JP2018165331A - Resin molded body and method for producing the same - Google Patents

Abstract

Disclosed is a resin molded body that has ultrahigh molecular weight polyethylene as a main component, has excellent slidability and mechanical strength, and can be continuously manufactured by extrusion molding regardless of the molecular weight of ultrahigh molecular weight polyethylene, and a method for producing the same. . A resin molding comprising a resin composition containing ultrahigh molecular weight polyethylene (A) and a liquid lubricant (B), wherein the total amount of the resin composition is 100% by mass (B ) The content of the component is 0.1 to 10% by mass, the kinematic viscosity of the component (B) at a temperature of 25 ° C. is 200 mm 2 / s to 50,000 mm 2 / s, and the resin composition contains a fluororesin And a resin molded body in which the amount of agglomerates having a diameter of 1 mm or more present in the resin molded body is less than 0.01% by volume, and a production method thereof. [Selection figure] None

Description

  The present invention relates to a resin molded body and a method for producing the same.

  Ultra high molecular weight polyethylene is known as a material having high mechanical strength, impact resistance, wear resistance, and slidability among thermoplastic resins, and also has food safety. Therefore, a molded article of a resin composition containing ultrahigh molecular weight polyethylene is useful as a sliding member used for a guide rail, a slider for transportation, or the like in a manufacturing apparatus in the food or pharmaceutical field. In recent years, the performance required for further slidability and longer life has become stricter, and it has been required to provide a high level of slidability that cannot be expressed by ultra-high molecular weight polyethylene alone.

  Methods for improving the slidability of ultra-high molecular weight polyethylene include blending a fluororesin and a lubricating aid such as silicone oil and paraffin oil (Patent Document 1), and blending oil-containing porous silica. (Patent Document 2) and the like are known. By using a resin composition in which these components are blended with ultrahigh molecular weight polyethylene for various molding methods, a resin molded article having excellent slidability can be produced.

JP 2008-156561 A JP 2008-174593 A

The resin composition (dry blend product) mainly composed of ultrahigh molecular weight polyethylene is usually a powder mixture. Examples of the molding method of the powder mixture include compression molding and extrusion molding. For example, in order to continuously produce a long molded body such as a rail in a production line of several meters, an extrusion molding method is used. It is preferable to use it.
The ultrahigh molecular weight polyethylene used in Examples of Patent Documents 1 and 2 has a molecular weight of about 300,000 to 2.9 million, and has a relatively low molecular weight among ultrahigh molecular weight polyethylenes. Therefore, the resin compositions described in Examples of Patent Documents 1 and 2 can be melt-extruded. However, ultrahigh molecular weight polyethylene has a problem that the higher the molecular weight, the more difficult it is to melt and the difficulty of melt extrusion.

Therefore, when extruding a powder mixture containing ultra-high molecular weight polyethylene having a higher molecular weight, it is preferable to directly supply the powder mixture to an extruding machine for molding.
However, as in the sliding material composition disclosed in Patent Document 2, if the amount of the liquid component such as a liquid lubricant is large relative to the powder mixture, agglomerates are likely to occur, and the fluidity of the powder. Also decreases. As a result, when the powder mixture is directly supplied to the extrusion molding machine, there is a problem that clogging occurs in the molding machine and it becomes difficult to continuously produce a resin molded body. Further, the obtained resin molded body is easily broken when stress is applied, and has a low mechanical strength. On the other hand, if the blending amount of the liquid lubricant is reduced, the slidability of the obtained resin molded product is lowered.

  An object of the present invention is to provide a resin molded article that has ultra-high molecular weight polyethylene as a main component, is excellent in slidability and mechanical strength, and can be continuously manufactured by extrusion molding regardless of the molecular weight of ultra-high molecular weight polyethylene. is there.

As a result of intensive studies, the present inventors have found that the above problems can be solved by setting the resin composition constituting the resin molded body to a predetermined composition, and have completed the present invention.
That is, the present invention relates to the following [1] to [8].
[1] A resin molding comprising a resin composition containing ultrahigh molecular weight polyethylene (A) and a liquid lubricant (B), wherein the total amount of the resin composition is 100% by mass (B) a content of the component from 0.1 to 10 wt%, a kinematic viscosity at 25 ° C. of the component (B) is 200mm ² / s~5 ten thousand ^mm 2 / s, the resin composition a fluororesin A resin molded body which is not contained and the amount of aggregates having a diameter of 1 mm or more present in the resin molded body is less than 0.01% by volume.
[2] The resin molded article according to the above [1], wherein the resin composition further contains an inorganic filler (C).
[3] The resin molded article according to the above [2], wherein the component (C) is at least one selected from the group consisting of talc, mesoporous silica, and zeolite.
[4] The resin molded body according to any one of [1] to [3], wherein the resin composition further contains high-density polyethylene as a resin component (D) other than the component (A).
[5] The content described in any one of [1] to [4] above, wherein the content of the component (A) is 60 to 99.9% by mass when the total amount of the resin composition is 100% by mass. Resin molded body.
[6] The resin molded body according to any one of [1] to [5], wherein the resin molded body is a molded body obtained by compression molding or extrusion molding the resin composition.
[7] The resin molded product according to [6], wherein the resin molded product is a molded product obtained by ram extrusion molding the resin composition.
[8] The resin composition according to any one of [1] to [7], wherein the resin composition is a powder mixture containing the component (A) and the component (B). A method for producing a resin molded body comprising the steps of preparing and then compressing or extruding the resin composition.

