JP4919513B2 - Detergent composition for molding machine - Google Patents

Description

  The present invention relates to a cleaning composition for cleaning the inside of a molding machine for thermoplastic resins.

  In general, a molding machine (extrusion / injection) is used for the purpose of coloring, mixing, molding, etc. of the resin. The agent remains in the molding machine. This residue is mixed into the molded product at the time of the next molding with the different color resin, and causes a product appearance defect.

  Conventionally, in order to remove the residue from the molding machine, the molding machine is manually disassembled and cleaned, and the molding machine is filled with the molding material to be used next without stopping the molding machine. A method of gradually replacing and a method using a cleaning agent have been implemented.

  When using a cleaning agent, after washing with the cleaning agent and before starting the next molding, the remaining cleaning agent is usually replaced with the next molding material. Therefore, the cleaning agent is required to have a high detergency for the molding material used in the previous molding and easy replacement by the molding material used in the next molding.

  The present inventors have already disclosed a cleaning agent comprising a styrene-based resin and a specific graft polymer as a cleaning agent having excellent cleaning performance and easy replacement, and further contains glass fibers or glass particles in the cleaning agent. (Patent Document 1). However, when the cleaning agent contains glass fibers or glass grains, depending on the type of molding machine, there is a problem that the glass fibers or glass grains may damage the inside of the molding machine during cleaning or clog the filter part of the molding machine. there were.

  A detergent composition containing 0.5 to 20 parts by weight of a fluorinated polymer and / or an acid or acid anhydride-modified polymer with respect to 100 parts by weight of a mixture containing a thermoplastic resin and wollastonite (Patent Document 2) ) Has also been proposed, but in recent efforts to conserve resources, there has been a demand for further improvement of easy replacement (non-residuality) in the molding machine. However, the above-described cleaning agent is required to further improve the adhesion of the cleaning agent itself to the screw in the molding machine and easy replacement after the molding material in the molding machine is cleaned. In particular, although a cleaning composition containing an inorganic filler has high cleaning performance, it tends to remain in the molding machine, and thus has a drawback that transparency is easily hindered when the next molding material is a transparent resin. Due to the recent increase in awareness of environmental issues such as resin recycling and reduction of materials used, there is a strong market demand to minimize resin loss during cleaning, and it has excellent cleaning performance, and there is little residue in the molding machine. There is a need for easily replaceable detergent compositions.

JP-A-5-42547 JP 2004-107433 A

  An object of the present invention is to obtain a cleaning composition having excellent cleaning performance and easy replacement (non-residual) for molding machine cleaning in order to satisfy such recent market demand for resource saving.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that 100 parts by weight of the thermoplastic resin (A) is 0.10 parts by weight of the thermoplastic resin (A) incompatible with the thermoplastic resin (B) The present inventors have found that a cleaning composition for a molding machine containing 5 to 30 parts by weight and a fluorinated polymer has excellent detergency as well as excellent cleaning performance, and reached the present invention.

(1) At least one resin selected from the group consisting of styrene-based resins, polyolefin-based resins, methacrylic acid-based resins and polycarbonate-based resins, and has a melt flow rate of 0.5 to 30 g / 10 minutes (220 ° C. · 10 kg) And 100 parts by weight of the first thermoplastic resin (A) and at least one resin selected from the group consisting of polyolefin resins and styrene resins that are incompatible with the thermoplastic resin (A), An incompatible resin mixture containing 0.5 to 10 parts by weight of a second thermoplastic resin (B) having a flow rate of 0.5 to 30 g / 10 minutes (220 ° C., 10 kg), and a fluorinated polymer A cleaning composition for a molding machine.
(2) The cleaning composition for a molding machine according to (1), wherein 0.5 to 20 parts by weight of a fluorinated polymer is contained with respect to 100 parts by weight of the incompatible resin mixture.
(3) One of the first thermoplastic resin (A) and the second thermoplastic resin (B) is a polyolefin resin, and the other is a styrene resin (1) or ( The cleaning composition according to 2).
(4) The cleaning composition for a molding machine according to any one of (1) to (3), wherein the fluorinated polymer is an acrylic resin-modified polytetrafluoroethylene.
(5) The molding machine according to any one of (1) to (4), comprising at least one selected from the group consisting of an inorganic filler, an acid or acid anhydride modified polymer, and mineral oil. Detergent composition.
(6) The cleaning composition for a molding machine according to any one of (1) to (5), wherein 0.1 to 10% by mass of water is contained.

