trade name "IRGANOX1010") 0.05 parts by weight, tetrakis (2,4-di-tert-butylphenyl) phosphite (Ciba Specialty) 0.05 parts by weight of Chemicals (trade name "IRGAFOS168")) was dry-blended. The dry blend was melt-mixed at a heating temperature of 280 ° C. using a twin-screw extruder (L / D = 45, manufactured by Technobel Co., Ltd.) and a screw diameter of 15 mm to dissolve the amide compound, and the extruded strand was produced. The polypropylene-based resin composition was prepared by cooling and cutting with a pelletizer. Then, 4 parts of the obtained polypropylene-based resin composition and sodium hydrogen carbonate-based foaming agent master batch (Polyslen EE205A manufactured by Eiwa Kasei Kogyo Co., Ltd.) were dried. The mixture was blended, melt-mixed at a resin temperature of 200 ° C. using a T-die extruder, extruded into a sheet, and cooled and solidified with a chill roll having a surface temperature of 120 ° C. to obtain a polypropylene foam molded product having a thickness of 200 μm. The bending strength was measured using the polypropylene-based resin foam molded product. The obtained results are shown in Table 2. Further, the needle-like shape of the amide compound in the polypropylene-based resin composition by the method (1) above. As a result of confirming the β crystal content in the crystal formation state by the method (2), the formation of fine needle-like crystals of the amide compound was confirmed, and the β crystal content of 80% or more was confirmed.

[Example 11]
Polypropylene resin foam molding was carried out in the same manner as in Example 9 except that 0.2 parts by weight of the amide compound was changed to 0.05 parts by weight and the heating temperature of 280 ° C. during melt mixing was changed to 260 ° C. I got a body. The bending strength was measured using the obtained polypropylene-based resin foam molded product. The results obtained are shown in Table 2. Further, as a result of confirming the formation state of needle-like crystals of the amide compound in the polypropylene-based resin composition by the method (1) above and the β crystal content by the method (2), the fine needle-like shape of the amide compound was confirmed. The formation of crystals was confirmed, and the β crystal content of 80% or more was confirmed.

[Comparative Example 3]
A polypropylene-based resin foam molded product was obtained in the same manner as in Example 11 except that the amide compound was not added. The bending strength was measured using the obtained polypropylene-based resin foam molded product. The results obtained are shown in Table 2.

From the results in Tables 1 and 2 above, the following can be seen. Comparing the results of (a) Example and Comparative Example, it can be seen that the foaming characteristics are remarkably improved and the mechanical properties are greatly improved by blending the amide compound of the present invention. It is presumed that this result is due to the nuclear agent effect of the amide compound of the present invention. (B) Furthermore, from the results of Examples 1 to 8, it is possible to further improve the mechanical strength of the obtained foamed molded product by forming the contained amide compound into fine needle-like crystals. I understand. From this result, it is presumed that the fine needle-like crystals of the amide compound of the present invention control the orientation of the polypropylene-based resin in the foam molding process. From the above results, it was confirmed that a polypropylene-based resin foam molded product having high foaming and high strength, which could not be achieved conventionally, can be easily obtained by applying the present invention.

INDUSTRIAL APPLICABILITY According to the present invention, in the production of a polypropylene-based resin foam molded product, high foaming is possible while maintaining the original excellent characteristics of the polypropylene-based resin foam molded product, and the strength of the obtained polypropylene-based resin foam molded product is further increased. Improvements have become possible, and polypropylene-based resin foam molded products can be applied to various applications more than ever before. In addition, high foaming without impairing mechanical properties is expected to reduce weight, resources, and energy, and is expected to expand applications in the fields of automobiles and electricity. Furthermore, even in the use of heat insulating materials, high foaming further enhances the heat insulating effect and is expected to contribute to energy saving.

Claims (15)