  ADVANTAGE OF THE INVENTION According to this invention, the resin molded object which has ultra high molecular weight polyethylene as a main component, is excellent in slidability and mechanical strength, and can also be continuously manufactured by extrusion molding can be provided. The said resin molding is suitable as sliding members, such as a rail and a slider.

[Resin molding]
The resin molded body of the present invention comprises a resin composition containing a high molecular weight polyethylene (A) and a liquid lubricant (B), and contains the component (B) when the total amount of the resin composition is 100% by mass. the amount is 0.1 to 10 mass%, kinematic viscosity at 25 ° C. of the component (B) is 200mm ² / s~5 ten thousand ^mm 2 / s, the resin composition contains no fluororesin And the quantity of the aggregate of diameter 1mm or more which exists in this resin molding is less than 0.01 volume%, It is characterized by the above-mentioned. Since the resin molded body of the present invention has the above-described configuration, both high slidability and mechanical strength can be achieved, and continuous production by extrusion molding is also possible. The resin composition may further contain a resin component (D) other than the component (A) such as an inorganic filler (C) described later and high-density polyethylene.

The resin molded body of the present invention is an amount of an aggregate having a diameter of 1 mm or more (hereinafter, also simply referred to as “aggregate”) present in the resin molded body from the viewpoint of developing good slidability and mechanical strength. Is less than 0.01% by volume. Mechanical strength falls that the quantity of the said aggregate in a resin molding is 0.01 volume% or more. The amount of the aggregate is obtained by visually observing the surface of the resin molded body, obtaining an area occupied by aggregates having a diameter of 1 mm or more existing in a 10 cm × 10 cm square, assuming that the aggregate is a sphere, and resin molding from here The amount (% by volume) of the aggregate per unit volume present in the body can be calculated. Specifically, it can be measured by the method described in the examples.
As a method of adjusting the amount of aggregates having a diameter of 1 mm or more in the resin molded body to the above range, selection of components and content constituting the resin composition used in the resin molded body, and components of the resin composition Examples include selection of a blending method and selection of a molding method of the resin composition.

  Examples of the resin molded body of the present invention include a molded body obtained by compression molding or extrusion molding the resin composition. For example, when the resin molded body of the present invention is a long resin molded body such as a rail, the resin molded body is preferably a molded body obtained by extruding the resin composition, and the resin composition is ram extruded. More preferably, it is a molded body.

The resin composition used for molding the resin molded product of the present invention is preferably a powder mixture. The resin composition is less likely to generate agglomerates, and even when directly subjected to extrusion molding in the form of a powder mixture, there is no problem such as clogging in the molding machine, and continuous production of molded articles by extrusion molding is easy. . In addition, the obtained resin molded body has high slidability that cannot be expressed by ultra high molecular weight polyethylene alone, and has good mechanical strength.
Hereinafter, each component in the resin composition which comprises the resin molding of this invention is demonstrated.

<Ultra high molecular weight polyethylene (A)>
The resin composition constituting the resin molded body of the present invention contains ultra high molecular weight polyethylene (A) (hereinafter also simply referred to as “component (A)”) as a main component. In the present invention, the “main component” means that the content when the total amount of the resin composition is 100% by mass is preferably 50% by mass or more, more preferably 55% by mass or more, and further preferably 60% by mass or more. It means that there is.
The viscosity average molecular weight [g / mol] of the ultrahigh molecular weight polyethylene (A) in the present invention is preferably 1 million or more, more preferably 2 million or more, from the viewpoint of mechanical strength and slidability of the obtained resin molded product. More preferably, it is 3 million or more, and still more preferably 4 million or more.
In the present invention, the viscosity average molecular weight is a value determined by the Margoli's formula shown below.
M = 5.37 · 10 ⁴ [η] ^1.49
In the above formula, M represents a viscosity average molecular weight [g / mol], and [η] represents an intrinsic viscosity (unit: [dl / g]).
Moreover, the density of (A) component is the range of 920-960 kg / m < ³ > normally, Preferably it is 920-950 kg / m < ³ >, More preferably, it is 925-945 kg / m < ³ >, More preferably, it is 925-940 kg / m < ³ >. Range.