  A fluorinated polymer is added to an incompatible resin mixture containing 100 to 30 parts by weight of the thermoplastic resin (A) and 0.5 to 30 parts by weight of the thermoplastic resin (B) incompatible with the thermoplastic resin (A). The cleaning composition of the present invention shown in the contained examples requires a small amount of the cleaning composition in the cleaning of the molding material, and particularly the cleaning composition itself with a small amount of resin used in the replacement injection operation (B). The cleaning composition was excellent in cleaning performance and easy replacement (non-residual).

Hereinafter, the present invention will be described in detail.
The cleaning composition of the present invention contains 100 parts by weight of the thermoplastic resin (A) and 0.5 to 30 parts by weight of the thermoplastic resin (A) and the incompatible thermoplastic resin (B). Contains a resin mixture and a fluorinated polymer.
The reason why this composition exhibits excellent cleaning performance and easy substitution is not clear, but in the coexistence state of the incompatible resin mixture and the fluorinated polymer, it is washed from the separated state of each component in the cylinder of the molding machine. It is considered that the agent composition is easily discharged from the molding machine and exhibits a high ease of replacement.

  As the first and second thermoplastic resins (A) and (B), resins used for injection molding, extrusion molding and the like can be widely used. Specific examples include styrene resins such as polystyrene, ethylene resins such as polyethylene, propylene resins such as polypropylene, methacrylic ester resins such as polymethyl methacrylate, polyvinyl chloride, polyamide resins, polycarbonate, and polybutene. Is mentioned. Of these, styrene resins and polyolefin resins are preferred.

  Styrenic resin refers to polystyrene or a copolymer of styrene and one or more other monomers, and has a styrene content of 50% by mass or more. Examples of other monomers copolymerized with styrene include acrylonitrile and butadiene. Specific examples of the styrene resin include polystyrene, styrene-acrylonitrile copolymer, and styrene-butadiene-acrylonitrile copolymer. Among these, a styrene-acrylonitrile copolymer is preferable from the viewpoint of cleaning performance and non-residence in the molding machine, and a styrene-acrylonitrile copolymer having an acrylonitrile content of 5% by mass to 50% by mass is particularly preferable.

  The molecular weights of the first and second thermoplastic resins (A) and (B) are not particularly limited, but 200,000 to 300,000 are preferable. Moreover, it is preferable that the melt flow rate is 0.5-30 g / 10min, More preferably, it is 0.5-10g / 10min. When the melt flow rate is less than 0.5 g / 10 min, it is difficult to use at standard molding conditions such as a molding temperature of 200 to 280 ° C., and when it exceeds 30 g / 10 min, it is difficult to obtain a sufficient cleaning effect. In addition, the melt flow rate in this specification means the value in 220 degreeC and 10 kg conditions.

  The polyolefin-based resin is a polyethylene-based resin, a polypropylene-based resin, and the like, and includes a copolymer resin of ethylene, propylene, and α-olefin. Among these, a polypropylene resin containing polypropylene and a propylene copolymer is preferable because of excellent cleaning performance and non-residence in the molding machine.

The second thermoplastic resin (B) is a resin that is incompatible with the first thermoplastic resin (A). In the present specification, the “incompatible resin with the first thermoplastic resin (A)” means a resin that forms two phases by phase separation when mixed with the first thermoplastic resin (A). .
Specific examples of the thermoplastic resin (A) / thermoplastic resin (B) combination include styrene resin / polyolefin resin and polyolefin resin / styrene resin. Preferred examples include polystyrene / polypropylene, polystyrene / polyethylene, styrene-acrylonitrile copolymer / polypropylene, and polyethylene / styrene-acrylonitrile copolymer.

