JP7119446B2 - Resin processing machine cleaning composition and resin processing machine cleaning method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composition for cleaning a resin processing machine and a method for cleaning a resin processing machine, and more particularly to a cleaning composition and a cleaning method effective for cleaning a resin processing machine processed with a silane-crosslinked polyolefin resin. is.

Molding machines and extruders (these are called "resin processing machines") commonly used in plastic molding process have a small amount of processed resin and The contained additives and the like remain inside the resin processing machine, specifically on the screw and inner wall of the cylinder of the molding machine or extruder. If a new resin is processed with the same resin processing machine while the residual resin and residual additives remain, the physical properties and characteristics of the resin itself obtained after molding may be affected. Therefore, in general, the inside of the resin processing machine to be used is cleaned in advance after molding the resin or before molding the new resin. The washing of the resin processing machine is usually carried out by using a cleaning resin composition, introducing the cleaning resin composition into the resin processing machine, and extruding, molding, kneading, etc., in the same manner as in the molding of ordinary products. By performing the above operation, the residual resin and additives inside the resin processing machine are entrained in the cleaning resin composition and removed by extrusion, or the residue is decomposed and removed using the cleaning resin composition. will be

The resin component of the cleaning resin composition used for cleaning the resin processing machine is based on polyolefin or the like with adjusted viscosity, added with an inorganic filler such as zeolite or glass fiber, or a foaming agent. For example, Patent Document 1 discloses a resin composition for purging a plastic molding machine containing an organopolysiloxane component. Patent Literature 2 discloses a resin composition for washing a flame-retardant resin containing borate calcium salt of higher fatty acid monoglyceride and zeolite as components. Patent Document 3 discloses a detergent comprising a mixture of 97-99% by weight of high-viscosity high-density polyethylene and 3-1% by weight of low-viscosity low-density polyethylene containing an inorganic foaming agent. Patent Document 4 describes a cleaning resin composition containing a silane-crosslinked olefin polymer and an olefin polymer as main components and used for cleaning processing machines for color change, resin change, etc. in the molding process of thermoplastic resin. things are disclosed.

JP-A-2-14247 JP-A-7-53774 JP-A-10-81898 JP-A-8-295763

The cleaning resin compositions of Patent Documents 1 to 3 do not have a sufficient cleaning effect, and in particular cannot sufficiently clean the inside of a resin processing machine after processing a silane-crosslinked polyolefin resin.

With the cleaning resin composition containing the silane-crosslinked olefin polymer of Patent Document 4 as a cleaning agent component, a cleaning effect can also be obtained in cleaning the resin processing machine after processing the silane-crosslinked polyolefin resin. In resin compositions for cleaning, the silane-crosslinked olefin polymer itself contained in the resin composition for cleaning adheres to the metal parts (screws and inner walls of flow channels) inside the resin processing machine, and in many cases, subsequent cleaning is very difficult. There was a problem of difficulty.

The present invention has been made in view of the points described in the above prior art. To provide a composition for cleaning a resin processing machine and a method for cleaning a resin processing machine, which can effectively clean a resin in a short time without causing a problem of residual resin of a detergent component in a flow path through which the resin passes. for the purpose.

As a result of intensive studies to solve the above problems, the present inventors have found that a polyolefin resin having a melt flow rate of 0.01 to 5.0 g/10 minutes (190 ° C., 2.16 kgf) and an unsaturated The inventors have found that the above problems can be solved by a resin composition containing a modified polyolefin resin graft-modified with a carboxylic acid and/or a derivative thereof, and have completed the present invention.
That is, the gist of the present invention is as follows.

[1] Graft modification with a polyolefin resin (A) having a melt flow rate (JIS-K7210, 190° C., 2.16 kgf) of 0.01 to 5.0 g/10 min and an unsaturated carboxylic acid and/or a derivative thereof. A composition for cleaning a resin processing machine containing the modified polyolefin resin (B).

[2] The resin processing machine cleaning composition according to [1], further comprising a thermoplastic elastomer (C).

[3] The composition for washing a resin processing machine according to [1] or [2], which further contains a petroleum resin (D).

[4] The composition for cleaning a resin processing machine according to any one of [1] to [3], further comprising a filler (E).