A polypropylene-based resin containing needle-like crystals of at least one amide compound selected from the group consisting of the amide compound represented by the following general formula (1) and the amide compound represented by the general formula (2). Foam molded product.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, fatty radicals of saturated or unsaturated 5 to 30 carbon atoms, alicyclic groups or aromatic having 6 to 30 carbon atoms having 5 to 30 carbon atoms Represents a group . ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ] The polypropylene-based resin foam molded product according to claim 1, wherein the amide compound is at least one amide compound represented by the following general formula (3).
[In formula (3), R ⁷ is a saturated or unsaturated aliphatic dicarboxylic acid residue having 2 to 18 carbon atoms, a saturated or unsaturated alicyclic dicarboxylic acid residue having 3 to 18 carbon atoms, or a carbon. Representing aromatic dicarboxylic acid residues of numbers 6-18, R ⁸ and R ⁹ represent the same or different cycloalkyl groups having 5 to 18 carbon atoms, respectively. ] (I) A polypropylene resin and at least one amide compound selected from the group consisting of the amide compound represented by the following general formula (1) and the amide compound represented by the general formula (2) at a temperature of 240 to 330 ° C. A step of heating to a range, melting and mixing, and dissolving the amide compound in the melted polypropylene resin,
(Ii) A step of cooling the molten polypropylene-based resin composition obtained in step (i) to a temperature of 80 ° C. or lower and precipitating acicular crystals of an amide compound in the solidified polypropylene-based resin composition.
(Iii) The polypropylene-based resin composition obtained in step (ii) is characterized by comprising a foam molding step of mixing a foaming agent, heating and mixing in a temperature range of 190 to 260 ° C., and then foaming. A method for producing a polypropylene-based resin foam molded article.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, fatty radicals of saturated or unsaturated 5 to 30 carbon atoms, alicyclic groups or aromatic having 6 to 30 carbon atoms having 5 to 30 carbon atoms Represents a group . ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ] (I) A polypropylene resin and at least one amide compound selected from the group consisting of the amide compound represented by the following general formula (1) and the amide compound represented by the general formula (2) are melt-mixed and then cooled and solidified. Then, the polypropylene-based resin composition obtained in the steps (ii) and (i) of producing the polypropylene-based resin composition containing the amide compound was heated to a temperature range of 240 to 330 ° C. and melted. A step of dissolving an amide compound in a resin and then cooling it to a temperature of 80 ° C. or lower to form a molded product having a predetermined shape containing acicular crystals of the amide compound.
(Iii) A polypropylene-based resin comprising a foam molding step of heating the molded product obtained in step (ii) to a temperature range of 150 to 240 ° C., injecting a foaming agent, and then foaming. A method for manufacturing a foam molded product.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, fatty radicals of saturated or unsaturated 5 to 30 carbon atoms, alicyclic groups or aromatic having 6 to 30 carbon atoms having 5 to 30 carbon atoms Represents a group . ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ] The production method according to claim 4, wherein the foaming agent is an inert gas in a supercritical state. The production method according to claim 5, wherein the inert gas is carbon dioxide. The production method according to any one of claims 3 to 6, wherein the foaming ratio in the foam molding step is 1.2 to 100 times. A polypropylene-based resin containing needle-like crystals of at least one amide compound selected from the group consisting of the amide compound represented by the following general formula (1) and the amide compound represented by the general formula (2). A polypropylene-based resin composition for producing a foamed molded product.
[In the formula, n represents an integer of 2 to 6. R ¹ is a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic polycarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. Represents a group. 2-6 ^{R 2} are the same or different, respectively, fatty radicals of saturated or unsaturated 5 to 30 carbon atoms, alicyclic groups or aromatic having 6 to 30 carbon atoms having 5 to 30 carbon atoms Represents a group . ]
[In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ may have the same or different hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and a substituent having 5 to 20 carbon atoms, respectively. Represents a cycloalkyl group or an aryl group which may have a substituent having 6 to 20 carbon atoms. Note that R ³ and R ⁴ and R ⁵ and R ⁶ do not represent hydrogen atoms at the same time, respectively. Further, R ³ and R ⁴ or R ⁵ and R ⁶ may be bonded to each other to form an alkylene group. ] The polypropylene-based resin composition for producing a polypropylene-based resin foam molded article according to claim 8, wherein the amide compound is at least one amide compound represented by the following general formula (3).
[In formula (3), R ⁷ is a saturated or unsaturated aliphatic dicarboxylic acid residue having 2 to 18 carbon atoms, a saturated or unsaturated alicyclic dicarboxylic acid residue having 3 to 18 carbon atoms, or a carbon. Representing aromatic dicarboxylic acid residues of numbers 6-18, R ⁸ and R ⁹ represent the same or different cycloalkyl groups having 5 to 18 carbon atoms, respectively. ] In the general formula (3), R ⁷ is a saturated or unsaturated aliphatic dicarboxylic acid residue having 3 to 12 carbon atoms, a saturated or unsaturated aliphatic dicarboxylic acid residue having 6 to 10 carbon atoms, or a carbon number of carbon atoms. The production of a polypropylene-based resin foam molded product according to claim 9, which represents 6 to 18 aromatic dicarboxylic acid residues, and R ⁸ and R ⁹ represent the same or different cycloalkyl groups having 5 to 12 carbon atoms, respectively. Polypropylene-based resin composition for. In the general formula (3), R ⁷ is the general formula (e).
The polypropylene-based resin composition for producing a polypropylene-based resin foam molded product according to claim 10, wherein the aromatic dicarboxylic acid residue represented by the above, and R ⁸ and R ⁹ are cyclohexyl groups. The polypropylene-based resin composition for producing a polypropylene-based resin foam molded product according to claim 11, wherein the amide compound is 2,6-naphthalenedicarboxylic acid dicyclohexylamide. The polypropylene-based resin composition for producing a polypropylene-based resin foam molded article according to claim 8, wherein the amide compound is at least one amide compound represented by the following general formula (4).
[In the formula, R ¹⁴ is a saturated or unsaturated aliphatic tricarboxylic acid residue having 2 to 18 carbon atoms, an alicyclic tricarboxylic acid residue having 3 to 18 carbon atoms, or an aromatic tricarboxylic acid having 6 to 18 carbon atoms. Represents a residue. Three ^{R 15} are the same or different, respectively, fatty radicals of saturated or unsaturated 5 to 30 carbon atoms, an alicyclic radical or an aromatic group having 6 to 30 carbon atoms having 5 to 30 carbon atoms Represent. ] The polypropylene-based resin composition for producing a polypropylene-based resin foam molded product according to claim 13, wherein the amide compound is at least one amide compound represented by the following general formula (5).
[In the formula, R ¹⁶ , R ¹⁷ , and R ¹⁸ are the same or different, and are represented by the following general formula (f), which are linear or branched alkyl or alkenyl groups or phenyl groups having 5 to 20 carbon atoms. Represents the cycloalkyl group to be formed. ]
[In the formula, x represents an integer of 1-8. ] The polypropylene resin composition for producing a polypropylene resin foam molded product according to any one of claims 8 to 14, wherein the melt flow rate of the polypropylene resin at 230 ° C. and a load of 2160 g is 0.1 to 60.0 g / 10 minutes. Stuff.