JP5703249B2 - Polyamide resin foam sheet and method for producing the same - Google Patents

Description

The present invention relates to a polyamide-based resin foam sheet and a method for producing the same.

Polyamide resins are widely used because they are tough and superior in wear resistance, lubricity, chemical resistance, and oil resistance compared to other general resins.
In particular, the polyamide 11 resin is a plant derived from a castor oil or the like, which is a monomer derived from castor oil as a raw material, and has recently become commercially available. The polyamide 11 resin has attracted attention as a resin capable of forming an environmentally friendly product.

By the way, in general, a polyamide-based resin is a crystalline resin, and therefore has a property of rapidly decreasing the melt viscosity in the vicinity of the melting point of the crystal, and it is difficult to express a viscosity suitable for foaming. It is difficult to form.
The polyamide 11 resin is no exception, and the following Patent Document 1 (paragraph 0027) describes that a rod-shaped foam molded article is formed by extrusion foaming by containing a compound having a carboxylic anhydride group. However, it is difficult to form a sheet-like foam.
On the other hand, as a method for obtaining a sheet-like polyamide resin foam, a compound having three or more carboxylic acid anhydride groups in one molecule, such as glycerol tris anhydro trimellitate, as a cross-linking agent in Patent Document 2 below. And a method using a copolymer of an α, β-unsaturated carboxylic acid anhydride such as maleic anhydride and styrene and / or an olefin. However, in the described method, polyamide 6 having a lower strength than polyamide 11 and polyamide 6,6 and amorphous polyamide can be preferably used among polyamide resins, but in the case of polyamide 11, the melt tension is increased by crosslinking. Is increased at the same time, and as a result, ductility is impaired, and it is difficult to obtain a sheet-like foam.

That is, it is difficult to form a polyamide resin foam sheet containing a polyamide 11 resin by extrusion foaming from a circular die or a flat die into a sheet shape such as a polystyrene resin foam sheet or a polypropylene resin foam sheet. It has become.
Therefore, conventionally, it has been difficult to easily obtain an environment-friendly polyamide resin foam sheet by a relatively simple method such as extrusion foaming.

Japanese Patent Publication No. 07-076285 Japanese Patent No. 3524006

  An object of the present invention is to provide a method for producing a polyamide-based resin foamed sheet, which can produce a polyamide-based resin foamed sheet containing a polyamide 11 resin by extrusion foaming. It is an object of the present invention to provide a polyamide-based resin foam sheet that is easy to manufacture while containing 11 resin.

  In order to solve the above-mentioned problems, the present inventors diligently studied. As a result, a polyamide resin 11 containing a block copolymer resin having a polyether block and a polyamide block in a certain ratio with respect to the polyamide 11 resin. As a result, it has been found that a melting characteristic suitable for extrusion foaming can be imparted, and the present invention has been completed.

  That is, the present invention relating to a method for producing a polyamide-based resin foam sheet for solving the above-mentioned problems includes a block copolymer resin having a polyether block and a polyamide block, and a polyamide 11 resin, and the polyamide 11 resin. A resin composition containing 1 to 45 parts by mass of the block copolymer resin with respect to 100 parts by mass is extruded and foamed into a sheet shape.

  Further, the present invention related to a polyamide-based resin foam sheet for solving the above problems includes a block copolymer resin having a polyether block and a polyamide block, and a polyamide 11 resin, and 100 parts by mass of the polyamide 11 resin. The block copolymer resin is contained in an amount of 1 to 45 parts by mass.

According to the present invention, when a resin composition containing a polyamide 11 resin is extruded and foamed into a sheet form from a flat die, a circular die or the like, a block copolymer resin having a polyether block and a polyamide block is used as the polyamide 11 resin. In a predetermined ratio.
From this, the melt characteristics of the resin composition containing these can be made suitable for extrusion foaming, and a polyamide-based resin foam sheet having a good foamed state can be obtained.

Embodiments according to the manufacturing method of the present invention will be described below.
In the method for producing a polyamide-based resin foam sheet of the present embodiment, a block copolymer resin (B) having a polyamide 11 resin (A) as a main component and further having a polyether block and a polyamide block, for foaming The resin composition containing the component (C) and various additives (D) is melt-kneaded in an extruder equipped with a die such as a circular die or a flat die, and extruded and foamed from the die into a sheet. Let
First, the material for forming the polyamide resin foam sheet will be described below.