[5] The composition for washing a resin processing machine according to any one of [1] to [4], wherein the resin processing machine processes a silane-crosslinked polyolefin resin.

[6] A resin processing machine in which, after processing a silane-crosslinked polyolefin resin in a processing machine, the inside of the processing machine is washed using the composition for cleaning a resin processing machine according to any one of [1] to [5]. cleaning method.

According to the resin processing machine cleaning composition of the present invention, it is possible to effectively remove even a small amount of residual resin from the metal parts of the inner wall of the resin processing machine, and furthermore, there is the problem that the resin itself remains in the resin processing machine. Therefore, it is possible to disassemble and clean the inside of the plastic molding machine and extruder, and replace the resin in a small amount and in a short time. In particular, the composition for cleaning a resin processing machine of the present invention can obtain a high cleaning effect even for cleaning a resin processing machine after processing a silane-crosslinked polyolefin resin, which has conventionally been difficult to clean.

The present invention will be described in detail below, but the following description is an example of an embodiment of the present invention, and the present invention is not limited to the following description content as long as it does not exceed the gist of the present invention. Arbitrary modifications can be made without departing from the gist of the invention.
In addition, in the present invention, when a numerical value or a physical property value is sandwiched before and after the "~", it is used to include the values before and after it.

[Resin processing machine cleaning composition]
The resin processing machine cleaning composition of the present invention comprises a polyolefin resin (A) having a melt flow rate (JIS-K7210, 190° C., 2.16 kgf) of 0.01 to 5.0 g/10 min, and an unsaturated carboxylic acid. and a modified polyolefin resin (B) graft-modified with an acid and/or a derivative thereof.

<Olefin resin (A)>
The polyolefin resin (A) contained in the resin processing machine cleaning composition of the present invention has a melt flow rate (MFR) (JIS-K7210 190°C, 2.16 kgf) of 0.01 to 5.0 g/10 minutes. It is.

Examples of the polyolefin resin (A) include crystalline propylene homopolymer, crystalline propylene-ethylene block copolymer, crystalline propylene-ethylene random copolymer, and crystalline ethylene-propylene-butene-1 terpolymer. , crystalline propylene-butene-1 copolymer, polybutene-1, low-density polyethylene produced by the high-pressure method, linear low-density polyethylene produced using Ziegranatta catalysts, single-site catalysts, chromium-based catalysts, etc. Examples include, but are not limited to, high-density polyethylene, or mixtures of two or more thereof. Among these, polyethylene-based resins that can be extruded at low temperatures are preferable, and high-pressure low-density polyethylenes (density (JIS-K6760) of 0.930 to 0.970 g/cm ³ that have a high melt swell and are highly effective in discharging retained resin). ), and high-density polyethylene (density (JIS-K6760) of 0.910 to 0.930 g/cm ³ ).

The MFR (190° C., 2.16 kgf) of the polyolefin resin (A) is in the range of 0.01 to 5.0 g/10 minutes, preferably 0.1 to 2.0 g/10 minutes. The reason for this is that the lower the viscosity, the higher the effect of scraping out the retained resin. However, if the MFR is lower than 0.01 g/10 minutes, the resin pressure will increase, and as a result the cleaning temperature will have to be raised. On the other hand, if the MFR exceeds 5.0 g/10 minutes, the effect of scraping out the resin is reduced, which is not preferable because the cleaning effect is reduced. Here, the measurement method of MFR is according to JIS-K7210: Thermoplastic plastic flow test method (MFR).

The resin processing machine cleaning composition of the present invention may contain only one type of polyolefin resin (A), or may contain two or more types having different resin compositions and physical properties.

<Modified Polyolefin Resin (B)>
As a polyolefin resin (hereinafter sometimes referred to as "polyolefin resin (b)") to be subjected to modification of the modified polyolefin resin (B) graft-modified with an unsaturated carboxylic acid and/or a derivative thereof, , crystalline propylene homopolymer, crystalline propylene-ethylene block copolymer, crystalline propylene-ethylene random copolymer, crystalline ethylene-propylene-butene-1 terpolymer, crystalline propylene-butene-1 Copolymers, polybutene-1, low-density polyethylene produced by high-pressure processes, linear low-density polyethylene and high-density polyethylene produced using Ziegranatta catalysts, single-site catalysts, chromium-based catalysts, etc., ethylene and other than ethylene and polyolefin elastomers such as copolymers of propylene with olefins, copolymers of propylene with olefins other than propylene, or mixtures of two or more of these.