  Examples of commercially available ultra-high molecular weight polyethylene include “GUR” manufactured by Ticona, “Sunfine” (registered trademark) manufactured by Asahi Kasei Co., Ltd., “Hi-Zex Million” manufactured by Mitsui Chemicals, Tosoh "Decamylene" manufactured by Co., Ltd. can be used. These may be used alone or in combination of two or more at any ratio.

  The content of the component (A) in the resin composition is preferably 60 to 99.9% by mass, more preferably as the content of the component (A) when the total amount of the resin composition is 100% by mass. Is 65 to 99.5% by mass, more preferably 70 to 99% by mass, still more preferably 75 to 99% by mass, still more preferably 80 to 99% by mass, and still more preferably 85 to 99% by mass. If the content of the component (A) when the total amount in the resin composition is 100% by mass is 60% by mass or more, the resulting resin molded product has mechanical strength and impact resistance derived from the component (A). , Wear resistance, and slidability. On the other hand, if the said content is 99.9 mass% or less, the slidability improvement effect by (B) component is favorable.

<Liquid lubricant (B)>
The resin composition constituting the resin molded body of the present invention is a liquid lubricant (B) (hereinafter, simply referred to as “lubricant (B)” or “from the viewpoint of imparting high slidability that cannot be expressed by ultrahigh molecular weight polyethylene alone”. (Also referred to as “component (B)”). The liquid lubricant in the present invention means a liquid lubricant under the condition of 25 ° C. The kinematic viscosity at 25 ° C. of the liquid lubricant (B) is 200 mm ² / s or more, preferably 300 mm ² / s or more, more preferably 500 mm ² / s or more from the viewpoint of imparting slidability. Moreover, kinematic viscosity at 25 ° C. a liquid lubricant (B) from the viewpoint of aggregates reduced, or less 50,000 ^mm 2 / s, preferably 40,000 ^mm 2 / s or less, more preferably 30,000 ^mm 2 / s or less.
When a liquid lubricant having a kinematic viscosity at 25 ° C. of less than 200 mm ² / s is used, a sufficient slidability improving effect cannot be obtained. When a liquid lubricant having a kinematic viscosity at 25 ° C. exceeding 50,000 mm ² / s is used, aggregates are likely to be generated in the resin composition and the obtained resin molded body.
The kinematic viscosity at 25 ° C. of the liquid lubricant can be measured according to ASTM D 445-46T.

(B) As a lubricant which is a component, 1 or more types chosen from the group which consists of mineral oil, synthetic oil, and natural oil are mentioned. Examples of the mineral oil include paraffinic oil and naphthenic oil, and examples of the synthetic oil include synthetic hydrocarbon, synthetic ester, polyglycol, phosphate ester, and silicone oil. Natural oils include palm oil, palm oil, rapeseed oil, corn oil, olive oil, soybean oil, sunflower oil, castor oil, linseed oil and the like. The said lubricant can be used individually by 1 type or in combination of 2 or more types.
Among these, from the viewpoint of imparting slidability and heat resistance, the component (B) is preferably a synthetic oil, and more preferably a silicone oil. Examples of the silicone oil include a silicone oil having a polysiloxane structure, and a silicone oil having a polydimethylsiloxane structure is preferable from the viewpoint of imparting slidability, fluidity, and heat resistance.

  Content of (B) component in the said resin composition is 0.1-10 mass% as content of (B) component when the total amount of this resin composition is 100 mass%, Preferably it is 0. It is 5-9 mass%, More preferably, it is 0.5-7 mass%, More preferably, it is 0.5-5 mass%. When the content of the component (B) is less than 0.1% by mass when the total amount of the resin composition is 100% by mass, the slidability of the obtained resin molded product is insufficient. On the other hand, when the content of the component (B) exceeds 10% by mass, there is a risk of an increase in aggregates and a decrease in mechanical strength.

  The resin composition constituting the resin molded body of the present invention does not contain a fluororesin from the viewpoint of reducing the generation of aggregates. The fluororesin here is a resin component containing a fluorine atom, and is a solid fluororesin at room temperature (25 ° C.). When the fluororesin is blended with a powder mixture containing the component (A) and the component (B), the powder fluidity is lowered and agglomerates are easily generated, which is unsuitable for use in extrusion molding.