(A) Polyamide 11 resin As the polyamide 11 resin, a resin obtained by ring-opening polycondensation of undecane lactam marketed under a trade name such as “nylon 11” or “rilsan” can be used.
In recent years, a polycondensate of 11-aminoundecanoic acid produced using castor oil has been commercially available as a polyamide 11 resin. In obtaining an environmentally friendly polyamide-based resin foam sheet, It is preferable to employ polyamide 11 resin derived from castor oil.
The polyamide 11 resin derived from castor oil may be a combination of 11-aminoundecanoic acid obtained from castor oil and 11-aminoundecanoic acid obtained from petroleum.
Further, in the present embodiment, it is not necessary to use a single variety of polyamide 11 resin. For example, polyamide 11 resin derived from castor oil and other plant-derived polyamide 11 resin and petroleum-derived polyamide 11 resin are mixed. May be used.
However, as the polyamide-based resin foam sheet according to the present embodiment, since the plant degree measured based on ASTM D6866 is preferably 5% or more, the total with the block copolymer resin (B). It is preferable to select the polyamide 11 resin so that the plant degree is 5% or more.

(B) Block Copolymer Resin The block copolymer resin is a copolymer resin having a polyether block serving as a soft segment and a polyamide block serving as a hard segment, and the polyether constituting the soft segment. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.
Specific examples of polyamides constituting the hard segment include polycondensation polyamides such as ε-caprolactam, 11-aminoundecanoic acid, 12-aminolauric acid, adipic acid, sebacic acid, terephthalic acid, isophthalic acid, and the like. Examples thereof include copolycondensation polyamides of dicarboxylic acids and diamines such as hexamethylenediamine, nonanediamine, and methylpentadiamine.

Among them, for the same reason as described for the polyamide 11 resin, as the block copolymer resin, a plant-derived resin in which 11-aminoundecanoic acid obtained from castor oil is used for forming a polyamide block is used. It is preferable to adopt.
That is, it can be said that it is preferable to use a block copolymer resin derived from castor oil in obtaining an environmentally friendly polyamide resin foam sheet.
Further, since the block copolymer resin in which the hard segment is formed of a polycondensate of 11-aminoundecanoic acid has a polyamide block portion having substantially the same structure as the polyamide 11 resin, the block copolymer resin It can also be said that it is preferable in that the compatibility between the resin and the polyamide 11 resin can be improved.

When the ratio of the block copolymer resin to the polyamide 11 resin is too small, the polyamide-based resin foam sheet is easily broken when a resin composition containing these is extruded and foamed into a sheet. It becomes difficult to obtain good products.
On the other hand, if the block copolymer resin is excessively contained, the melt viscosity of the resin composition becomes too high, and it becomes difficult to form a good foamed state at the time of extrusion foaming. May cause overcurrent in the motor.

  That is, the block copolymer resin not only makes the melt properties of the resin composition such as melt viscosity and melt tension suitable for extrusion foaming, but is suitable for the polyamide resin foam sheet after extrusion foaming. It is effective for imparting toughness and ductility, and it is important that the ratio with respect to 100 parts by mass of the polyamide 11 resin is 1 part by mass or more and 45 parts by mass or less, and 5 parts by mass or more and 30 parts by mass or less. It is preferable.

In the block copolymer resin, the durometer D hardness (ISO868) varies depending on the ratio of the hard segment and the soft segment, and the value of the durometer D hardness increases as the ratio of the polyamide block increases.
The melt characteristics of the resin composition and the mechanical characteristics of the polyamide-based resin foam sheet are also affected by the proportion of the soft segment in the block copolymer resin. Therefore, the block copolymer resin is specified in ISO868. The durometer D preferably contains a soft segment so that the hardness is 30 or more and 65 or less.

In general, when the melting point of a resin is measured by differential scanning calorimetry (DSC) or the like, the resin whose melting point peak is observed broader is closer to the melting point than the resin whose melting point peak is observed sharply. The characteristic change with respect to the temperature change becomes small.
That is, it can be said that the broader melting point peak as the mixed resin of the polyamide 11 resin and the block copolymer resin is advantageous in stably performing the extrusion foaming.
Therefore, as the block copolymer resin, for example, a resin whose melting point observed in the DSC method of JIS K7112 (temperature increase rate: 10 ° C./min) is 5 ° C. to 55 ° C. lower than that of the polyamide 11 resin. It is preferable to adopt.