Among these, linear low-density polyethylene (density (JIS-K6760) of 0.910 to 0.930 g/cm ³ ) is preferable as the polyolefin resin (b).

The MFR (190° C., 2.16 kgf) of the polyolefin resin (b) is not particularly limited, but is preferably in the range of 0.5 to 30 g/10 min, more preferably 1 to 20 g/10 min. . If the MFR of the polyolefin resin (b) is at least the above lower limit, it is preferable from the viewpoint of maintaining extrusion characteristics such as a low motor load, and if it is at most the above upper limit, it is preferable because the extrusion characteristics of the residual resin are not impaired.

The polyolefin resin (b) and the polyolefin resin (A) described above may be the same resin or different resins, but from the viewpoint of compatibility, the same monomer component may be used. It is preferably a resin containing

The unsaturated carboxylic acid used for graft modification is preferably an α,β-ethylenically unsaturated carboxylic acid, such as acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, tetrahydrofumaric acid, itaconic acid, and citraconic acid. , crotonic acid, isocrotonic acid and the like. Examples of unsaturated carboxylic acid derivatives include acid anhydrides and carboxylic acid esters of these unsaturated carboxylic acids, and derivatives such as acid halides, amides and imides. Acid anhydrides are preferred as these derivatives. Among these, maleic acid and/or its anhydride are particularly preferred. Also, a plurality of these compounds may be used in combination.

As a method for graft modification of the polyolefin resin (b), a melt modification method can be mentioned. Specifically, a method in which the polyolefin resin (b), an unsaturated carboxylic acid and/or a derivative thereof, and, if necessary, a radical generator to be described later are mixed in advance, and then melt-kneaded in a kneader to react. , a method of adding a mixture of a radical generator and an unsaturated carboxylic acid and/or a derivative thereof to the polyolefin-based resin (b) melted in a kneader through a charging port for reaction. A Henschel mixer, a ribbon blender, a V-type blender, etc. are usually used for mixing, and a single-screw or twin-screw extruder, a roll, a Banbury mixer, a kneader, a Brabender mixer, etc. can be usually used for melt-kneading. .

Although the blending ratio of the polyolefin resin (b) and the unsaturated carboxylic acid and/or its derivative is not limited, the unsaturated carboxylic acid and/or its derivative is usually added in an amount of 0.00 to 100 parts by mass of the polyolefin resin (b). 01 to 2 parts by mass, preferably 0.05 to 1.5 parts by mass. If the blending ratio of the unsaturated carboxylic acid and/or derivative thereof is equal to or less than the above upper limit, residual unreacted unsaturated carboxylic acid can be suppressed, and defects such as burning can be prevented. Moreover, if it is more than the said minimum, the cleaning effect of the resin processing machine washing|cleaning composition obtained by ensuring the modification|denaturation amount can be improved.

Radical generators are not limited, but specific examples include benzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxybenzoate)hexyne-3, lauroyl Peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butyl perbenzoate , tert-butyl perisobutyrate, tert-butyl perpivalate, and cumyl perpivalate, and other organic peroxides and organic peresters, or azo compounds such as azobisisobutyronitrile and dimethylazoisobutyrate. etc. can be used.

These radical generators can be appropriately selected according to the type of polyolefin resin (b) as a raw material, the type of MFR, the unsaturated carboxylic acid and/or its derivative, the reaction conditions, etc. You may

Although the amount of the radical generator to be blended is not limited, it is usually 0.001 to 5 parts by mass, preferably 0.005 to 3 parts by mass, per 100 parts by mass of the polyolefin resin (b). If the blending ratio of the amount of radical generation is below the above upper limit, it is possible to suppress the influence on the molecular weight and prevent adverse effects on the extrusion properties and adhesiveness. It is possible to secure the graft amount and prevent problems such as burning.

