JP2000318078A - Liquid crystal polymer reinforced foam and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal polymer reinforced foam consisting of a thermoplastic resin, excellent in dimensional stability such as the coefficient of linear expansion or the like and bending strength, and a method for producing the same. SOLUTION: A foamed sheet with a foaming magnification of 5 times or less is laminated on at least the single surface of a foam substrate comprising a thermoplastic resin and this foamed sheet comprises a composite wherein a fibrillated liquid polymer is dispersed in a thermoplastic resin in an unidirectionally oriented state or a composite wherein a fibrillated liquid polymer is dispersed in a thermoplastic resin in a three-dimensionally random state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal polymer reinforced foam and a method for producing the same, and more particularly, to a liquid crystal polymer reinforced foam used for interior materials for automobiles and building materials, and a method for producing the same.

[0002]

2. Description of the Related Art Thermoplastic resin foams have excellent heat insulating properties, light weight and cushioning properties, and are used in a wide range of materials such as interior materials for house building materials, heat insulating materials for hot water supply pipes, and automobile parts such as bumpers and interior materials. It is used for various applications. As the thermoplastic resin foam, for example, in JP-A-8-325404,
A polyolefin having excellent heat resistance and flexibility is disclosed. Such resin foams are used for various applications. Among them, there are applications requiring dimensional stability, such as a roof insulation material of a building and an automobile interior.

[0003] Although the above-mentioned thermoplastic resin foam is improved in dimensional stability by cross-linking, it is basically greatly deformed above the softening point of the matrix. In some cases, the sex was not enough. In addition, there is a disadvantage that the bending strength rapidly decreases with an increase in the expansion ratio.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a foam made of a thermoplastic resin, which has excellent dimensional stability such as linear expansion coefficient and excellent bending strength, and its production. It is to provide a method.

[0005]

The liquid crystal polymer reinforced foam according to the first aspect of the present invention (hereinafter referred to as the first invention) has an expansion ratio of at least one side of a foam base material made of a thermoplastic resin. A liquid crystal polymer reinforced foam in which foam sheets having a thickness of not more than 1 times are laminated, and the foam sheet is a composite (I) in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in a state of being unidirectionally oriented, or A fibril-like liquid crystal polymer is three-dimensionally and randomly dispersed in a thermoplastic resin (II).

The liquid crystal polymer reinforced foam according to the invention described in claim 2 of the present application (hereinafter, referred to as a second invention) is 70 to 9
A liquid crystal polymer reinforced foam in which a foam sheet having an expansion ratio of 5 or less is laminated on at least one surface of a foam base material composed of 9% by weight of a thermoplastic resin and 30 to 1% by weight of a fibril-like liquid crystal polymer, The composite sheet (I) in which the foamed sheet is a fibril-like liquid crystal polymer dispersed in a thermoplastic resin in a state of being oriented in one direction, or the fibril-like liquid crystal polymer is three-dimensionally random in a thermoplastic resin. Characterized by comprising a complex (II) dispersed by:

[0007] In the method for producing a liquid crystal polymer reinforced foam according to the invention described in claim 3 of the present application (hereinafter referred to as a third invention), a resin composition comprising a thermoplastic resin and a liquid crystal polymer is melt-kneaded in an extruder. After dissolving the physical foaming agent that exhibits a gaseous state at normal temperature and normal pressure under high pressure, at least one surface of a foam base material obtained by discharging and foaming from a mold, a fibril-like material in a thermoplastic resin Characterized in that they are laminated and integrated with a foamed sheet having a foaming ratio of 5 or less in which the liquid crystal polymer is dispersed in one direction.

The liquid crystal polymer reinforced foam according to the invention described in claim 4 of the present application (hereinafter, referred to as a fourth invention) comprises a thermoplastic resin and a fibril-like liquid crystal formed on at least one surface of a foam base made of a thermoplastic resin. A liquid crystal polymer reinforced foam in which a thermoplastic resin sheet made of a polymer is laminated, and the thermoplastic resin sheet is dispersed in a thermoplastic resin in a state where most of the fibril-like liquid crystal polymer is oriented in one direction. The liquid crystal polymer comprises a complex (III) dispersed in a state where a part of the liquid crystal polymer is oriented in different directions.

Hereinafter, the first invention will be described. The liquid crystal polymer reinforced foam of the first invention is formed from a foam base material made of a thermoplastic resin and a foam sheet laminated on at least one surface.

The thermoplastic resin is not particularly limited as long as it can be foamed. Examples thereof include polyethylene (which may be any of high density, low density and linear low density), and polypropylene. (Homopolymer, block copolymer, random copolymer may be any), polybutylene, ethylene-vinyl acetate copolymer,
Examples include polyvinyl acetate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, and polycarbonate.

The melt index (MI) of the thermoplastic resin is preferably in the range of 0.1 to 15 g / 10 minutes, and more preferably 0.1 to 15 g / 10 minutes, because the foamability is reduced if the melt index is too large or too small. The range is 2 to 10 g / 10 minutes. The MI is a value measured according to JIS K7210.

The above-mentioned thermoplastic resin may be cross-linked, if necessary. By being cross-linked,
Since the foaming ratio of the obtained foam is improved, the weight can be reduced, and the thermal stability is also improved.

[0013] The crosslinking method is not particularly limited.
For example, an electron beam crosslinking method of irradiating an ionizing radiation such as an electron beam; a chemical crosslinking method using an organic peroxide; a silane crosslinking method using a silane-modified resin, and the like can be given.

The higher the degree of crosslinking of the thermoplastic resin, the lower the expansion ratio and the lower the flexibility, and the lower the degree of cross-linking, the lower the thermal stability, and the cells break during foaming, making it impossible to obtain uniform cells. Therefore, the gel fraction as an index of the degree of crosslinking is preferably 10 to 50%, more preferably 10 to 35%.

The gel fraction is a value obtained by expressing the weight of the residue after immersing the crosslinked thermoplastic resin in xylene at 120 ° C. for 24 hours with respect to the weight before immersion in xylene. It is calculated by the formula. Gel fraction (%) = [(residue weight of thermoplastic resin after immersion in xylene) / (weight of thermoplastic resin before immersion in xylene)] × 100

The elongational viscosity required for foaming the thermoplastic resin is 8,000 to 30,000 at 210 ° C.
Poise is preferred, more preferably 10,000 to 27
0.00 poise, more preferably 12,000
~ 25,000 poise. The elongational viscosity is 8.0
If it is lower than 00 poise, the resin breaks during foaming and foam breaks occur. If it is higher than 30,000 poise, the elongation stress is too high and the elongation of the resin is insufficient. Disappears. The elongational viscosity is a value measured according to JIS K 7117.

In order to obtain a foam base material made of the thermoplastic resin, a method of foaming using a conventionally known foaming agent is employed. When using a thermal decomposition type foaming agent as the foaming agent, for example, after melting and kneading the thermoplastic resin and the thermal decomposition type foaming agent below the decomposition temperature of the foaming agent, heating to above the decomposition temperature of the foaming agent A foaming method may be used.