  In addition, it is not necessary to use this block copolymer resin individually by 1 type, You may make it mix in multiple things and make it contain in the said resin composition.

(C) Component for foaming Examples of the component for foaming the resin as described above include a foaming agent (C1) and a cell nucleating agent (C2).

(C1) Foaming agent As the foaming agent, the same foaming agent as used in extrusion foaming of general resins such as polystyrene resins and polypropylene resins can be employed. For example, propane, norma Hydrocarbons such as lower alkanes such as rubbutane, isobutane, normal pentane, isopentane and hexane, ketones such as acetone, methyl ethyl ketone and acetylacetone, ethers such as dimethyl ether, halogenated hydrocarbons such as methyl chloride and ethyl chloride, dioxide Physical foaming agents such as inorganic gases such as carbon, nitrogen and air can be mentioned. Among these, normal butane, isobutane, dimethyl ether, and carbon dioxide are preferable. As the foaming agent, in addition to the above physical foaming agent, a chemical foaming agent, or a physical foaming agent and a chemical foaming agent may be used in combination.
As addition amount of a foaming agent, 0.5-10 mass parts is preferable with respect to 100 mass parts of resin components.

(C2) Cell nucleating agent As the cell nucleating agent, those generally used can be adopted, for example, talc, mica, silica, diatomaceous earth, alumina, titanium oxide, zinc oxide, magnesium oxide, hydroxylation. Inorganic compounds such as magnesium, aluminum hydroxide, calcium hydroxide, potassium carbonate, calcium carbonate, magnesium carbonate, potassium sulfate, barium sulfate, sodium bicarbonate, glass beads; polytetrafluoroethylene, azodicarbonamide, sodium bicarbonate and citric acid Examples include organic compounds such as acid mixtures, inert gases such as nitrogen, and talc is preferred.
In addition, a bubble nucleating agent may be used individually by 1 type, or may mix and use 2 or more types.
The addition amount of the cell nucleating agent is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the resin component.

(D) Additives As the additives, those conventionally used for processing thermoplastic resins may be appropriately included as necessary. For example, weathering stabilizers, light stabilizers, pigments, dyes , Flame retardants, crystal nucleating agents, plasticizers, lubricants, surfactants, dispersants, ultraviolet absorbers, antioxidants, fillers, reinforcing agents, antistatic agents, and the like.

For these materials, for example, everything except the foaming agent mixed at a predetermined blending ratio is melt-kneaded and granulated. Once a full compound is produced, it is supplied to an extruder and extruded and foamed. Alternatively, a dry blend may be simply supplied to the extruder and melt-kneaded in the extruder.
The foaming agent may be press-fitted in the middle of the extruder, and the kneaded material melt-kneaded after the foaming agent press-fit is adjusted to have a temperature suitable for extrusion foaming (for example, 200 ° C to 230 ° C). Then, it may be extruded and foamed into a sheet form from a circular die or a flat die attached to the tip of the extruder.

In the case of using a circular die, a foam (polyamide resin foam sheet) extruded in a sheet form from an annular discharge port is formed into a cylindrical shape connected in a round shape. By cutting continuously along the line, a flat strip-like polyamide resin foam sheet similar to that obtained by extrusion foaming from a flat die can be obtained.
At this time, if necessary, a plurality of strip-like polyamide-based resin foam sheets can be formed in a plurality of locations in the circumferential direction, for example, a cylindrical shape extruded and foamed from an annular discharge port of a circular die. The foam is stretched in the circumferential direction along the outer peripheral surface of the cooling mandrel larger than the diameter of the circular die and cooled, and the left and right sides of the foam after cooling are provided on the rear side of the cooling mandrel. Two strip-shaped polyamide resin foam sheets having a width that is half the circumference of the cooling mandrel can be produced by one extrusion foaming by cutting at two locations in the circumferential direction with a pair of cutting blades.

In addition, it is preferable to use a circular die for manufacturing the polyamide-based resin foam sheet.
This is because a flat die requires a special apparatus for stretching in a direction orthogonal to the extrusion direction, and both side portions may be wasted.
As described above, the circular die can be easily stretched in the direction perpendicular to the extrusion direction by using a cooling mandrel having a diameter larger than the diameter of the circular die.
In this embodiment, since the tension and elongation of the foam during extrusion foaming are improved, the ratio between the diameter of the cooling mandrel and the diameter of the circular die (also referred to as blow-up ratio) is 1.5 or more. Sheets can be manufactured.
If the blow-up ratio is small, the resulting polyamide-based resin foam sheet has a directionality, which is not preferable.
In this embodiment, it can be stably manufactured with a blow-up ratio of 2.0 to 3.5.