The amount of modification (grafting ratio) by the unsaturated carboxylic acid and/or derivative thereof in the modified polyolefin resin (B) is not limited, but is usually 0.01% by mass or more, preferably 0.1% by mass or more, and more preferably 0. .3% by mass or more, and 1.5% by mass or less, preferably 1.2% by mass or less, and more preferably 1% by mass or less. If the amount of modification by the unsaturated carboxylic acid and/or derivative thereof is at least the above lower limit, the cleaning performance of the cleaning resin composition of the present invention can be enhanced, and if it is below the above upper limit, the thermal stability is lowered. can be prevented and the amount of unreacted unsaturated carboxylic acid can be suppressed to prevent problems such as burning.

Here, the modified amount (graft ratio) means the content of the unsaturated carboxylic acid and/or its derivative component when measured with an infrared spectrometer. For example, absorption specific to unsaturated carboxylic acids and/or derivatives thereof in a sample press-molded into a sheet with a thickness of about 100 μm, specifically 1,900 to 1,600 cm ⁻¹ (C=O stretching vibration band) can be determined by measuring the absorption specific to the carbonyl group of (the same applies to the following description). In the modification with an unsaturated carboxylic acid and/or a derivative thereof, 100% of the unsaturated carboxylic acid and/or derivative thereof that has not reacted with the polyolefin resin (b) without being subjected to the reaction is also a modified polyolefin resin. Although it may remain in (B), the modified amount (graft ratio) in the present invention means the value measured by the above method.

The resin processing machine cleaning composition of the present invention may contain only one modified polyolefin resin (B), and the composition and physical properties of the polyolefin resin (b), the unsaturated carboxylic acid used for modification, and the And/or it may contain two or more kinds of derivatives or different amounts of modification thereof.

<Contents of polyolefin resin (A) and modified polyolefin resin (B)>
In the resin processing machine cleaning composition of the present invention, the contents of the polyolefin resin (A) and the modified polyolefin resin (B) are the polyolefin resin (A) and the modified polyolefin resin (B), and optionally Polyolefin resin (A) is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, preferably 1 to 10 parts by mass, more preferably 3 to 8 parts by mass of the modified polyolefin resin (B), and the total amount of the polyolefin resin (A) and the modified polyolefin resin (B) is 100. It is preferable that the proportion of the polyolefin resin (A) in the mass % is 60 to 90 mass % and the proportion of the modified polyolefin resin (B) is 10 to 40 mass %. By including the polyolefin resin (A) and the modified polyolefin resin (B) in the above range, a good cleaning effect is exhibited.

<Thermoplastic elastomer (C)>
The composition for washing a resin processing machine of the present invention may contain a thermoplastic elastomer (C), and by containing the thermoplastic elastomer (C), the washing effect can be further enhanced.

The thermoplastic elastomer (C) may be an ethylene-based elastomer obtained by copolymerizing ethylene and one or more olefins having 3 or more carbon atoms, or one or more propylene and ethylene or olefins having 4 or more carbon atoms. propylene elastomer, polybutadiene, polyisoprene, butyl rubber, styrene-butadiene copolymer, styrene-isoprene copolymer, acrylonitrile-butadiene copolymer, ethylene-α-olefin copolymer, ethylene-α- Olefin-polyene copolymer, silicone rubber, acrylic rubber, butadiene-(meth)acrylate copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenated styrene-ethylene -butylene-styrene block copolymers, hydrogenated styrene-ethylene-propylene-styrene block copolymers, ethylene-based ionomers, etc., but not limited thereto.
In particular, styrene-based styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), hydrogenated styrene-ethylene-butylene-styrene block copolymer (SEBS), hydrogenated styrene Ethylene-propylene-styrene block copolymer (SEPS), ethylene-based elastomers, and propylene-based elastomers are preferred because they have high affinity with the base resin and are easy to extrude.

These thermoplastic elastomers (C) may be used alone or in combination of two or more.

The thermoplastic elastomer (C) is generally not compatible with the base resin and the silane-crosslinkable polyolefin of the resin processing machine cleaning composition of the present invention, but has a high affinity and behaves elastically when melted. For this reason, it is thought to have the effect of entangling the object to be cleaned even during cleaning, increasing the friction with the flowing resin, and scraping out the remaining resin. For these reasons, a material with a viscosity as high as possible is preferable, and the melt flow rate (MFR) (JIS-K6760, 190° C., 2.16 kgf) of the thermoplastic elastomer (C) is 0.5 to 10 g/10 minutes, In particular, it is preferably 0.5 to 5 g/10 minutes. If the MFR of the thermoplastic elastomer (C) is at least the above lower limit, it is preferable from the viewpoint of maintaining extrusion properties such as a low motor load.