The pyrolytic foaming agent is not particularly limited as long as it has a decomposition temperature higher than the melting temperature of the thermoplastic resin used. Examples thereof include sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, and azide compound. Thermal decomposition type foaming agents such as sodium and sodium borohydride; azodicarbonamide, azobisisobutyronitrile, N,
N'-dinitrosopentamethylenetetramine, P, P '
-Dinitrosopentamethylenetetramine, P, P'-oxybisbenzenesulfonylhydrazilo, barium azodicarboxylate, and organic pyrolytic foaming agents such as trihydrazinotriazine. Of these, azodicarbonamide, which is easy to adjust the decomposition temperature and decomposition rate, generates a large amount of gas, and is excellent in hygiene, is preferable.

The amount of the thermal decomposition type foaming agent is preferably 1 to 20 parts by weight based on 100 parts by weight of a mixture of the thermoplastic resin and a liquid crystal resin described later. If the addition amount is less than 1 part by weight, foaming is insufficient and a foamed cell structure is not formed. If the addition amount is more than 20 parts by weight, the foaming pressure at the time of foaming exceeds the elongation stress of the thermoplastic resin. Therefore, a high-strength foam cannot be obtained.

The foamed sheet to be laminated on at least one surface of the foamed base material made of the thermoplastic resin includes a composite (I) in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in a state of being unidirectionally oriented. Alternatively, a composite (II) in which fibril-like liquid crystal polymers are randomly dispersed three-dimensionally in a thermoplastic resin is used.

Examples of the thermoplastic resin used for the foamed sheet include the same thermoplastic resins used for the foamed base material. The combination of the thermoplastic resin used for the foam base material and the foamed sheet preferably has adhesiveness when laminated, and for this purpose, a combination of polar polymers and a combination of nonpolar polymers are preferable. .

The liquid crystal polymer is not particularly limited as long as it has a liquid crystal transition temperature higher than the melting point of the thermoplastic resin.
Thermoplastic liquid crystal polyesters such as semi-aromatic polyesters and thermoplastic polyesteramides are preferred. Commercially available products of the wholly aromatic polyester-based liquid crystal polymer and semi-aromatic polyester-based liquid crystal polymer include, for example, "Vectra" (trade name) manufactured by Polyplastics, "Sumitoka Super" (trade name) manufactured by Sumitomo Chemical Co., Ltd. "Zyder" manufactured by Nippon Petrochemical Co., Ltd.
(Trade name) and "Rod Run" (trade name) manufactured by Unitika Ltd. and the like.

The above-mentioned liquid crystal polymer has a property of being easily oriented in the flow direction when given an elongational flow at a temperature higher than the liquid crystal transition point due to its molecular structure. That is, after the mixture of the thermoplastic resin and the liquid crystal polymer is melt-kneaded at a temperature equal to or higher than the liquid crystal transition point of the liquid crystal polymer, and extruded while giving elongation, the liquid crystal polymer becomes a fibril in the thermoplastic resin serving as a matrix. And a reinforcing effect is exhibited.

The apparent elongation rate required to convert the above liquid crystal polymer into fibrils in a thermoplastic resin matrix is preferably from 1 × 10 ^-1 to 1 × 10 ³ / sec, more preferably 3 × 10 ^-1. １1 × 10 ² / sec. When the apparent elongation rate is out of the above range, the liquid crystal polymer in the mixture is unlikely to be in the form of fibrils.

The aspect ratio of the fibril-like liquid crystal polymer in the thermoplastic resin matrix is 50 to 50.
The range of 5,000 is preferred, and more preferably 100 to
It is in the range of 3,000. When the aspect ratio is less than 50, the reinforcing effect of the liquid crystal polymer on the foamed sheet is reduced. When the aspect ratio is more than 5,000, the foaming property of the resin matrix is reduced and the expansion ratio is not increased. In addition, it becomes difficult to obtain a liquid crystal polymer reinforced foam having excellent dimensional stability.

In order to obtain a composite (I) in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin matrix in a unidirectional orientation as the foamed sheet, the thermoplastic resin and the liquid crystal polymer are melt-kneaded. Thereafter, the obtained melt-kneaded product is stretched while being foamed while applying the above-mentioned elongation speed, whereby the liquid crystal polymer is fibrillated to be oriented in one direction; the melt-kneaded product of the thermoplastic resin and the liquid crystal polymer is stretched. A method of fibrillating by stretching while applying a speed, orienting in one direction, and then foaming may be used, and any method may be employed.

The final stretching ratio of the composite (I) is 5
It is preferably in the range of up to 50 times. When the stretching ratio is less than 5 times, the elastic strength of the fibril-like liquid crystal polymer is small, so that the bending strength of the obtained liquid crystal polymer reinforced foam is low. On the other hand, when the stretching ratio exceeds 50 times, the fibril-like liquid crystal polymer once formed is broken, and thus cannot be used as a reinforcing material for a thermoplastic resin. Here, the stretching ratio is expressed by: (cross-sectional area of fibril-like liquid crystal polymer before stretching) / (cross-sectional area of fibril-like liquid crystal polymer after stretching).

In order to form the composite (I) into a sheet,
For example, there is a method in which a melt-kneaded material discharged from a T-die attached to a tip of an extruder is passed between a pair of cooling rolls having a predetermined clearance to be formed into a constant thickness. It is preferable that the clearance between the cooling rolls is set to be 0.2 to 0.5 mm smaller than a predetermined thickness. If the clearance is less than 0.2 mm from the predetermined thickness, the surface smoothness of the obtained unfoamed sheet is reduced, and if it exceeds 0.5 mm from the predetermined thickness, the unfoamed sheet becomes thinner than the predetermined thickness.

In the case where the unfoamed sheet is subjected to electron beam crosslinking or silane crosslinking, a treatment according to a crosslinking method is carried out during or after the step of molding the melt-kneaded product of the thermoplastic resin and the liquid crystal polymer into a sheet. Should be applied.

The above two methods are used properly depending on the kind of the foaming agent to be used, and the method is preferably applied when a physical foaming agent which exhibits a gaseous state at normal temperature and normal pressure is used as the foaming agent. It is preferably applied when a mold blowing agent is used.

In the above-mentioned method, a physical foaming agent is impregnated and dissolved in a melt-kneaded product of the thermoplastic resin and the liquid crystal polymer, then released under normal pressure, and foamed by the expansion force of the physical foaming agent. After elongating in the melted state while foaming and fibrillating, the foamed sheet is obtained by shaping at a temperature not lower than the melting temperature of the thermoplastic resin and not lower than the liquid crystal transition point of the liquid crystal polymer.

Examples of the physical foaming agent include carbon dioxide, nitrogen, chlorofluorocarbon and the like. The amount of the physical foaming agent dissolved in the melt-kneaded product is determined according to the expansion ratio of the foam sheet. In the melt-kneading of the thermoplastic resin and the liquid crystal polymer, it is preferable to use a single-screw or twin-screw extruder in order to increase the degree of kneading and foamability.

In the above method, the thermoplastic resin, the liquid crystal polymer and the pyrolytic foaming agent are heated to a temperature not lower than the melting temperature of the thermoplastic resin, not lower than the liquid crystal transition point of the liquid crystal polymer and not higher than the decomposition temperature of the pyrolytic foaming agent. After melt-kneading at, fibrillation is performed by stretching at the above elongation speed. Then, after forming into a sheet at a temperature above the melting temperature of the thermoplastic resin and below the liquid crystal transition point of the liquid crystal resin,
The obtained unfoamed sheet is foamed by heating it to a temperature higher than the decomposition temperature of the pyrolytic foaming agent. Examples of the thermal decomposition type foaming agent used here include the same thermal decomposition type foaming agents as those used in the foam base material, but those having a decomposition temperature equal to or higher than the liquid crystal transition point of the liquid crystal polymer are preferable. .