In the extrusion foaming, for example, a non-foamable resin composition is coextruded with a foamable resin composition containing the foaming agent to contain a polyamide 11 resin and a block copolymer resin. A polyamide-based resin foam sheet may be formed as a laminated foam sheet having a foam layer and a non-foam layer made of another resin.
That is, the polyamide-based resin foam sheet in this embodiment is not necessarily a single foam layer, and a laminate product of a foam layer and a non-foam layer, a laminate product having a plurality of foam layers, and the like of the present invention are also included. As intended.

In this embodiment, unlike the methods described in Japanese Patent Publication No. 07-076285 and Japanese Patent No. 3524006, a block copolymer composed of a soft segment and a hard segment is used instead of controlling the melt tension by a crosslinking reaction. A polyamide-based resin foam sheet having excellent quality can be obtained by using a resin.
When producing an extruded foam sheet by performing a crosslinking reaction, there is an advantage that the melt tension can be controlled within the molecule, but on the other hand, since the molecular chains are fixed by the crosslinking reaction, the fluidity of the resin is lowered and the resulting foam sheet is obtained. The ductility of the steel may decrease.
Further, with the decrease in ductility, there is a possibility that the cushioning property, which is an excellent feature of the foamed sheet, may be impaired.
In the case of a crosslinking reaction, since the reaction is carried out in the extruder, it is necessary to control the residence time (residence time) of the resin during extrusion, and if the residence time becomes too long, the crosslinking reaction proceeds too much. As a result, the load applied to the extruder during extrusion may become excessive.

When a resin having high rigidity such as polyamide 11 resin is controlled to a melt tension suitable for extrusion foaming by a crosslinking reaction and an extruded foam sheet is to be obtained, the load on the extruder may be increased. It is preferable to extrude while suppressing, but when the discharge amount is suppressed, it is not easy to control the melt tension suitable for extrusion foaming because the crosslinking reaction may proceed excessively.
Therefore, in this embodiment, the melt tension is not controlled by the crosslinking reaction, and a block copolymer resin composed of soft segments and hard segments rich in elasticity is included.
Therefore, the obtained polyamide resin foam sheet can be expected to have high buffering properties, and it is not necessary to control the residence time of the polyamide resin in the extruder during extrusion, and the shear rate can be controlled by changing the discharge amount. Since it can do, control of a foaming factor and a basic weight becomes easy.

As a polyamide resin foam sheet formed by extrusion foaming using a polyamide resin blended with a block copolymer resin composed of a soft segment and a hard segment in this manner, a foamed layer alone is usually used. it can thickness 0.5 mm to 2.0 mm, a basis weight of 100g / m ² ~650g / m ² to.
Conventionally, when a polyamide-based resin foam sheet having a polyamide 11 resin as a main component at a blow-up ratio as described above is manufactured, the polyamide-based resin foam sheet is likely to break due to the tension and stretching force applied during the manufacture. However, in this embodiment, the block copolymer resin is used in combination with the polyamide 11 resin to suppress the breakage of the sheet when produced at the blow-up ratio as described above. Can be manufactured stably.
Further, by blending the castor oil-derived polyamide 11 and the block copolymer to produce a polyamide-based resin foam sheet, the planting degree according to the blending ratio, the plant degree of the polyamide 11 and the plant degree of the block copolymer A polyamide-based resin foam sheet having the following can be obtained.

  That is, in the present embodiment, by using the block copolymer resin together with the polyamide 11 resin, a polyamide-based resin foam sheet containing the polyamide 11 resin can be efficiently produced by extrusion foaming. Since a resin derived from castor oil can be employed as a copolymer resin, an environment-friendly polyamide-based resin foam sheet can be easily produced.