When the resin processing machine cleaning composition of the present invention contains a thermoplastic elastomer (C), the content thereof is the polyolefin resin (A), the modified polyolefin resin (B), the thermoplastic elastomer (C), and the necessary Preferably 5 to 40 parts by mass, more preferably 20 to 40 parts by mass in a total of 100 parts by mass of the petroleum resin (D) and filler (E) to be blended according to the polyolefin resin It is preferably 5 to 200 parts by mass, particularly preferably 50 to 150 parts by mass, per 100 parts by mass of (A) and modified polyolefin resin (B).
If the content of the thermoplastic elastomer (C) is at least the above lower limit, it is possible to reliably obtain the effect of improving the cleaning effect due to the addition of the thermoplastic elastomer (C). On the other hand, if the content of the thermoplastic elastomer (C) is equal to or less than the above upper limit, it is possible to prevent the deterioration of the cleaning effect due to the remaining thermoplastic elastomer (C) phase-separated itself.

<Petroleum resin (D)>
The composition for cleaning a resin processing machine of the present invention may further contain a petroleum resin (D), and the cleaning effect can be further enhanced by containing the petroleum resin (D).

The petroleum resin (D) used in the present invention includes, for example, aliphatic petroleum resins, aromatic petroleum resins, copolymers thereof, and hydrogenated products thereof. The skeleton of the petroleum resin includes C5 (carbon number 5) resin, C9 (carbon number 9) resin, C5/C9 copolymer resin, cyclopentadiene resin, polymer of vinyl-substituted aromatic compound, olefin/vinyl-substituted aromatic copolymers of group compounds, copolymers of cyclopentadiene-based compounds/vinyl-substituted aromatic compounds, and hydrogenated products thereof.

The rosin resin is a natural resin containing abietic acid as a main component. Examples include natural rosin, polymerized rosin derived from natural rosin, and stabilized rosin obtained by disproportionating or hydrogenating natural rosin or polymerized rosin. , unsaturated acid-modified rosin obtained by adding unsaturated carboxylic acids to natural rosin or polymerized rosin, natural rosin ester, modified rosin ester, polymerized rosin ester, and the like.

Examples of the terpene resin include polyterpene resins, aromatic terpene resins such as terpene phenol resins, aromatic modified terpene resins, and hydrogenated products thereof.

These petroleum resins (D) have good fluidity when fluidized at high temperatures, penetrate well into stagnant resin, and have a high affinity with the polyolefin resin used as the base resin, so they can be extruded without phase separation. Therefore, it is considered that it particularly contributes to the cleaning effect.

These petroleum resins (D) may be used alone or in combination of two or more.

When the composition for washing a resin processing machine of the present invention contains a petroleum resin (D), the content thereof is a polyolefin resin (A), a modified polyolefin resin (B) and a petroleum resin (D), and if necessary It is preferably 5 to 20 parts by mass, more preferably 10 to 20 parts by mass, in a total of 100 parts by mass of the thermoplastic elastomer (C) and the filler (E) described later, which are blended in the polyolefin-based It is preferably 5 to 100 parts by mass, particularly preferably 20 to 70 parts by mass, per 100 parts by mass of resin (A) and modified polyolefin resin (B).
If the content of the petroleum resin (D) is at least the above lower limit, it is possible to reliably obtain the effect of improving the cleaning effect by blending the petroleum resin (D). On the other hand, when the content of the petroleum resin (D) is equal to or less than the above upper limit, it is possible to suppress a decrease in the viscosity of the composition for washing a resin processing machine and prevent a reduction in the scraping effect.

<Filler (E)>
The resin processing machine cleaning composition of the present invention may further contain a filler (E), and the inclusion of the filler (E) imparts a scraping effect to further enhance the cleaning effect. can.

Fillers (E) are roughly classified into organic fillers and inorganic fillers. Examples of organic fillers include acrylic beads, cellulose fine particles, wood flour, naturally derived polymers such as bean curd refuse, rice husks, bran, and modified products thereof. Inorganic fillers include talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, and carbon. Black, zinc oxide, antimony trioxide, zeolite, montmorillonite, metal fibers, metal whiskers, ceramic whiskers, potassium titanate, boron nitride, graphite, carbon fibers and the like. Among these, inorganic fillers such as talc, calcium carbonate, silica, zeolite, and glass fiber are preferred because they leave little residue after washing.
These fillers (E) may be used alone or in combination of two or more.