  The mixing ratio of the thermoplastic resin (A) and the thermoplastic resin (B) is 0.5 to 30 parts by weight, preferably 1 to 10 parts by weight with respect to 100 parts by weight of the thermoplastic resin (A). Part content. When the amount of the thermoplastic resin (B) is 30 to 100 parts by weight with respect to 100 parts by weight of the thermoplastic resin (A), the cleaning performance and the easily replaceability (non-residuality) are lowered. The reason is not clear, but it may be because the melt viscosity is improved too much.

  Examples of the fluorinated polymer include polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer, and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer. Particularly preferred is polytetrafluoroethylene modified with an acrylic resin. Fluoroethylene and its copolymer. By modifying the acrylic resin, not only the cleaning performance and easy replacement of the cleaning composition are greatly improved, but also the effect of suppressing the generation of fine powder in the cleaning composition is exhibited. The reason is not clear, but may be related to subtle compatibility with other ingredients in the cleaning composition.

  From the viewpoint of obtaining good cleaning performance, the content of the fluorinated polymer is fluorinated heavy with respect to 100 parts by weight of the incompatible resin mixture composed of the first and second thermoplastic resins (A) and (B). The combined content is preferably 0.5 to 20 parts by weight, more preferably 0.5 to 5 parts by weight.

Furthermore, at least 1 sort (s) selected from the group which consists of an inorganic filler, an acid or an acid anhydride modified polymer, and mineral oil can also be contained. Examples of inorganic fillers include calcium carbonate, magnesium carbonate, titanium oxide, talc, aluminum hydroxide, magnesium hydroxide, zeolite, mica, diatomaceous earth, glass powder, glass sphere, shirasu balloon, quec sand and wollastonite. It is done.
The cleaning composition of the present invention has an effect that it does not easily remain in the molding machine even if it contains an inorganic filler, but the portion where the resin stays like the T-die of an extrusion molding machine or the accumulator of a blow molding machine It may be better not to use an inorganic filler depending on the structure to be cleaned, such as a molding machine having a structure.

Examples of the acid or acid anhydride-modified polymer include polyolefin resins or styrene resins modified with an acid or acid anhydride, and those modified with carboxylic anhydride are preferable. Examples of preferred acids or anhydrides include acrylic acid, methacrylic acid, and maleic anhydride.
Content of an acid or an acid anhydride is 1-20 mass% in a modified polymer, Preferably it is 5-15 mass%. In particular, a modified polymer having a higher acid or acid anhydride content than a normal modified polymer is preferred. A preferable example is a carboxylic anhydride group-modified low molecular weight polypropylene “Yumex 1010” commercially available from Sanyo Chemical Co., Ltd.

  Mineral oil is oil obtained by refining petroleum, and is saturated hydrocarbon oil containing mineral oil, lubricating oil, naphthene, which is also called liquid paraffin, and isoparaffin. Oils with a wide viscosity range can be used, and liquid paraffin having a JIS range of 50 seconds to 500 seconds and an ISO viscosity range of 15 to 100 may be used. The content of mineral oil is preferably 10 parts by weight or less from the viewpoint of obtaining excellent cleaning performance with respect to 100 parts by weight of the resin mixture constituting the cleaning composition, and 0 from the viewpoint of easy replacement (non-residual). 1 part by weight or more is preferable.

  The present detergent composition may contain an ultra high molecular weight polymer. The molecular weight of the ultra-high molecular weight polymer is approximately 1 million or more. Examples of the ultra high molecular weight polymer include ethylene super polymer, styrene-acrylonitrile super polymer, and methyl methacrylate super polymer. By adding an ultra high molecular weight polymer, a high detergency can be obtained without using glass fibers or inorganic substances. Further, when the cleaning agent after use is disposed of by incineration, there is an advantage that no residue remains unlike the case of containing glass fibers or inorganic substances. The addition amount is preferably 2 to 50 parts by weight with respect to 100 parts by weight of the present cleaning composition. It is preferable to knead the ultra high molecular weight polymer in advance in the resin constituting the cleaning composition because the effect of improving the cleaning power is great.