In other words, it includes a block copolymer resin having a polyether block and a polyamide block, and a polyamide 11 resin, and the block copolymer resin is 1 part by mass or more and 45 parts by mass with respect to 100 parts by mass of the polyamide 11 resin. The polyamide-based resin foam sheet contained in an amount of less than or equal to part by mass can be produced by a production method excellent in productivity called extrusion foaming.
In particular, when the block copolymer resin contains ISO 868 having a specified durometer D hardness of 30 or more and 65 or less, it becomes easier to manufacture.
Particularly, a polyamide-based resin foam in which at least a part of the block copolymer resin and the polyamide 11 resin is castor oil-derived resin so that the plant degree measured based on ASTM D6866 is 5% or more. The sheet can be used for various applications as an environmentally friendly plastic material.

  According to the technical matter found by the present inventor, not only the polyamide 11 resin but also the polyamide 12 resin obtained by ring-opening polymerization of lauryl lactam or the like, the block copolymer having a polyether block and a polyamide block is used. For example, by containing a polymer resin in an amount of 1 part by mass or more and 45 parts by mass or less with respect to 100 parts by mass of polyamide 12 resin, a polyamide-based resin foam sheet in a favorable foamed state can be formed by a simple technique called extrusion foaming. it can.

  Although not described in detail here, even if there are matters that are not directly described above, conventionally known matters as the technical matters relating to the polyamide-based resin foam sheet do not significantly impair the effects of the present invention. This can be adopted in the range.

EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these.
(Example 1)
Polyamide 11 resin (manufactured by Arkema, trade name “Rilsan”, grade name “BESN 0 TL”) was dried at a temperature of 100 ° C. for 4 hours using a dehumidifying dryer.
This dried polyamide 11 resin and block copolymer resin (trade name “PebaxRnew 40R53 SP01” manufactured by Arkema, which is a block copolymer resin having a polyether block and a polyamide block) and talc (manufactured by Nippon Talc, The product name “Micro Ace”) was mixed with a tumbler mixer so that the ratio with respect to 100 parts by mass of polyamide 11 resin was 5.2 parts by mass of block copolymer resin and 1.0 part by mass of talc.

Next, the mixture obtained by the above mixing is supplied to a hopper of a single screw extruder (caliber 65 mm, L / D30), melted and kneaded, and butane having a ratio of 2.0 parts by mass with respect to 100 parts by mass of the polyamide 11 resin. (Foaming agent) was press-fitted from the middle of the extruder, and further melted and kneaded.
Then, extrusion foaming was performed from a circular die having a diameter of 80 mm provided at the tip of the extruder and an annular outlet gap of 0.40 mm so that the resin temperature during extrusion was 210 ° C.
A cylindrical polyamide resin foam sheet extruded and foamed from a circular die is cut open after being expanded along a cylindrical cooling mandrel (with a diameter of 205 mm and a length of 400 mm) in which cooling water is circulated. And formed into a strip shape having a width of 640 mm and wound into a roll. (Blow-up ratio 2.6)
The polyamide-based resin foam sheet wound up in the form of a roll had an expansion ratio of 3 times, a thickness of 0.7 mm, and an open cell ratio of 67%.
Various physical properties of the obtained polyamide resin foam sheet (Example 1) are shown in Table 1 below.

In addition, the "tensile test" in Table 1 is based on JIS K7127-1999 foamed plastic-polyethylene-testing method, with Tensilon universal testing machine UCT-10T (manufactured by Orientec Co., Ltd.), with a test speed of 100 mm / min. It is measured using test piece type 5 (0.7 mm).
Further, the tear test was conducted in accordance with JIS K6767-1999 foamed plastic-polyethylene-testing method using a Tensilon universal testing machine UCT-10T (manufactured by Orientec Co., Ltd.) with a test speed of 500 mm / min and a b-type (crescent type). ) Measured using a test piece.
Further, “MD” in Table 1 represents that the test piece was collected and measured so that the extrusion direction was the longitudinal direction, and “TD” was a test piece whose width direction perpendicular to the extrusion direction was the test piece. It shows that it measured so that it might become the longitudinal direction of (1).
Further, the “dynatap impact test” in Table 1 is a value measured by a Dynatap impact test apparatus GRC 8250 (manufactured by General Research Corp) based on ASTM D3763.

  Moreover, the following item was evaluated about the polyamide 11 resin and block copolymer resin which were used for the polyamide-type resin foam sheet.

(Plant degree)
The plant degree (biomass degree) of the polyamide 11 resin and the block copolymer resin was measured according to ASTM D6866.

(density)
The density of the polyamide 11 resin and the block copolymer resin was measured by the A method (underwater substitution method) defined in JIS K7112: 1999 “Plastics—Method of measuring density and specific gravity of non-foamed plastic”.