When the composition for washing a resin processing machine of the present invention contains a filler (E), its content is the polyolefin resin (A), the modified polyolefin resin (B) and the filler (E), and if necessary Preferably 5 to 30 parts by mass, more preferably 10 to 25 parts by mass, in a total of 100 parts by mass of the thermoplastic elastomer (C) and petroleum resin (D) blended in the above, and the polyolefin resin ( It is preferably 5 to 140 parts by mass, particularly preferably 50 to 120 parts by mass, per 100 parts by mass of A) and modified polyolefin resin (B).
If the content of the filler (E) is at least the above lower limit, the effect of improving the cleaning effect due to the scraping effect due to the blending of the filler (E) can be reliably obtained. On the other hand, if the content of the filler (E) is equal to or less than the above upper limit, it is possible to prevent a decrease in fluidity.

<Other ingredients>
In addition to the components described above, the cleaning resin composition of the present invention may contain other optional additives, resins, etc. (hereinafter referred to as "other components ) can be blended. The other components may be used alone or in combination of two or more in any combination and ratio.

Additives include auxiliary additives generally used in polyolefin resin compositions, specifically antioxidants, neutralizers, processing aids, plasticizers, crystal nucleating agents, impact modifiers, flame retardants. , flame retardant aids, cross-linking agents, cross-linking aids, antistatic agents, lubricants, surfactants, fillers, compatibilizers, heat stabilizers, weather stabilizers (antioxidants, light stabilizers, UV absorbers, etc.) ), antifog agents, slip agents, antiblocking agents, antibacterial agents, coloring agents (pigments, dyes, etc.), and the like.
Among these, antioxidants and neutralizers are generally used, and it is preferable to add them to the cleaning resin composition from the viewpoint of suppressing deterioration of the resin.

In addition, from the viewpoint of assisting the cleaning effect, it is also possible to add components known as detergent components, such as lubricants, antistatic agents, surfactants, and antifogging agents.

In addition, as cleaning auxiliary ingredients, additives generally used as foaming agents, such as sodium hydrogen carbonate (sodium bicarbonate), inorganic foaming agents such as alkali metal hydrogen carbonate such as potassium hydrogen carbonate, organic foaming agents such as citric acid By blending the agent, the replacement efficiency of the residual resin can be enhanced. The reason for this is thought to be that the carbon dioxide generated by thermal decomposition floats the retained resin, thereby increasing the cleaning effect. Among these, an inorganic foaming agent such as sodium bicarbonate having a low decomposition temperature is preferable. The blending ratio of the foaming agent is 0.1 to 5 parts by mass, preferably 0.5 to 3 parts by mass, per 100 parts by mass of the cleaning resin composition. If the blending ratio of the foaming agent is at least the above lower limit, a sufficient cleaning assistance effect can be obtained by blending the foaming agent. It is possible to suppress harmful effects such as odor and odor.

<Manufacturing method>
The blending method for producing the resin processing machine cleaning composition of the present invention using the above-mentioned essential components and other components that are added as necessary includes a melting method, a solution method, a suspension dispersion method, and the like. Yes, but not particularly limited. Practically, the melt-kneading method is preferred.

As a specific method for melt-kneading, powdery or granular components and other components that are added as necessary are mixed in a predetermined mixing ratio using a Henschel mixer, a ribbon blender, a V-type blender, or the like. For example, after mixing them uniformly using a common kneader such as a Banbury mixer, a kneader, a roll, or a multi-screw kneading extruder such as a single or twin screw.

The melt-kneading temperature of each component is usually in the range of 100 to 300°C, preferably in the range of 120 to 280°C, particularly preferably in the range of 150 to 250°C. Furthermore, the kneading order and method of each component are not particularly limited, and polyolefin resin (A), modified polyolefin resin (B), thermoplastic elastomer (C), petroleum resin (D), filler ( A method of collectively kneading E) and other components used as necessary, or a polyolefin resin (A), a modified polyolefin resin (B), a thermoplastic elastomer (C), a petroleum resin (D), A method of pre-kneading the filler (E) and a part of other components used as necessary and then kneading the remaining components may be used. It is also possible to separately prepare the above compositions and use them for washing in the form of a dry blend.