As the heating method, a method of introducing the unfoamed sheet into a heating furnace in which the inside is maintained at a temperature not lower than the decomposition temperature of the pyrolytic foaming agent; a method of blowing hot air onto the unfoamed sheet; For example, a method of immersing a foamed sheet in an oil bath and heating the foamed sheet to a temperature equal to or higher than the decomposition temperature of the pyrolytic foaming agent can be used.

As a cooling method of the heated and foamed sheet, for example, a method of blowing cold air; a method of passing between opposed rolls whose temperature is controlled to be equal to or lower than the melting temperature of the thermoplastic resin; a method of immersing in cold water It is preferable to cool the thermoplastic resin to a temperature not higher than the melting temperature of the thermoplastic resin.

The expansion ratio of the foam sheet laminated on at least one side of the foam base material is 5 times or less. If the expansion ratio exceeds 5 times, the strength is rapidly reduced, and the effect of laminating the foamed sheet is lost.

The method of laminating the foam base material and the foam sheet is not particularly limited.
Examples thereof include a method using a hot melt adhesive.

Next, the composite (II) in which the fibril-like liquid crystal polymer is three-dimensionally dispersed in a random state in the thermoplastic resin used as the foamed sheet will be described.

The composite (II) is prepared by blending a thermoplastic resin and a liquid crystal polymer by a general method, and melt-kneading the mixture at a temperature equal to or higher than the transition point of the liquid crystal polymer. It is obtained by cooling to a temperature below the melting temperature of the thermoplastic resin while taking off as described above. At this stage, the liquid crystal polymer changes from a particulate state to a fibril state in the thermoplastic resin, and reinforces the thermoplastic resin. The method of melt-kneading is not particularly limited, but it is preferable to use a twin-screw extruder from the viewpoint of high kneading degree.

In order to obtain a foam sheet from the composite (II), a method similar to that for the composite (I) is employed.

Next, the second invention will be described. In the second invention, a foam in which a thermoplastic resin is three-dimensionally reinforced by a fibril-like liquid crystal polymer is used as the foam base material.

The same thermoplastic resin and liquid crystal polymer as those of the first invention are used. The mixing ratio of both is 30 to 1% by weight of the liquid crystal polymer to 70 to 99% by weight of the thermoplastic resin. From the viewpoint of increasing the strength of the foam, the mixing ratio of the thermoplastic resin and the liquid crystal polymer is limited to the above range.

That is, if the ratio of the liquid crystal polymer is less than 1% by weight, the bending strength of the obtained liquid crystal polymer reinforced foam is not sufficient, and if it is more than 30% by weight, the fibril-like liquid crystal polymer is expanded during the expansion. Breaks through to break through. Since the closed cell ratio is reduced by the foam breaking, the bending strength of the obtained liquid crystal polymer reinforced foam is reduced. In addition, the closed cell rate is a value obtained by dividing the volume of the foaming gas trapped in the cells among the bubbles existing in the foam by the total foaming gas amount present in the foam, and is expressed as a percentage. is there.

Next, a method for producing the upper foam base material will be described. Thermoplastic resin and liquid crystal polymer are blended by a general method and melt-kneaded at a temperature higher than the melting temperature of the thermoplastic resin and higher than the liquid crystal transition point of the liquid crystal polymer, and the elongation required for fibrillation of the liquid crystal polymer is obtained. After stretching at a speed, it is cooled. The elongation rate is preferably in the same range as in the first invention.

A pyrolytic foaming agent is added to the mixture of the thermoplastic resin and the liquid crystal polymer cooled above, and the mixture is melt-kneaded again at a temperature not lower than the melting temperature of the thermoplastic resin and not higher than the liquid crystal transition point of the liquid crystal polymer. Then, it is shaped into a sheet and cooled. Crosslinking may be performed to increase the expansion ratio.
Crosslinking is performed by a general method, and for example, chemical crosslinking using an organic peroxide; electron beam crosslinking using an electron beam; silane crosslinking using a silane-modified resin can be used.

The foamable sheet comprising the thermoplastic resin, the liquid crystal polymer and the pyrolytic foaming agent obtained by the above method is used to decompose the thermoplastic resin at a temperature higher than the melting temperature of the thermoplastic resin and lower than the liquid crystal transition point of the liquid crystal polymer. By heating to a temperature equal to or higher than the temperature to cause foaming and then cooling, a foam base material made of a thermoplastic resin and a fibril-like liquid crystal polymer is obtained. At this time, the method of heating or cooling is not particularly limited.

The expansion ratio of the foam base material is set to 5 times or less for the same reason as in the first invention.

The liquid crystal polymer reinforced foam of the second invention is obtained by laminating a foam sheet on at least one surface of a foam base comprising the thermoplastic resin and the liquid crystal polymer. As the foam sheet, the same foam sheet as in the first invention is used, and the foam base material and the foam sheet are laminated by the same method as in the first invention.

Next, the third invention will be described. In the method for producing a liquid crystal polymer reinforced foam according to the third invention, a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in at least one surface of a foam base material in a unidirectionally oriented state. By laminating and integrating the foam sheets, a liquid crystal polymer reinforced foam is obtained.

The above-mentioned foam base material is prepared by dissolving a physical foaming agent which exhibits a gaseous state at normal temperature and normal pressure under high pressure in a state where a mixture obtained by blending a thermoplastic resin and a liquid crystal polymer is melt-kneaded in an extruder. Then, it is obtained by discharging and foaming from a mold. When a mixture in which a physical foaming agent is dissolved under high pressure is discharged under normal pressure, the physical foaming agent undergoes a state change from a liquid to a gas, and foams to form a foam base material. At this time, when the same elongation rate as that of the first invention is applied to the mixture, elongation deformation of the mixture occurs, and the liquid crystal polymer is fibrillated to reinforce the foam base material obtained.

As the above-mentioned thermoplastic resin and liquid crystal polymer, those similar to those of the first invention are used. The physical foaming agent is in a gaseous state at normal temperature and normal pressure, and the same as in the first invention is used.

A foam sheet having a foaming ratio of 5 times or less in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in one direction is laminated on at least one surface of the foam substrate, and pressing force is applied. To be integrated. As the foamed sheet, the same one as the composite (I) of the first invention is used.

For laminating the foamed sheet and the foamed substrate made of the thermoplastic resin and the liquid crystal polymer, for example,
A method using heat fusion, a method using a hot melt adhesive, and the like are used. In the above foam sheet, since the fibril-like liquid crystal polymer is particularly oriented on the surface portion of the thermoplastic resin, the foam base material is in a molten state, and continuous while many fibrils are protruding also on the surface. When the layers are laminated with a specific pressing force, an anchor effect is developed, so that the interfacial adhesive force is increased. Once the foam substrate is cooled, even if it is heated again, the amount of fibrils that jump out to the surface of the foam substrate decreases. Therefore, when the foam base and the foam sheet are heat-sealed, it is preferable to perform the lamination while the foam base is in a molten state.

The method of applying a pressing force at the time of lamination is not particularly limited, but it is preferable to pass between a pair of opposed rolls having a certain clearance since continuous production is possible. The pressing force when passing between the rolls is 0.5
The range is preferably from 5 kg / cm ^{2 to 5} kg / cm ² . The pressing force is 0.5
If less than kg / cm ² , sufficient adhesive strength cannot be obtained and 5 kg
If it exceeds / cm ² , the foam base material is deformed and the thickness becomes thin.