<Inorganic filler (C)>
The resin composition constituting the resin molded body of the present invention contains the liquid lubricant (B) from the viewpoint of imparting high slidability that cannot be expressed with a single ultrahigh molecular weight polyethylene, but reduces the amount of aggregates. Therefore, it is preferable to further contain an inorganic filler (C) (hereinafter also simply referred to as “component (C)”). When the resin composition contains the inorganic filler (C), the liquid lubricant (B) is supported on the inorganic filler (C), whereby a powder mixture containing the component (A) and the component (B). Generation | occurrence | production of the aggregate in a certain resin composition and the resin molding obtained can be reduced.
The average particle diameter of the inorganic filler (C) is preferably 0.1 to 100 μm, more preferably 0.1 to 50 μm, still more preferably 0.5 to 30 μm, still more preferably 0.5 to 10 μm, and still more preferably. 0.5-5 μm. If the average particle size of the inorganic filler (C) is 0.1 μm or more, the supporting effect of the component (B) can be easily exerted, and if it is 100 μm or less, the mechanical strength does not decrease.

  Examples of the inorganic filler that is component (C) include talc, calcium oxide, magnesium oxide, silica, zeolite, calcium carbonate, zonotrite, mica, and clay. The said inorganic filler can be used individually by 1 type or in combination of 2 or more types.

  Silica is preferably silica gel or mesoporous silica, and more preferably mesoporous silica. From the viewpoint of the effect of supporting the component (B), the pore diameter of the mesoporous silica is preferably 0.5 nm or more, more preferably 1 nm or more, and further preferably 2 nm or more. The pore diameter of mesoporous silica is preferably 30 nm or less, more preferably 20 nm or less, and still more preferably 15 nm or less from the viewpoint of imparting slidability.

  The pore diameter of the zeolite is preferably 0.1 to 5 nm, more preferably 0.2 to 3 nm, from the viewpoint of the effect of supporting the component (B) and imparting slidability.

  Among these, from the viewpoint of the effect of reducing aggregates by supporting the component (B), the inorganic filler (C) is more preferably at least one selected from the group consisting of talc, mesoporous silica, and zeolite, and talc and mesoporous silica. One or more selected from the group consisting of

  The content of the component (C) in the resin composition is preferably 0.1 to 5% by mass as the content of the component (C) when the total amount of the resin composition is 100% by mass, More preferably, it is 0.1-3 mass%, More preferably, it is 0.2-2 mass%, More preferably, it is 0.2-1 mass%. If the content of the component (C) is 0.1% by mass or more when the total amount of the resin composition is 100% by mass, the effect of reducing aggregates is good. On the other hand, if content of (C) component is 5 mass% or less, there is no possibility that mechanical strength will fall.

<Resin component (D) other than (A) component>
The resin composition constituting the resin molded body of the present invention may further contain a resin component (D) other than the component (A) (hereinafter also simply referred to as “component (D)”). Examples of the component (D) include high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and medium density polyethylene (MDPE). The said resin component can be used individually by 1 type or in combination of 2 or more types. Of these, HDPE is preferred as the component (D) from the viewpoint of heat resistance and mechanical strength. The melt flow rate (MFR) of HDPE is preferably from 0.1 to 10 g / min, more preferably from 0.1 to 5 g / min, and even more preferably from the viewpoint of improving the elongation of the obtained resin molding. 1 to 2 g / min. HDPE MFR is measured according to JIS K7210.
Although there is no restriction | limiting in particular if content of (D) component in the said resin composition is a range which does not impair the effect of this invention, When (D) component when the total amount of a resin composition is 100 mass% As content, Preferably it is 1-30 mass%, More preferably, it is 2-25 mass%, More preferably, it is 5-20 mass%. By containing 1% by mass or more of the component (D), an improvement in the elongation of the obtained resin molded product can be expected, and if it is 30% by mass or less, the slidability is hardly lowered.

<Heat stabilizer>
The resin composition constituting the resin molded body of the present invention can further contain a thermal stabilizer in order to suppress thermal deterioration during molding. From the viewpoint of obtaining a powder mixture with few aggregates, a heat stabilizer is preferably used.
Examples of heat stabilizers include hindered phenol heat stabilizers, phosphorus heat stabilizers, amine heat stabilizers, sulfur heat stabilizers, amide heat stabilizers, and hydrazine heat stabilizers. One type can be used alone, or two or more types can be used. Among these, at least one selected from the group consisting of a hindered phenol heat stabilizer and a phosphorus heat stabilizer is preferable from the viewpoint of suppressing thermal deterioration during molding.