[Washing method for resin processing machine]
Examples of resin processing machines to which the cleaning resin composition of the present invention is applied include ordinary kneading extruders, injection molding machines for obtaining molded articles, extrusion molding machines, and the like. A general kneader is a single-screw or twin-screw extruder for blending and melt-kneading raw materials. Examples of injection molding machines include general injection molding machines, and examples of extrusion molding machines include blow molding machines, inflation molding machines, and extruders with dies such as T dies and pipe dies.

The temperature of the resin during cleaning with the resin processing machine cleaning composition of the present invention is 160 to 250°C, preferably 180 to 230°C. If the resin temperature is equal to or higher than the above lower limit, the resin can be sufficiently plasticized to prevent damage to the device. Further, if the resin temperature is equal to or lower than the above upper limit, it is possible to prevent burning of the retained resin and obtain a good cleaning effect.

As a method for cleaning a resin processing machine such as a molding machine or an extruder, after removing the remaining preceding resin from the hopper of the resin processing machine to be cleaned, the composition for cleaning the resin processing machine of the present invention is put into the hopper, The resin processing machine such as a molding machine or an extruder may be operated under the molding conditions of the preceding resin, or the resin processing machine such as a molding machine or an extruder may be operated at the temperature settings described above, and after sufficiently scraping out the remaining resin, the resin processing machine cleaning composition may be discharged. , or by replacing it with a normal purge material and converting it again into the subsequent material.
The cleaning of the resin processing machine can also be carried out including the metal molds, dies, and the like.
In the case of disassembly cleaning, especially after cleaning with the resin processing machine cleaning composition of the present invention, high density polyethylene or a commonly sold purge material (for example, "Super Clean" manufactured by Nitto Kako Co., Ltd.). By lightly purging and then disassembling and cleaning, the subsequent cleaning efficiency of the screw and the like is greatly improved.

The composition for cleaning a resin processing machine of the present invention has an extremely high cleaning effect, and can be used for cleaning a resin processing machine after processing a silane-crosslinked polyolefin resin, which has been difficult to clean with conventional compositions for cleaning a resin processing machine. You can also get a good cleaning effect.

Specific embodiments of the present invention will be described in more detail below using examples, but the present invention is not limited by the following examples as long as the gist thereof is not exceeded. Various production conditions and values of evaluation results in the following examples have the meaning of preferred values of the upper limit or the lower limit in the embodiments of the present invention, and the preferred range is the above-described upper limit or lower limit value. , the range defined by the values in the following examples or a combination of the values in the examples.

[Materials used]
Materials used in the following examples and comparative examples are as follows.
<Polyolefin resin (A)>
High-pressure low-density polyethylene “YF30” manufactured by Nippon Polyethylene Co., Ltd. (MFR: 1.1 g/10 minutes, density: 0.920 g/cm ³ )

<Other polyolefin resin (a)>
High-pressure low-density polyethylene “LC600A” manufactured by Nippon Polyethylene Co., Ltd. (MFR: 7 g/10 min, density: 0.918 g/cm ³ )

<Modified Polyolefin Resin (B)>
A modified polyolefin resin (B) produced by the following method was used.
Japan Polyethylene Co., Ltd. Linear low-density polyethylene "UF240" (MFR: 2.1 g / 10 minutes) 100 parts by mass, maleic anhydride (Nippon Shokubai) 1 part by mass, NOF Corporation organic peroxide (perbutyl D ) are dry-blended, then kneaded in a twin-screw extruder heated to 230° C. for graft modification to obtain a modified polyethylene having a graft ratio of 1% by weight, which is a modified polyolefin resin (B ).

<Thermoplastic elastomer (C)>
Mitsui Chemicals ethylene-butene elastomer “Tafmer A1085A” (MFR: 1.2 g/10 min, density: 0.885 g/cm ³ )

<Petroleum resin (D)>
Alicyclic saturated hydrocarbon resin “Arcon P125” (softening point: 125 ° C.) manufactured by Arakawa Chemical Industries, Ltd.