(Melting point)
The melting point was measured by the method described in JIS K7122: 1987 “Method for measuring the transition heat of plastic”.
That is, using a differential scanning calorimeter RDC220 type (manufactured by Seiko Denshi Kogyo Co., Ltd.), about 7 mg of a sample is filled in a measuring container, and a nitrogen gas flow rate is 30 ml / min. The temperature was raised, lowered, and raised repeatedly at the rate of temperature rise and fall of min, and the melting peak temperature of the DSC curve at the second temperature rise was taken as the melting point.
When there are two or more melting peaks, the lower peak temperature is taken as the melting point.

(Durometer D hardness)
The durometer D hardness was measured as an instantaneous value according to the ISO868 standard.

  Further, the open cell ratio and strain at the time of tensile fracture of the polyamide resin foam sheet were measured as follows.

(Open cell ratio)
Collect multiple test pieces of 25 x 25 mm square from a polyamide resin foam sheet and stack them up to a thickness of about 30 mm. As a measuring instrument, “Aya, Comparison, Pycnometer, Model made by Tokyo Science Co., Ltd.” 1000 ”, the true volume Vx was measured by the air pycnometer method of ASTM D2856, and the open cell ratio was calculated according to the following formula.
Open cell ratio (%) = (Va−Vx) / Va × 100
(However, Va is an apparent volume (cm ³ ) obtained from the outer dimension of the measurement sample, and Vx is a true volume (cm ³ ) of the measurement sample.)

(Strain at tensile failure)
Based on the test method described in JIS K 7127-1999, the measurement was performed as follows. A test piece type 5 (thickness 0.7 mm) test piece is set in a tensile tester (chuck interval is 50 mm), pulled at a speed of 100 mm / min, and the elongation rate when cut is defined as the strain at tensile fracture. As a tensile testing machine, what is marketed by the brand name "Tensilon universal testing machine UCT-10T" from Orientic, for example can be used.
The results are shown in Table 2 below.

(Examples 2 to 5, Comparative Examples 1 and 2)
In the same manner as in Example 1, an evaluation study was carried out on the method for producing a polyamide resin foam sheet of each example and comparative example.
the detail is right below.

(Example 2)
A polyamide-based resin foam sheet was prepared in the same manner as in Example 1 except that the ratio of the block copolymer resin (PebaxRnew 40R53 SP 01) to 100 parts by mass of the polyamide 11 resin (BESN 0 TL) was 43 parts by mass. It was.
Extrusion foaming was good, and the obtained polyamide resin foam sheet had a width of 640 mm, a foam multiple of 3 times, a thickness of 0.7 mm, and an open cell ratio of 64%.

(Example 3)
A polyamide-based resin foam sheet was produced in the same manner as in Example 1 except that the resin temperature during extrusion was adjusted to 200 ° C.
Extrusion foaming was good, and the obtained polyamide-based resin foam sheet had a width of 640 mm, a foam multiple of 3 times, a thickness of 0.7 mm, and an open cell ratio of 29%.

Example 4
The block copolymer resin is made of another grade (manufactured by Arkema, product surface “PebaxRnew 55R53 SP 01”), and the ratio to 100 parts by mass of polyamide 11 resin (BESN 0 TL) is 11 parts by mass. A polyamide-based resin foam sheet was prepared in the same manner as in Example 1 except that the resin temperature at that time was 215 ° C.
Extrusion foaming was good, and the obtained polyamide resin foam sheet had a width of 640 mm, a foam multiple of 3 times, a thickness of 0.7 mm, and an open cell ratio of 55%.

(Example 5)
The block copolymer resin is made of another grade (manufactured by Arkema, product surface “PebaxRnew 35R53 SP 01”), and the ratio to 100 parts by mass of polyamide 11 resin (BESN 0 TL) is 11 parts by mass. A polyamide-based resin foam sheet was prepared in the same manner as in Example 1 except that the resin temperature at that time was 205 ° C.
Extrusion foaming was good, and the obtained polyamide-based resin foam sheet had a width of 640 mm, a foam multiple of 3 times, a thickness of 0.7 mm, and an open cell ratio of 48%.

(Comparative Example 1)
A polyamide-based resin foam sheet was prepared in the same manner as in Example 1 except that the block copolymer resin was not contained.
However, the foam from the circular die was hardly foamed and was not of a level that could be called a foam sheet.