The temperature at which the foam substrate is pressed is the melting temperature of the thermoplastic resin in the foam plus (10 to 50 ° C.)
Is preferable. When the pressing temperature is lower than the above range, the adhesive strength decreases, and when the pressing temperature is higher than the above range, the orientation of the fibril-like liquid crystal polymer in one direction after lamination decreases, and the mechanical properties and dimensional stability decrease. Cooling after lamination is performed by a general method.

Next, the fourth invention will be described. The liquid crystal polymer reinforced foam of the fourth invention is formed by laminating a thermoplastic resin-based sheet made of a thermoplastic resin and a fibril-like liquid crystal polymer on at least one surface of a foam base made of a thermoplastic resin. .

As the foam base material made of the above-mentioned thermoplastic resin, the one made of the same thermoplastic resin as in the first invention can be used, but the one made of a thermoplastic resin and a liquid crystal polymer may be used. . When a foam base material made of a thermoplastic resin and a liquid crystal polymer is used, the thermoplastic resin 7 may be used for the same reason as in the second invention.
Those comprising 0 to 99% by weight and 30 to 1% by weight of a liquid crystal polymer are preferred. The same thermoplastic resin and liquid crystal polymer as in the first invention are used, and the foam base having the above composition can be obtained by the same method as in the second invention.

In the thermoplastic resin sheet, most of the fibril-like liquid crystal polymer is dispersed in the thermoplastic resin in a state of being oriented in one direction, and a part of the liquid crystal polymer is randomly dispersed in a direction different from the orientation direction. Complex (III) dispersed in a state of being oriented is used.

In the composite (III), it is preferable that a part of the fibril-like liquid crystal polymer is 10 to 50% of the entire fibril-like liquid crystal polymer. 10
%, The anisotropy of the thermoplastic resin sheet cannot be sufficiently eliminated, and if it exceeds 50%, the ratio of the orientation direction of the liquid crystal fibrils is not constant, so that the ratio increases. Dimensional stability and mechanical strength decrease.

The direction different from the above-mentioned orientation direction is not particularly limited, and is one clockwise from most fibril orientation directions.
Refers to an arbitrary direction of up to 180 degrees, preferably not a fixed angle to the orientation direction, for example, as shown in FIG.
Preferably they are oriented at any angle.

In the composite (III), the mixing ratio of the thermoplastic resin and the liquid crystal polymer is preferably 1 to 60 parts by weight of the liquid crystal polymer with respect to 100 parts by weight of the thermoplastic resin.
More preferably, it is 3 to 40 parts by weight. When the amount of the liquid crystal polymer is less than 1 part by weight, the effect of reinforcing the liquid crystal polymer is not sufficiently exhibited, and when the amount exceeds 60 parts by weight, the liquid crystal polymer cannot be uniformly dispersed in the thermoplastic resin.

In order to improve the compatibility between the thermoplastic resin and the liquid crystal polymer, a compatibilizer may be added before or during molding of the composite (III). As the compatibilizer, for example, when the thermoplastic resin is an olefin resin, a copolymer of an olefin component and a styrene component or an aromatic polyester component, an olefin resin having a maleic acid component and an olefin resin having a glycidyl methacrylate component A resin-based copolymer or the like is used. Further, a semi-aromatic liquid crystal resin may be used.

The amount of the compatibilizer used is appropriately determined depending on the mixing composition and the mixing ratio of the thermoplastic resin and the liquid crystal polymer.
0.1 to 5 parts by weight based on parts by weight is preferred. If the amount used is less than 0.1 part by weight, the compatibilizing effect is not sufficiently exhibited, and if it exceeds 5 parts by weight, the physical properties of the compatibilizer itself are easily reflected, and the mechanical properties of the composite (III) Causes a decline.

As a method of forming the composite (III), for example, a part of a strand extruded from a mold is
A method of traversing at a constant period in a direction perpendicular to the orientation direction of most strands is used. Specifically, a part of a large number of strands may be individually divided and traversed in the direction perpendicular to the alignment direction at a constant period and a constant width. For example, as shown in FIG. And a method of traversing a comb-like material having the above in a strand with an air cylinder or the like. The traverse width and period of the comb are not particularly limited as long as the strands extruded from the mold are integrated with most of the continuously oriented strands without being cut by the traverse.

The material of the comb is not particularly limited, but it is preferable that the surface of the comb does not have an adhesive property with the melt of the composite (III), and more preferably Cr plating or low surface resistance. Those coated with Teflon are preferred.

As a method of laminating the composite (III) and the foam base material, as in the first invention, for example, a method by heat fusion, a method using a hot melt adhesive, and the like can be mentioned.

(Function) The liquid crystal polymer reinforced foam of the present invention comprises a foam base material made of a thermoplastic resin and a foam sheet laminated on at least one surface. The foamed sheet is formed from a sheet-like material in which fibril-like liquid crystal polymers are oriented and dispersed in one direction, or a sheet-like material in which fibril-like liquid crystal polymers are randomly dispersed in a three-dimensional direction.

Since the above liquid crystal polymer has almost no elasticity in the alignment direction due to its molecular structure, if the fibril liquid crystal polymer is aligned and dispersed in one direction in a thermoplastic resin, a material having extremely excellent dimensional stability can be obtained. Becomes In addition, since the fibril-like liquid crystal polymer having a high elastic modulus is arranged in one direction, the reinforcing effect is maximum, and the composite comprising the thermoplastic resin and the liquid crystal polymer has extremely high mechanical strength. Further, in the case where the above-mentioned foamed sheet has a fibril-like liquid crystal polymer oriented and dispersed in a three-dimensional direction in a random state, since the three-dimensionally reinforced liquid crystal polymer is randomly strengthened, the anisotropy in strength and dimensional stability is reduced. Disappears.

In the liquid crystal polymer reinforced foam of the second invention,
The fibril-like liquid crystal polymer is dispersed and arranged in the thermoplastic foam base material, so that the cell walls of the foam base material are reinforced with the fibril-like liquid crystal polymer having a high elastic modulus, so that a high-rigidity foam is used. Becomes

In the manufacturing method of the third invention, the melt-kneaded product of the thermoplastic resin and the liquid crystal polymer is laminated and integrated with the thermoplastic foam base while being stretched, so that the liquid crystal polymer reinforced foam having excellent interfacial adhesion is obtained. It becomes possible to gain a body.

In the liquid crystal polymer reinforced foam of the fourth invention,
Most of the liquid crystal polymer fibrils are oriented in one direction in the thermoplastic resin, and a part of the liquid crystal polymer fibrils is oriented in a direction different from the orientation direction.
Because it is laminated and integrated with a thermoplastic resin foam base material,
It is possible to obtain a liquid crystal polymer reinforced foam in which anisotropy is eliminated and dimensional stability and mechanical properties are balanced.

Further, in the liquid crystal polymer reinforced foam of the fifth invention, the thermoplastic resin sheet used in the fourth invention is laminated with the thermoplastic foam base material in which the fibril-like liquid crystal polymer is dispersed and arranged. Therefore, the liquid crystal polymer reinforced foam in which the anisotropy is further eliminated and the dimensional stability and mechanical properties are balanced can be obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to embodiments.