As the hindered phenol-based heat stabilizer, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (“IRGANOX 1010” manufactured by BASF Japan Ltd.), thiodiethylene Bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (“Irganox 1035” manufactured by BASF Japan Ltd.), octadecyl [3- (3,5-di-tert-butyl -4-hydroxyphenyl) propionate] (BASF Japan Ltd., Irganox 1076), octyl 3- (4-hydroxy-3,5-diisopropylphenyl) propionate ("Irganox 1135" manufactured by BASF Japan Ltd.) , N-octadecyl-3- (3′-methyl-5 '-Tert-butyl-4'-hydroxyphenyl) propionate, n-tetradecyl-3- (3', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate, 1,6-hexanediol-bis- (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), 1,4-butanediol-bis- (3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate), triethylene glycol-bis- [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] and the like. These can be used alone or in combination of two or more.
Among the above, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate], octadecyl [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], and octyl 3- (4-hydroxy-3,5-diisopropylphenyl) propionate One or more of these are preferable, and pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] is more preferable.

The phosphorus heat stabilizer is preferably a phosphite phosphorus heat stabilizer, such as triphenyl phosphite, trisnonylphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite (BASF). Japan Co., Ltd., Irgaphos 168), trioctyl phosphite, tridecyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, butyl diphenyl phosphite, decyl diphenyl Phosphite, octyl diphenyl phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4,6-di-tert-butyl phosphite) Nyl) octyl phosphite, bis (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,4-dicumylphenyl) pentaerythritol diphos Phyto, distearyl pentaerythritol diphosphite, etc. are mentioned. These can be used alone or in combination of two or more.
Among the above, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4 , 6-di-tert-butylphenyl) octyl phosphite, bis (nonylphenyl) pentaerythritol diphosphite, and bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite One or more are preferable, and tris (2,4-di-tert-butylphenyl) phosphite is more preferable.

From the viewpoint of suppressing thermal deterioration during molding, it is more preferable to use a hindered phenol-based heat stabilizer and a phosphorus-based heat stabilizer in combination as the heat stabilizer. A particularly preferred combination is a combination of pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and tris (2,4-di-tert-butylphenyl) phosphite. .
When the hindered phenol heat stabilizer and the phosphorus heat stabilizer are used in combination, the mixing ratio is not particularly limited, but the mass ratio of the hindered phenol heat stabilizer to the phosphorus heat stabilizer is preferably 5 / 95 to 95/5, more preferably 20/80 to 80/20, and still more preferably 30/70 to 70/30.

  The content of the heat stabilizer in the resin composition is preferably 0.01 to 2% by mass, more preferably 0.02 to 1% by mass as the content when the total amount of the resin composition is 100% by mass. More preferably, it is 0.02-0.5 mass%. If the content is 0.01% by mass or more, an effect of suppressing thermal deterioration is exhibited, and if it is 2% by mass or less, mechanical strength and slidability can be maintained.

  If necessary, the resin composition may further contain a solid lubricant such as silicone resin powder or wax as long as the effects of the present invention are not impaired. However, since the resin composition contains a predetermined amount of the component (B), it is not necessary to further blend a solid lubricant, and it is more preferable not to blend a solid lubricant.

  If necessary, the resin composition may further contain additives other than those described above as long as the effects of the present invention are not impaired. Specifically, for example, organic or inorganic colorants as colorants; light stabilizers (UV absorbers); inorganic, halogen or phosphorus flame retardants as flame retardants; nucleating agents as impact modifiers, impact resistance Plasticizers, dispersants, fluidity improvers, mold release agents, and the like are examples of moldability and processability improvers. These may be used alone or in combination of two or more at any ratio.

<Physical properties of resin molding>
The resin molded body of the present invention preferably has a dynamic friction coefficient of 0.200 or less, more preferably 0.190 or less, still more preferably 0, as measured by a method according to JIS K7125: 1999. 150 or less, more preferably 0.120 or less. When the coefficient of dynamic friction is 0.200 or less, the slidability is good, and wear deterioration when the resin molded body of the present invention is used for a guide rail of a manufacturing apparatus, a slider for conveyance, or the like is suppressed. be able to.

  The resin molded body of the present invention preferably has a test piece shape: ASTM D638 type IV test piece, a tensile rate of 50 mm / min, and a tensile breaking strength measured at a temperature of 23 ° C. is 15 MPa or more, more preferably 18 MPa or more. Yes, more preferably 20 MPa or more. If the tensile strength at break is 15 MPa or more, damage due to insufficient strength hardly occurs. Similarly, the tensile elongation at break measured is preferably 30% or more, more preferably 50% or more, and still more preferably 60% or more. If the tensile elongation at break is 50% or more, the resin molded body of the present invention is less likely to be damaged in the step of fitting into an apparatus when used for a guide rail of a manufacturing apparatus or a transfer slider.