(Comparative Example 2)
3.3 parts by mass of a styrene-maleic anhydride copolymer (manufactured by Elf Atchem, trade name “SMA3000”) per 100 parts by mass of polyamide 11 resin, and the resin temperature at the time of extrusion was 220 ° C. Except for the above, a foamed sheet was produced in the same manner as in Comparative Example 1.
In Comparative Example 2, extrusion foaming was possible, but the polyamide-based resin foam sheet was apt to break, and good take-out could not be performed on the extruded foam.
That is, the one extruded from the circular die does not have an elongation or tension that shows followability to take-up, and it is difficult to take it along the cooling mandrel.

(Reference Example 1)
A polyamide-based resin foam sheet was prepared in the same manner as in Example 1 by containing 67 parts by mass of a block copolymer resin (PebaxRnew 40R53 SP 01) with respect to 100 parts by mass of a polyamide 11 resin (BESN 0 TL). The extrusion load was high and extrusion foaming could not be performed.

(Reference Example 2)
The block copolymer resin was replaced with the trade name “PebaxRnew 40R53 SP 01” having a durometer D hardness of 42, and the product name “PebaxRnew 72R53 SP 01” having a durometer D hardness of 71 was used in the same manner as in Example 2. When an attempt was made to produce a polyamide-based resin foam sheet, the load on the extruder was high and extrusion foaming could not be performed.
However, in Reference Example 2, a good polyamide-based resin foam sheet could be obtained by reducing the extrusion amount to about 60% of Example 1 and increasing the resin temperature during extrusion foaming.

(Reference Example 3)
When a polyamide-based resin foam sheet was produced in the same manner as in Example 1 using a polyamide 12 resin (trade name “L25”, manufactured by EMS Japan Co., Ltd.) instead of the polyamide 11 resin, it was as good as in Example 1. I was able to get the product.
The obtained foam was a sheet having a width of 640 mm, the expansion ratio was 3 times, the thickness was 0.7 mm, and the open cell ratio was 62%.

  The above results are shown in Tables 3 and 4 below.

As described above, according to the present invention, a polyamide resin foam sheet having good quality can be produced by extrusion foaming by using a block copolymer resin having a polyether block and a polyamide block together with a polyamide 11 resin. I understand.
In particular, it can also be seen from the above results that a block copolymer resin having a predetermined hardness is advantageous.
In addition, as can be seen from the reference examples, the present invention is suitable in the case of polyamide 11 which is a resin derived from castor oil, because it is possible to obtain an environmentally friendly foamed sheet. Of course, a polyamide other than polyamide 11 such as polyamide 12 is used. It can be seen that using a block copolymer resin having a polyether block and a polyamide block in combination with the resin is effective in forming a polyamide-based resin foam sheet by extrusion foaming.

Claims (6)

  A block copolymer resin having a polyether block and a polyamide block, and a polyamide 11 resin are contained, and the block copolymer resin is contained in an amount of 1 to 45 parts by mass with respect to 100 parts by mass of the polyamide 11 resin. A method for producing a polyamide-based resin foam sheet, which comprises extruding and foaming a resin composition in a sheet shape.   The method for producing a polyamide-based resin foam sheet according to claim 1, wherein the block copolymer resin has a durometer D hardness of 30 or more and 65 or less as defined in ISO868.   Of the block copolymer resin and the polyamide 11 resin used in the production of the polyamide resin foam sheet, at least a part of the resin is derived from castor oil, and the degree of vegetableity measured based on ASTM D6866 is 5% or more. The manufacturing method of the polyamide-type resin foam sheet of Claim 1 or 2 which produces a foam sheet.   A block copolymer resin having a polyether block and a polyamide block, and a polyamide 11 resin are contained, and the block copolymer resin is contained in an amount of 1 to 45 parts by mass with respect to 100 parts by mass of the polyamide 11 resin. A polyamide resin foam sheet characterized by having   The polyamide-based resin foam sheet according to claim 4, wherein the block copolymer resin has a durometer D hardness of 30 or more and 65 or less as defined in ISO868.   6. The polyamide system according to claim 4 or 5, wherein a plant degree measured based on ASTM D6866 is 5% or more, and at least a part of the block copolymer resin and the polyamide 11 resin is a resin derived from castor oil. Resin foam sheet.