Example 1 Polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: J-Aroma PS201A)
MI = 0.5 g / 10 min, density 0.90 g / cm ³ , melting temperature 165 ° C.) 3 kg, liquid crystal polymer (manufactured by Polyplastics, trade name: Vectra A950, density 1.40 g)
/ Cm ³ , liquid crystal transition point 285 ° C) 2 kg,
Twin screw kneading extruder (PCM-30, manufactured by Ikegai Kiko Co., Ltd.)
, And extruded through a 10-hole strand die having a diameter of 5 mm. At this time, the barrel temperature and the mold temperature of the extruder were both set to 290 ° C. The extruded mixture had a diameter of 7 mm, and was cooled by passing it between a pair of opposed rolls, which had been temperature-controlled by water cooling, while taking it to a diameter of 1.5 mm, and the liquid crystal polymer was oriented in one direction. To obtain a laminate expandable sheet. still,
The clearance between the rolls is 100 μm, and the obtained laminate foamable sheet has a width of 50 mm and a thickness of 150 μm.
Met. At this time, the take-off speed was 2 m / sec, and the apparent extension speed given to the mixture was 5 × 10 / sec.

Next, polypropylene (manufactured by Nippon Polychem Co., Ltd., trade name: MA3, MI = 10 g / 10 min, density: 0.1%)
3.5 kg of 90 g / cm ³ , melting temperature 165 ° C.), 1.5 kg of silane-modified polypropylene (manufactured by Mitsubishi Chemical Corporation, trade name: Linklon HPM800HM, MI = 10 g / 10 min, density 0.917 g / cm ³ ), silane 0.075 kg of a crosslinking catalyst (manufactured by Mitsubishi Chemical Corporation, trade name: PZ-10S),
And a pyrolytic foaming agent (trade name: Uniform AZ SO-20, manufactured by Otsuka Chemical Co., Ltd., decomposition temperature 201 ° C.) 0.5 k
g, and melt-kneaded with a twin-screw kneading extruder (trade name: PCM-30, manufactured by Ikegai Kiko Co., Ltd.), and then extruded from a sheet die having a width of 300 mm and a lip clearance of 3 mm,
The sheet was cooled and formed into a sheet by passing between a pair of water-cooled opposing rolls to obtain a foamable sheet for a substrate.

The obtained foamable sheet for base material having a thickness of 3 mm and a width of 250 mm was successively crosslinked with hot water at 100 ° C. for 2 hours. 2 crosslinked foamable sheets for substrate
After heating in an oven controlled at 20 ° C and foaming,
Air cooling was performed to obtain a flat polypropylene foam base material. The thickness of this foam base material was 8 mm, and the expansion ratio was 20 times. The expansion ratio was calculated from the density before and after foaming.

The above polypropylene foam base material and the foamable sheet for lamination are heated to 180 ° C. to be in a molten state, then they are laminated, and cooled while applying a pressing force. A liquid crystal polymer reinforced foam having the following (shown in FIG. 1) was obtained. The pressing force at this time was 1 kg / cm ² . 150 × from the obtained liquid crystal polymer reinforced foam
A sample for a bending test of 20 mm was cut out five by five in the orientation direction of the liquid crystal polymer and the direction perpendicular thereto, and the JIS
The bending strength was measured according to K7171 and is shown in Table 1.

Further, the linear expansion coefficients of the liquid crystal polymer reinforced foam in a direction parallel to and perpendicular to the orientation direction of the liquid crystal polymer were measured. The coefficient of linear expansion was measured by heating the foam from room temperature 23 ° C. to 100 ° C., and the value of the coefficient of linear expansion was calculated from the following equation. Linear expansion coefficient = (distance between marked lines after heating−distance between marked lines before heating) / (foam temperature after heating−foam temperature before heating)

Example 2 Polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: J-Aroma PS201A)
MI = 0.5 g / 10 min, density 0.90 g / cm ³ , melting temperature 165 ° C.) 3 kg, liquid crystal polymer (manufactured by Unitika Ltd., trade name: Rodrun LC-3000, density 1.40)
g / cm ³ , liquid crystal transition temperature 185 ° C.) 2 kg, and high-temperature decomposition type foaming agent (Otsuka Chemical Co., Ltd., trade name: ODH foaming agent, decomposition temperature 244 ° C.) 0.2 kg, and a twin-screw kneading extruder ( The mixture was melt-kneaded with Ikegai Kiko Co., Ltd., trade name PCM-30) and extruded from a 10-hole strand die having a diameter of 5 mm. At this time, the barrel temperature and the mold temperature of the extruder are
In each case, the temperature was set to 210 ° C. Although the extruded resin composition had a diameter of 6 mm, it was cooled and formed into a sheet by passing it between a pair of opposing rolls whose temperature was controlled by water cooling while taking the diameter to 1 mm. A foamable sheet was obtained.

The clearance between the rolls is 100 μm.
The obtained foamable sheet for lamination had a width of 50 mm and a thickness of 150 μm. The pick-up speed at this time is 1.5
m / sec, and the apparent elongation rate given to the laminate foamable sheet was 1 × 10 / sec. The obtained foamable sheet for lamination was heated and foamed using a heating furnace controlled at 260 ° C., and then air-cooled to obtain a flat foamed sheet.
The expansion ratio of this foam sheet was 2 times. Except for using the above foam sheet, a liquid crystal polymer reinforced foam was obtained in the same manner as in Example 1, and the obtained liquid crystal polymer reinforced foam was evaluated for performance in the same manner as in Example 1. The results are shown in Table 1. It was shown to.

(Example 3) Polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: J-Alomer PS201A)
3 kg and liquid crystal polymer (Polyplastics,
(Trade name: Vectra) 2 kg was blended, melt-kneaded with a twin-screw kneading extruder (trade name: PCM-30, manufactured by Ikegai Kiko Co., Ltd.), and extruded from a 10-hole strand die having a diameter of 5 mm. At this time, the barrel temperature and the mold temperature of the extruder were both set to 290 ° C. The extruded mixture is 7m in diameter
However, it was cooled to form a sheet by passing it between a pair of opposed rolls whose temperature was controlled by water cooling while taking it to a diameter of 1.5 mm to obtain a foamable sheet for lamination. The clearance between the rolls was 100 μm, and the obtained laminate foamable sheet had a width of 50 mm and a thickness of 150 μm. At this time, the take-up speed was 2 m / sec, and the apparent elongation speed given to the foamable sheet for lamination was 1 × 10 / sec.

Next, 3.5 k of polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: J-Alomer PS201A)
g, and 1.5 kg of a liquid crystal polymer (manufactured by Polyplastics, trade name: Vectra A950) are blended and melt-kneaded with a twin-screw kneading extruder (manufactured by Ikekai Kiko Co., Ltd., trade name: PCM-30) to obtain a 3 mm diameter. Extruded from a one-hole strand die. At this time, the barrel temperature and the mold temperature of the extruder were both set at 290 ° C. The extruded mixture is 4m in diameter
m, which was water-cooled while being taken up to a diameter of 0.7 mm to form a strand. At this time, the take-off speed was 3 m / sec and the apparent elongation speed given to the mixture was 3 × 10 / sec. The obtained strand was cut into a length of 3 mm and pelletized.