[Method for producing resin molded body]
The manufacturing method of the resin molding of this invention is not specifically limited, According to a desired shape, it can select suitably. For example, the resin composition which is a powder mixture containing the component (A) and the component (B) is prepared by mixing the component (A) and the component (B) and other components as necessary. The method which has the process of compression-molding or extrusion-molding this resin composition is mentioned. Hereinafter, this production method is also referred to as “the production method of the present invention”. From the viewpoint of producing a long resin molded article by continuous molding, the method for producing a resin molded article of the present invention preferably has a step of extruding the resin composition, more preferably by ram extrusion molding. preferable.

The resin composition used in the production method of the present invention can be prepared by any method. For example, the component (A) and the component (B), and other components used as necessary may be a tumbler mixer or a Henschel mixer. The method of using and dry blending is mentioned. For example, it is also possible to dry blend a powder raw material in which the component (B) and the component (D) are master batched.
A conventionally known method can be used for the compression molding. For example, a resin composition that is a powder mixture is charged into a mold, and compression molding is performed using a compression molding machine under conditions of a molding temperature of 160 to 240 ° C. and a molding pressure of 2 to 50 MPa.

Conventionally known methods can also be used for extrusion molding. However, it is preferable to use ram extrusion molding from the viewpoint of directly subjecting the resin composition, which is a powder mixture, to direct extrusion molding without being pelletized.
For example, ram extrusion is performed as follows. First, a resin composition that is a powder mixture is charged into a cylinder from a hopper of a ram extruder. The resin composition is heated in a cylinder and pressed and compressed by a ram. The compressed resin composition moves in the cylinder while being gradually melted, and the components in the resin composition are sintered and joined, and finally extruded from the tip of the cylinder to be molded. In the production method of the present invention, the molding temperature at the time of extrusion molding may be 160 to 240 ° C., for example, and the extrusion speed may be 1 to 500 mm / min.

According to the production method of the present invention, it is possible to continuously produce a long resin molded body such as a rail by including the step of extrusion molding the resin composition preferably as described above.
The obtained resin molding can be expected to be applied to various sliding members. Examples of the sliding member include a guide rail of a manufacturing apparatus, a transport slider, a star wheel, a transport screw, a neck guide, a conveyor roller, a raw material charging chute, and the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples without departing from the gist thereof. Various measurements and evaluations in the examples were performed by the following methods.

(1) Amount of Aggregate in Resin Molded Body Using the resin composition obtained in each example, a flat resin molded body having a thickness of 2 mm was produced by the molding method described in each example. By visually observing the surface of the resin molded body, the area occupied by aggregates having a diameter of 1 mm or more existing within a 10 cm × 10 cm square is obtained, and the aggregate is assumed to be a sphere and is present in the resin molded body from here. The amount (volume%) of the aggregate per unit volume was calculated. The evaluation criteria are as follows.
○: Less than 0.01% by volume, ×: 0.01% by volume or more

(2) Coefficient of dynamic friction Using the resin composition obtained in each example, a plate-shaped resin molded body or extruded rail having a thickness of 5 mm was prepared by the molding method described in each example, and used for measurement of the coefficient of dynamic friction. . The dynamic friction coefficient was measured by a method based on JIS K7125: 1999, and an average value measured four times was used as a measured value. The evaluation criteria are as follows.
<Evaluation criteria>
○: 0.200 or less, ×: more than 0.200

(3) Tensile rupture strength, tensile rupture elongation Using the resin composition obtained in each example, a molded article of test piece shape: ASTM D638 type IV was prepared by a molding method described in each example, and a tensile speed of 50 mm / The tensile strength at break and the tensile elongation at break were measured at a temperature of 23 ° C. In addition, the average value measured 5 times was made into the measured value. The evaluation criteria are as follows.
<Evaluation criteria>
(Tensile strength at break)
○: 15 MPa or more, x: less than 15 MPa (tensile elongation at break)
○: 30% or more, ×: less than 30%

Each component used in each example is shown below.
<Ultra high molecular weight polyethylene>
(A1): Ultra high molecular weight polyethylene, “Sunfine UH950” manufactured by Asahi Kasei Corporation, viscosity average molecular weight: 4.5 million [g / mol], density: 933 kg / m ³
(A2): Ultra high molecular weight polyethylene, “GUR4150” manufactured by Ticona, viscosity average molecular weight: 9.2 million [g / mol], density: 928 kg / m ³

<Liquid lubricant>
(B1): Silicone oil having a polydimethylsiloxane structure, “KF96-1000cs” manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25 ° C.): 1,000 mm ² / s
(B2): Silicone oil having a polydimethylsiloxane structure, “KF96-5000cs” manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25 ° C.): 5,000 mm ² / s
(B3): Silicone oil, silicone oil in masterbatch powder (E1) (high density polyethylene / silicone oil = 85/15 (mass ratio)), kinematic viscosity (25 ° C.): 30,000 mm ² / s
(B1): Silicone oil having a polydimethylsiloxane structure, “KF96-100cs” manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25 ° C.): 100 mm ² / s