<Filler (E)>
Talc "PKP53S" manufactured by Fuji Talc Co., Ltd.

<Blowing agent>
Wako Pure Chemical Baking Soda

[Example 1]
Raw materials were prepared according to the formulation of Example 1 shown in Table 1, and melt-kneaded at 160° C. with a single-screw extruder (manufactured by IKG, 50 mm) to produce a composition for washing a resin processing machine.

Using a pipe molding machine in which a pipe-shaped single layer die (outer diameter 13 mm, inner diameter 9.8 mm) is connected to a single shaft 50 mm, a silane crosslinked polyolefin resin composition ("Linklon XLE830N" manufactured by Mitsubishi Chemical Co., Ltd. and Mitsubishi Chemical Co., Ltd. Co., Ltd. catalyst masterbatch "HZ089" at a mixing mass ratio of 100:5) is run at 200 ° C. at a rotation speed of 80 rpm (about 15 kg / hour) for 1 hour, and then the resin processing machine washing manufactured above The composition was washed under the same conditions for 10 minutes (about 3 kg). After that, the resin was drained and the apparatus was disassembled for cleaning. When the silane-crosslinked polyolefin resin remains, it can be easily distinguished from the purge material composed of the resin processing machine cleaning composition of the present invention in terms of hue. Although the substance can be easily peeled off from the channel wall, the silane-crosslinked polyolefin resin is difficult to peel off even if it is rubbed with a copper brush or the like.

The remaining state of the silane-crosslinked polyolefin resin in the screw and the flow path inside the die was evaluated as follows.
Good: Almost no silane-crosslinked polyolefin-based resin remains, and there is no burning or the like. Adhesive resin can be removed immediately by cleaning even if it remains.
Δ: The silane-crosslinked polyolefin resin remains, but there is no burning or the like. Adhered resin can be removed immediately by lightly rubbing with a brush.
x: Silane-crosslinked polyolefin-based resin, scorch, etc. remain, and adhered resin, scorch, etc. must be thoroughly rubbed with a brush to remove them.

[Example 2, Comparative Examples 1 to 4]
A composition for cleaning a resin processing machine was produced in the same manner as in Example 1 using the formulations shown in Table 1, and the cleaning effect was evaluated in the same manner. Table 1 shows the results.

From Table 1, it can be seen that the resin processing machine cleaning composition of the present invention is excellent in the cleaning effect of the resin processing machine.

On the other hand, Comparative Example 1 that does not contain the modified polyolefin resin (B), Comparative Example 3 that uses the polyolefin resin (a) with a high MFR, and Comparative Example 4 that uses only the polyolefin resin (A) , the cleaning effect is very poor.
Comparative Example 2 does not use the modified polyolefin resin (B), and although the cleaning effect is slightly higher than the other Comparative Examples, it is not sufficient.
As described above, by using the composition for washing a resin processing machine of the present invention, it is possible to obtain a good cleaning effect particularly for a resin processing machine for silane-crosslinked polyolefin-based resins, and the decomposition of plastic molding machines and extruders can be prevented. It can be seen that cleaning and resin replacement can be performed in a small amount and in a short time.

Claims (5)

A polyolefin-based resin (A) having a melt flow rate (JIS-K7210, 190°C, 2.16 kgf) of 0.01 to 5.0 g/10 min, and a modified graft modified with an unsaturated carboxylic acid and/or a derivative thereof. A composition for washing a resin processing machine containing a polyolefin resin (B) , a thermoplastic elastomer (C) and a petroleum resin (D) . The content of the thermoplastic elastomer (C) is 5 to 200 parts by mass with respect to the total of 100 parts by mass of the polyolefin resin (A) and the modified polyolefin resin (B), and the content of the petroleum resin (D) is 5 to 100 parts by mass, the resin processing machine cleaning composition according to claim 1. 3. The composition for washing a resin processing machine according to claim 1 , further comprising a filler (E). The composition for washing a resin processing machine according to any one of claims 1 to 3 , wherein the resin processing machine is a processing machine for processing a silane-crosslinked polyolefin resin. A method for cleaning a resin processing machine, comprising processing a silane-crosslinked polyolefin resin in a processing machine and then cleaning the inside of the processing machine using the composition for cleaning a resin processing machine according to any one of claims 1 to 4 .