Subsequently, 3 kg of the above-mentioned 3 mm-long pellets,
0.9 kg of silane-modified polypropylene (manufactured by Mitsubishi Chemical Corporation, trade name: Wrinklon HPM800HM MI = 10 g / 10 min, density 0.917 g / cm ³ ), silane cross-linking catalyst master batch (manufactured by Mitsubishi Chemical Corporation, trade name: PZ-) 10S)
0.045 kg and 0.4 kg of a thermal decomposition type foaming agent (manufactured by Otsuka Chemical Co., trade name: Uniform AZ SO-20, decomposition temperature 201 ° C.) are blended, and a twin-screw kneading extruder (manufactured by Ikekai Kiko Co., Ltd.) After melt-kneading under the name PCM-30), the mixture was extruded from a sheet die having a width of 300 mm and a lip clearance of 3 mm, and then cooled and formed into a sheet by passing between a pair of water-cooled opposed rolls to obtain a foamable sheet for a substrate. Was. The obtained foamable sheet for base material is
The thickness was 3 mm and the width was 250 mm. The sheet was subsequently crosslinked with hot water at 100 ° C. for 2 hours.

The crosslinked foamable sheet for base material was
After heating in an oven controlled at 20 ° C and foaming,
Air cooling was performed to obtain a flat (liquid crystal polymer reinforced) polypropylene foam base material. This foam base material was a foam having a thickness of 8 mm and an expansion ratio of 20 times, in which cells were randomly reinforced in a three-dimensional direction with a fibril-like liquid crystal polymer.
The expansion ratio is obtained by dividing the density before foaming by the density after foaming. The above-mentioned foam base material and the foamable sheet for lamination are heated to 180 ° C. to be in a molten state, then both are laminated and cooled while applying a pressing force, and a liquid crystal polymer having foam sheets on both surfaces of the foam base material A reinforced foam (shown in FIG. 2) was obtained. The pressing force at this time was 1 kg / cm ² . The bending strength and linear expansion coefficient of this liquid crystal polymer reinforced foam were measured in the same manner as in Example 1, and are shown in Table 1.

Example 4 Polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: J-Aroma PS201A)
After blending 3.5 kg and 1.5 kg of a liquid crystal polymer (manufactured by Polyplastics, trade name: Vectra A950), a twin-screw kneading extruder (trade name: PCM, manufactured by Ikegai Kiko Co., Ltd.)
-30), and the mixture was extruded from a 1-hole strand die having a diameter of 3 mm. At this time, the barrel temperature and the mold temperature of the extruder were both set to 290 ° C. Although the extruded mixture had a diameter of 4 mm, the mixture was water-cooled while being taken up to a diameter of 0.7 mm to form a strand.
The take-up speed at this time was 3 m / sec, and the apparent elongation speed given to the mixture was 3 × 10 / sec. The obtained strand was cut into a length of 3 mm and pelletized.

The above pellets (3 kg) were melted and kneaded with a twin screw kneading extruder (trade name: PCM-30, manufactured by Ikegai Kiko Co., Ltd.).
After being extruded from a sheet die having a width of 100 mm and a lip clearance of 0.2 mm, the sheet was cooled and formed into a sheet by passing between a pair of water-cooled opposing rolls to obtain a sheet for lamination. The obtained sheet for lamination has a thickness of 150 μm and a width of 8
It was 0 mm. Since this sheet is obtained by remelting and kneading pellets in which the fibril-shaped liquid crystal polymer is oriented in one direction in polypropylene, the fibril-shaped liquid crystal polymer is randomly dispersed in the sheet in the three-dimensional direction. Was. Except for using this lamination sheet, a liquid crystal polymer reinforced foam (shown in FIG. 3) was obtained in the same manner as in Example 3, and the obtained liquid crystal polymer reinforced foam was evaluated for performance in the same manner as in Example 1. Table 1 shows the results.

(Example 5) Polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: J-Alomer PS201A)
3.5 kg and 1.5 kg of a liquid crystal polymer (manufactured by Polyplastics, trade name: Vectra A950) were blended, and 2
After melt-kneading with a shaft kneading extruder (trade name: PCM-30, manufactured by Ikegai Kiko Co., Ltd.), the mixture was extruded from a 1-hole strand die having a diameter of 3 mm. At this time, the barrel temperature and the mold temperature of the extruder were both set to 290 ° C. Although the extruded mixture had a diameter of 4 mm, the mixture was water-cooled while being taken up to a diameter of 0.7 mm to form a strand. The take-off speed at this time was 3 m / sec, and the apparent extension speed given to the mixture was 3 × 10 / sec. The obtained strand was cut into a length of 3 mm and pelletized.

Subsequently, 3 kg of the above-mentioned 3 mm-long pellets,
0.9 kg of silane-modified polypropylene (manufactured by Mitsubishi Chemical Corporation, trade name: Linklon HPM800HM), silane cross-linking catalyst master batch (manufactured by Mitsubishi Chemical Corporation, trade name: PZ-10)
S) 0.045 kg of a pyrolysis type foaming agent (manufactured by Otsuka Chemical Co., Ltd., trade name: Uniform AZ SO-20, decomposition temperature 201 ° C.) 0.04 kg, and a twin-screw kneading extruder (manufactured by Ikegai Kiko Co., Ltd.) Melt-kneaded under the trade name PCM-30), extruded from a sheet die having a width of 100 mm and a lip clearance of 0.5 mm, and cooled and formed into a sheet by passing between a pair of water-cooled opposed rolls. I got The obtained foamable sheet for lamination had a thickness of 750 μm and a width of 80 mm. At this time, the barrel temperature and the mold temperature of the extruder were both set at 180 ° C.

The above foamable sheet for lamination is continuously heated to 100 ° C.
For 1 hour with hot water. The crosslinked laminating foamable sheet was heated in an oven controlled at 220 ° C. to foam it, and then air cooled to obtain a flat (liquid crystal polymer reinforced polypropylene foam sheet). In this foam, the cells were three-dimensionally reinforced with a fibril-like liquid crystal polymer. The thickness of the foam sheet was 1.5 mm, and the expansion ratio was 2 times. Example 1 Using the Foam Sheet
In the same manner as in Example 1, a liquid crystal polymer reinforced foam (shown in FIG. 3) was obtained. The performance of the obtained liquid crystal polymer reinforced foam was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 6 Polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: J-Aroma PS201A)
3.5 kg and 1.5 kg of a liquid crystal polymer (manufactured by Polyplastics, trade name: Vectra A950) are blended, and a twin-screw extruder (trade name: PCM-3, manufactured by Ikegai Kiko Co., Ltd.)
The mixture was melt-kneaded in 0) and extruded from a 1-hole strand die having a diameter of 3 mm. The barrel temperature and the mold temperature of this extruder were both set to 290 ° C. Although the extruded mixture had a diameter of 4 mm, the mixture was water-cooled while being taken up to a diameter of 0.7 mm to form a strand. The take-off speed at this time was 3 m / sec, and the apparent extension speed given to this mixture was 3 × 10 / sec. The obtained strand was cut into a length of 3 mm and pelletized.

Subsequently, the pellets were melt-kneaded with a 65 mm single screw extruder (manufactured by Nagata Seisakusho). The temperature of both the barrel and the mold was set at 180 ° C., carbon dioxide was injected from the center of the barrel, and then the temperature of the barrel and the mold was gradually lowered to 170 ° C. A strand die having a diameter of 5 mm was used as a mold. After foaming started, the rod-shaped foam was cooled by passing between a pair of opposed rolls. The clearance between the rolls was adjusted to obtain a foam base material having a thickness of 5 mm and a width of 50 mm. When the expansion ratio of this foam base material is measured, it is 2
It was 0 times.