<Inorganic filler>
(C1): Mesoporous silica, “MP09005” manufactured by Nippon Kasei Co., Ltd., average particle size: 5 μm, pore size: 9 nm
(C2): Mesoporous silica, “MP02005” manufactured by Nippon Kasei Co., Ltd., average particle size: 5 μm, pore size: 2 nm
(C3): Talc, “Nanoace D-1000” manufactured by Nippon Talc Co., Ltd., average particle size (D50): 1 μm

<Resin other than ultra high molecular weight polyethylene (A)>
(D1): High density polyethylene, “Sunfine SH800” manufactured by Asahi Kasei Corporation, viscosity average molecular weight: 250,000 [g / mol], MFR (JIS K7210): 0.2 g / 10 min (D2): High density polyethylene , High density polyethylene in masterbatch powder (E1) (high density polyethylene / silicone oil = 85/15 (mass ratio)), MFR (JIS K7210, load 5 kg): 0.21 g / 10 min

<Heat stabilizer>
“Irganox B215” manufactured by BASF Japan Ltd., 33% by mass of pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and tris (2,4-di-tert) -Butylphenyl) phosphite with 67% by weight

<Fluorine resin>
“Fluoroslip 425” manufactured by Shamrock Technologies, polytetrafluoroethylene / polyethylene alloy powder

Example 1 Production of Resin Composition and Resin Molded Body 980 g of ultrahigh molecular weight polyethylene (A1) and 20 g of silicone oil (B1) were mixed with a Henschel mixer to obtain a resin composition that was a powder mixture. Next, the resin composition was put into a molding die having a predetermined test piece shape used for each evaluation, and compression molded at a temperature of 180 ° C. and a pressure of 10 MPa to produce a resin molded body.
About the obtained resin molding, it evaluated by the said method. The results are shown in Table 1.

(Example 2)
Implemented except that the composition of the resin composition was 977 g of ultrahigh molecular weight polyethylene (A2), 20 g of silicone oil (B1), and mesoporous silica (C1) (manufactured by Nippon Kasei Co., Ltd .: pore diameter 9 nm, average particle diameter 5 μm). A resin composition and a resin molded body were prepared by the same method as in Example 1, and evaluated by the above method. The results are shown in Table 1.

(Example 3)
A resin composition and a resin molded body were prepared in the same manner as in Example 1 except that the composition of the resin composition was 987 g of ultrahigh molecular weight polyethylene (A2), 10 g of silicone oil (B1), and 3 g of mesoporous silica (C1). The evaluation was performed by the above method. The results are shown in Table 1.

Example 4
A resin composition and a resin molded body were prepared in the same manner as in Example 1 except that the composition of the resin composition was 974 g of ultrahigh molecular weight polyethylene (A1), 20 g of silicone oil (B1), and 6 g of mesoporous silica (C1). The evaluation was performed by the above method. The results are shown in Table 1.

(Example 5)
The resin composition obtained in Example 4 was extruded using a ram extruder at a cylinder temperature of 180 ° C. and an extrusion speed of 50 mm / min to produce a resin molded body. Table 1 shows the results of evaluating the obtained resin composition and resin molded body by the above method.

(Example 6)
Resin composition in the same manner as in Example 5 except that the composition of the resin composition was 774 g of ultra high molecular weight polyethylene (A1), 20 g of silicone oil (B1), 6 g of mesoporous silica (C1), and 200 g of high density polyethylene (D1). Articles and resin moldings were prepared and evaluated by the above methods. The results are shown in Table 1.

(Example 7)
A resin composition and a resin molded body were produced in the same manner as in Example 1 except that the composition of the resin composition was 974 g of ultrahigh molecular weight polyethylene (A2), 20 g of silicone oil (B2), and 6 g of mesoporous silica (C2). Then, the evaluation was performed by the above method. The results are shown in Table 1.

(Example 8)
The composition of the resin composition was 794 g of ultra high molecular weight polyethylene (A2), master batch powder (E1) of high density polyethylene and silicone oil (kinematic viscosity (25 ° C.): 30,000 mm ² / s) (high density polyethylene / A resin composition and a resin molded body were prepared in the same manner as in Example 1 except that 200 g of silicone oil = 85/15 (mass ratio) and 6 g of talc (C3) were used, and evaluation was performed by the above method. The results are shown in Table 1.

Example 9
Resin composition and resin were the same as in Example 1 except that the composition of the resin composition was 973 g of ultrahigh molecular weight polyethylene (A2), 20 g of silicone oil (B2), 6 g of mesoporous silica (C1), and 1 g of heat stabilizer. Molded bodies were prepared and evaluated by the method described above. The results are shown in Table 1.