Next, the foamed sheet made of the polypropylene and the liquid crystal polymer of Example 1 was inserted from the extruder side of the pair of opposed rolls while adjusting the position so as to be laminated with the foamed base material. Was adjusted to 1.5 kg / cm ² to obtain a liquid crystal polymer reinforced foam having foam sheets on both surfaces of a foam substrate. The obtained foam was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Example 7 A mixture 100 composed of 40% by weight of a liquid crystal polymer (Vectra A950, manufactured by Polyplastics Co., Ltd.) and 60% by weight of a polypropylene resin (melting point: 165 ° C., melt index: 0.5 g / 10 minutes)
Dry blending of 4 parts by weight of a semi-aromatic liquid crystal polymer (manufactured by Unitika Ltd., trade name: Rodrun LC-3000) and 2 parts by weight of an acid-modified polypropylene resin (manufactured by Nippon Polyolefin Co., Ltd., trade name: Adtex ER320P) did. Next, this dry blend was supplied to a twin-screw kneading extruder (trade name: PCM-30, manufactured by Ikegai Kiko Co., Ltd.).
The mixture was melt-kneaded at 90 ° C., and a plurality of strands were extruded from a multi-hole strand die having a diameter of 3 mm and two rows of 15 holes.
As shown in FIG. 6, a part of the strand-like material immediately after the extrusion is divided into a comb-like material having a plurality of protrusions, and while being traversed at a constant period in a direction perpendicular to the orientation direction, two strands are formed. Pressure roll (roll clearance 100μ)
m, a pressure of 5 kg / cm ² , and a temperature of 20 ° C.).
m, a thermoplastic resin sheet having a width of 50 mm was obtained. The take-off speed at this time was 2 m / sec, and the apparent elongation speed given to the sheet was 5 × 10 / sec.

The thermoplastic resin sheet was broken, and the fracture surface was observed with a scanning electron microscope.
It was confirmed that most of the liquid crystal polymers were fibrillated and oriented in a certain direction, and that some of the liquid crystal polymers were oriented in a direction different from this orientation direction. A liquid crystal polymer reinforced foam was obtained in the same manner as in Example 1 except that this thermoplastic resin-based sheet was used instead of the foamable sheet for lamination, and the obtained liquid crystal polymer reinforced foam (schematic diagram in FIG. 7) Is evaluated) in the same manner as in Example 1, and the results are shown in Table 1.

(Example 8) A liquid crystal polymer reinforced foam was obtained and obtained in the same manner as in Example 3, except that the thermoplastic resin-based sheet of Example 7 was used instead of the foamable sheet for lamination. A liquid crystal polymer reinforced foam (schematic diagram is shown in FIG. 8) was evaluated for performance in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Example 1) Polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: J-Aroma PS201A)
5 kg of twin-screw kneading extruder (trade name: PCM, manufactured by Ikegai Kiko Co.
The mixture was melt-kneaded at −30) and extruded from a 10-hole strand die having a diameter of 5 mm. At this time, the barrel temperature and the mold temperature of the extruder were both set to 290 ° C. The extruded mixture had a diameter of 7 mm, which was
The sheet was cooled and formed into a sheet by passing between a pair of opposing rolls whose temperature was controlled by water cooling while being taken up to obtain a sheet for lamination. The clearance between the rolls at this time was 100 μm, and the obtained sheet had a width of 50 mm.
The thickness was 150 μm. The take-up speed at this time is 2 m /
And the apparent elongation rate provided to the polypropylene was 5 × 10 / sec. A liquid crystal polymer reinforced foam was obtained in the same manner as in Example 1, except that the above-mentioned laminating sheet was used. The obtained foam was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Example 2) 3 kg of polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: Jayromer), liquid crystal polymer (manufactured by Unitika, trade name: Rodrun LC-3)
000) 2 kg and a high-temperature decomposition type foaming agent (manufactured by Otsuka Chemical Co., Ltd., trade name: ODH blowing agent, decomposition temperature 244 ° C.) 2 kg
Was melt-kneaded with a twin-screw extruder (trade name: PCM-30, manufactured by Ikegai Kiko Co., Ltd.), and extruded from a 10-hole strand die having a diameter of 5 mm. The barrel temperature and the mold temperature of the extruder were both set to 210 ° C. Although the extruded mixture had a diameter of 6 mm, it was cooled and formed into a sheet by passing it between a pair of opposed rolls whose temperature was controlled by water cooling while taking this to a diameter of 1 mm. I got a sheet.

The clearance between the rolls was 100 μm, and the obtained foamable sheet for lamination had a width of 50 mm and a thickness of 150 μm. The take-up speed at this time is 1.5 m /
Second and the apparent extension rate given to the mixture is 1
× 10 / sec. The obtained foamable sheet for lamination was
The foam was heated and foamed using a heating furnace controlled at 60 ° C. to obtain a foamed sheet. The expansion ratio of this foam sheet was 20 times. Except for using this foamable sheet for lamination,
A liquid crystal polymer reinforced foam was obtained in the same manner as in Example 1.
The same evaluation as in Example 1 was performed on the obtained liquid crystal polymer reinforced foam, and the results are shown in Table 1.

(Comparative Example 3) Polypropylene (manufactured by Nippon Polyolefin Co., Ltd., trade name: J-Aroma PS201A)
2kg and liquid crystal polymer (made by Polyplastics,
3 kg of a trade name: VECTRA A950) was blended, melt-kneaded with a twin-screw kneading extruder (trade name: PCM-30, manufactured by Ikegai Kiko Co., Ltd.), and extruded from a 1-hole strand die having a diameter of 3 mm. Extruder barrel temperature and mold temperature were both 29
It was set to 0 ° C. Although the extruded mixture had a diameter of 3 mm, the mixture was water-cooled while being taken up to a diameter of 1 mm to form a strand. The take-up speed at this time is 0.
8 m / sec and the apparent extension rate given to the mixture was 3 × 10 / sec. 3 m of the obtained strand
It was cut into m length and pelletized.

Subsequently, 3 kg of the pellets having a length of 3 mm, 0.5 kg of silane-modified polypropylene (manufactured by Mitsubishi Chemical Corporation, trade name: Linklon HPM800HM), and a master batch of silane cross-linking catalyst (manufactured by Mitsubishi Chemical Corporation, trade name: PZ-10)
S) 0.025 kg and a pyrolytic foaming agent (manufactured by Otsuka Chemical Co., trade name: Uniform AZ SO-20) 0.3
5kg is blended and a twin screw extruder (Ikekai Kiko Co., Ltd.
After melt-kneading under the trade name PCM-30), width 300m
m, extruded from a sheet die having a lip clearance of 3 mm, and cooled and formed into a sheet by passing between a pair of water-cooled opposing rolls to obtain a foamable sheet for a substrate.
The obtained foamable base sheet has a thickness of 3 mm and a width of 250 mm.
Met.