(Example 10)
Resin composition and resin molding were carried out in the same manner as in Example 1 except that the composition of the resin composition was 973 g of ultrahigh molecular weight polyethylene (A1), 20 g of silicone oil (B2), 6 g of talc (C3), and 1 g of heat stabilizer. A body was prepared and evaluated by the method described above. The results are shown in Table 1.

(Comparative Example 1)
A resin composition and a resin molded body were prepared in the same manner as in Example 1 except that the amount of the resin composition was changed to 1000 g of ultrahigh molecular weight polyethylene (A1), and evaluated by the above method. The results are shown in Table 1.

(Comparative Example 2)
A resin composition and a resin molded body were prepared in the same manner as in Example 1 except that the composition of the resin composition was 980 g of ultrahigh molecular weight polyethylene (A2) and 20 g of silicone oil (b1), and evaluation was performed by the above method. It was. The results are shown in Table 1.

(Comparative Example 3)
Except that the composition of the resin composition was 943 g of ultrahigh molecular weight polyethylene (A1), 20 g of silicone oil (B2), 6 g of talc (C3), 1 g of heat stabilizer, and 30 g of fluororesin (extrusion) An attempt was made to produce a resin molded body by a molding method). However, since the fluidity of the resin composition (powder mixture) is poor, the raw material cannot be supplied to the extrusion molding machine, and a molded body cannot be produced.

(Comparative Example 4)
A resin composition and a resin molded body were prepared in the same manner as in Example 1, except that the resin composition was changed to 794 g of ultrahigh molecular weight polyethylene (A1), 200 g of silicone oil (B2), and 6 g of mesoporous silica (C2). The evaluation was performed by the above method. The results are shown in Table 1.

From Table 1, the resin composition which is the powdery mixture obtained in Examples 1 to 10 is excellent in moldability even if any one of the compression molding method and the extrusion molding method is used, and an aggregate having a diameter of 1 mm or more. Therefore, it was suitable for continuous production by extrusion molding. In addition, the obtained resin molding had a dynamic friction coefficient of 0.200 or less, excellent slidability, and good mechanical strength.
On the other hand, the resin molded body of Comparative Example 1 containing no component (B) and Comparative Example 2 using a liquid lubricant having a kinematic viscosity at 25 ° C. of less than 200 mm ² / s has a dynamic friction coefficient of 0. It exceeded 200 and the slidability was insufficient. Since the resin composition of Comparative Example 3 had many aggregates having a diameter of 1 mm or more and low powder flowability, extrusion molding could not be performed. Further, in Comparative Example 4 in which the content of the component (B) in the resin composition exceeds 10% by mass, there are many aggregates having a diameter of 1 mm or more, and the mechanical strength of the obtained resin molded body was lowered.

  ADVANTAGE OF THE INVENTION According to this invention, the resin molded object which has ultra high molecular weight polyethylene as a main component, is excellent in slidability and mechanical strength, and can also be continuously manufactured by extrusion molding can be provided. The said resin molding is suitable as sliding members, such as a rail and a slider.

Claims (8)

A resin molded body comprising a resin composition containing ultrahigh molecular weight polyethylene (A) and a liquid lubricant (B), the content of the component (B) when the total amount of the resin composition is 100% by mass the amount is 0.1 to 10 mass%, kinematic viscosity at 25 ° C. of the component (B) is 200mm ² / s~5 ten thousand ^mm 2 / s, the resin composition contains no fluororesin And the resin molding in which the quantity of the aggregate of diameter 1mm or more which exists in this resin molding is less than 0.01 volume%.   The resin molded product according to claim 1, wherein the resin composition further contains an inorganic filler (C).   The resin molded body according to claim 2, wherein the component (C) is one or more selected from the group consisting of talc, mesoporous silica, and zeolite.   The resin molded product according to any one of claims 1 to 3, wherein the resin composition further contains high-density polyethylene as a resin component (D) other than the component (A).   The resin molded product according to any one of claims 1 to 4, wherein the content of the component (A) when the total amount of the resin composition is 100% by mass is 60 to 99.9% by mass.   The resin molded body according to any one of claims 1 to 5, wherein the resin molded body is a molded body obtained by compression molding or extrusion molding the resin composition.   The resin molded body according to claim 6, wherein the resin molded body is a molded body obtained by ram extrusion molding the resin composition.   It is the manufacturing method of the resin molding of any one of Claims 1-7, Comprising: The resin composition which is a powder mixture containing the said (A) component and the said (B) component is prepared, Then, The manufacturing method of the resin molding which has the process of compression-molding or extrusion-molding this resin composition.