The foamable sheet for base material is continuously heated at 100 ° C.
For 2 hours with hot water. The crosslinked foamable base sheet was heated in an oven controlled at 220 ° C. to cause foaming, and then air-cooled to obtain a flat foamed base material. In this foam base material, cells were three-dimensionally reinforced with a fibril-like liquid crystal polymer. The thickness of this foam base material is 8 m
m and the expansion ratio was 15 times. This foam base material and the foamable sheet for lamination made of the polypropylene and the liquid crystal polymer obtained in Example 1 were heated to 180 ° C. to be in a molten state, then both were laminated, and cooled while applying a pressing force. To obtain a liquid crystal polymer reinforced foam.
In addition, when laminating this foam base material and the foamable sheet for lamination, cooling was performed while applying a pressing force. The pressing force at this time was 1 kg / cm ² . The same evaluation as in Example 1 was performed on the obtained liquid crystal polymer reinforced foam, and the results are shown in Table 1.

[0101]

[Table 1]

[0102]

The liquid crystal polymer reinforced foam of the first invention is
The composite (I) having the above-described configuration, in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in a unidirectional orientation as a foamed sheet, on at least one surface of a thermoplastic resin foam base material. Thereby, it has excellent bending strength and extremely excellent dimensional stability in the orientation direction. Further, by laminating a composite (II) in which fibril-like liquid crystal polymers are three-dimensionally dispersed in a random manner in a thermoplastic resin as a foamed sheet, it has higher bending strength and dimensional stability.

The liquid crystal polymer reinforced foam of the second invention has the above-described structure, and the fibril-like liquid crystal polymer is dispersed and arranged in the thermoplastic resin foam base material, so that the fibril-form having a high elastic modulus is provided. The cell walls of the foam base material are reinforced by the liquid crystal polymer of the formula (1) to form a highly rigid foam.

The production method of the third invention has the above-mentioned structure, and obtains a liquid crystal polymer obtained by laminating and integrating a melt-kneaded product of a thermoplastic resin and a liquid crystal polymer with a thermoplastic foam base while stretching. Reinforced foams have excellent interfacial adhesion and dimensional stability.

The liquid crystal polymer reinforced foam of the fourth invention has the above-mentioned structure, and most of the liquid crystal polymer fibrils are placed in at least one surface of the thermoplastic foam base material in the thermoplastic resin as a thermoplastic resin sheet. The liquid crystal polymer fibrils are aligned in a different direction from this alignment direction, and the composite (III) is laminated and integrated.
Anisotropy is eliminated, and dimensional stability and mechanical properties are excellent.

The liquid crystal polymer reinforced foam of the fifth invention has the above-described structure, and the composite of the fourth invention (the thermoplastic resin foam base material in which liquid crystal polymer fibrils having a high elastic modulus are randomly dispersed and arranged) is provided. Since III) is laminated and integrated, anisotropy is further eliminated, and dimensional stability and mechanical properties are excellent.

[Brief description of the drawings]

FIG. 1 shows a liquid crystal polymer in which a composite (I) in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in one direction is laminated on a foamed sheet on both surfaces of a thermoplastic resin foam base material. It is a schematic diagram which shows a reinforced foam.

FIG. 2 is a composite in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in a unidirectional orientation on both surfaces of a foam base material in which liquid crystal polymers are randomly oriented in a three-dimensional direction. It is a schematic diagram which shows the liquid crystal polymer reinforced foam on which (I) was laminated.

[FIG. 3] A composite (II) in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in a three-dimensionally random state is laminated on both sides of a thermoplastic resin foam base material in a foamed sheet. FIG. 3 is a schematic view showing a liquid crystal polymer reinforced foam obtained.

FIG. 4 shows a state in which a fibril-like liquid crystal polymer is randomly oriented in a three-dimensional direction in a thermoplastic resin on both sides of a foam base material in which a liquid crystal polymer is randomly oriented in a three-dimensional direction. It is a schematic diagram which shows the liquid crystal polymer reinforced foam on which the composite (II) dispersed was laminated.

FIG. 5 is a schematic diagram showing a state in which most of the fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in a state of being oriented in one direction, and a part is dispersed in a state of being oriented in a direction different from the orientation direction. is there.

FIG. 6 is a schematic diagram showing a method of traversing a comb having a plurality of protrusions with an air cylinder or the like.

FIG. 7 shows a state where most of the liquid crystal polymer fibrils are oriented in one direction in the thermoplastic resin on both surfaces of the thermoplastic resin foam base material, and some liquid crystal polymer fibrils are oriented in a direction different from this orientation direction. FIG. 3 is a schematic view showing a liquid crystal polymer reinforced foam in which a composite (III) dispersed in the above is laminated.

FIG. 8: Most of liquid crystal polymer fibrils are oriented in one direction in a thermoplastic resin on both surfaces of a foam base material in which liquid crystal polymers are randomly oriented in a three-dimensional direction, and some of the liquid crystal polymer fibrils are oriented in this direction. FIG. 3 is a schematic diagram showing a liquid crystal polymer reinforced foam in which a composite (III) dispersed in a state of being oriented in a direction different from the direction is laminated.

Continued on the front page F-term (reference) 4F074 AA24 AA65 AA73 AA97 AA98 AE04 BA12 CA22 CE25 CE46 CE59 CE65 CE98 DA02 DA08 DA20 DA24 4F100 AK01A AK01B AK01C AK07 BA02 BA03 BA06 BA10B BA10C BA22 BA27 CA23A DJ00 GBB JA23 JB16A JB16B JB16C JJ02 JK04 JK07 JL04 YY00B YY00C

Claims (5)

[Claims] 1. A liquid crystal polymer reinforced foam in which a foam sheet having an expansion ratio of 5 times or less is laminated on at least one surface of a foam base material made of a thermoplastic resin, wherein the foam sheet is
Composite (I) in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in a unidirectionally oriented state, or a composite in which a fibril-like liquid crystal polymer is three-dimensionally dispersed in a thermoplastic resin in a random state A liquid crystal polymer reinforced foam comprising (II). 2. 70 to 99% by weight of a thermoplastic resin and 3
A liquid crystal polymer reinforced foam in which a foam sheet having an expansion ratio of 5 times or less is laminated on at least one surface of a foam base material comprising 0 to 1% by weight of a fibril liquid crystal polymer, wherein the foam sheet is a thermoplastic resin. A composite (I) in which a fibril-like liquid crystal polymer is dispersed in one direction in a composite (I) or a composite in which a fibril-like liquid crystal polymer is three-dimensionally dispersed in a thermoplastic resin in a random state (I)
A liquid crystal polymer reinforced foam characterized by comprising I). 3. A resin composition comprising a thermoplastic resin and a liquid crystal polymer is melted and kneaded in an extruder, and a physical foaming agent which exhibits a gaseous state at normal temperature and normal pressure is dissolved under high pressure. On at least one side of a foam base material obtained by discharging and foaming from the above, a foam sheet having a foaming ratio of 5 times or less in which a fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in a unidirectional orientation is laminated. A method for producing a liquid crystal polymer reinforced foam, characterized by being integrated. 4. A liquid crystal polymer reinforced foam in which a thermoplastic resin sheet made of a thermoplastic resin and a fibril-like liquid crystal polymer is laminated on at least one surface of a foam base material made of a thermoplastic resin. The thermoplastic resin sheet is a composite (II) in which most of the fibril-like liquid crystal polymer is dispersed in a thermoplastic resin in a state of being oriented in one direction, and a part of the liquid crystal polymer is dispersed in a state of being oriented in a different direction.
I) A liquid crystal polymer reinforced foam characterized by comprising: 5. A foam base material made of a thermoplastic resin, comprising 70 to 99% by weight of the thermoplastic resin and 30 to 1% by weight of a fibril-like liquid crystal polymer.
A liquid crystal polymer reinforced foam as described in the above.