The present detergent composition may contain, as a lubricant, an alkali metal salt or an alkaline earth metal salt, particularly a stearic acid metal salt such as magnesium stearate. When a lubricant such as an alkali metal salt is contained, the cleaning composition is less likely to remain, and even if it remains, removal is facilitated. The addition amount of the alkali metal salt is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin constituting the cleaning composition.
It is preferable to knead the alkali metal salt in advance with a resin constituting the cleaning composition because the effect is large.

Moreover, since a cleaning performance improves when a cleaning composition contains a foaming agent, it is preferable. The foaming agent may be an inorganic foaming agent such as sodium bicarbonate or ammonium carbonate, or an organic foaming agent such as azodicarbonamide or azobisisobutyronitrile. The addition amount of the foaming agent is preferably 0.1 to 4 parts by weight with respect to 100 parts by weight of the present cleaning composition, and particularly preferably added in combination with the alkali metal salt or alkaline earth metal salt.
It is preferable that the foaming agent is kneaded in advance with the resin constituting the cleaning agent because the effect is large.

Moreover, it is preferable that this cleaning composition contains a water | moisture content. This moisture becomes steam in the molding machine and effectively acts to peel off the residue.
When moisture is contained, for example, by adsorbing moisture to the resin constituting the present cleaning composition, or by enclosing water inside the resin constituting the present cleaning composition as a porous material, It is preferable to prevent water from being removed to the outside at the time of charging. The amount of water to be contained is preferably 0.1% by mass or more from the viewpoint of exerting a sufficient effect for peeling off the residue, and from the viewpoint of preventing water from leaving the cleaning agent and remaining in the molding machine. 10 mass% or less is preferable.

  The shape of the cleaning composition is not limited. For example, in order to produce pellets made of a detergent composition, an extruder is used to extrude the first thermoplastic resin (A), the second thermoplastic resin (B), and the fluorinated polymer, and if necessary, other components. It is preferable to melt-knead and form a pellet.

  Excellent cleaning performance in the feed zone when the diameter or length of the pellet (average value of major axis and minor axis) is 40 to 100%, preferably 60 to 100% with respect to the screw groove depth of the molding machine feed zone And easy replacement can be obtained. Particularly, it can be suitably used for a large molding machine, specifically, a large molding machine having a screw diameter of 70 mm or more and a feed groove screw groove depth of 10 mm or more.

  If the diameter or length of the pellet is less than 40% with respect to the screw groove depth of the molding machine feed zone, it tends to be difficult to obtain sufficient detergency and easy replacement, and the diameter of the pellet exceeds 100%. Or, when the length exceeds 100%, there is a tendency that the screw is insufficiently bitten and the inside of the cylinder may be damaged.

  The content of pellets of the above size is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, from the viewpoints of detergency and easy replacement. It is preferable that the fine powder is not substantially contained in the cleaning composition.

The cleaning composition comprising this cleaning composition is put into a molding machine and has a cleaning effect by operating the molding machine almost normally, and is particularly effective for injection molding machines and extrusion molding machines. Similarly to these, any apparatus having a cylinder portion that heats and melts a resin to knead can be widely applied.
When the cleaning agent comprising the cleaning composition is used in a molding machine with a vent, a preferable result can be obtained by adding a part of the cleaning agent from the vent port.

It is preferable to set the operating conditions of the molding machine in the case of using the cleaning composition comprising the present cleaning composition so as to increase the internal pressure of the cylinder since the effect becomes more remarkable. That is, it is preferable to perform operations such as lowering the cylinder temperature within a dischargeable range, applying a back pressure, and injecting at a high speed.
Next, the present invention will be described by examples.

The molding machine used, molding temperature and measurement conditions in Examples and Comparative Examples are shown below.
(1) Molding machine An inline screw type injection molding machine (with a clamping force of 125 tons and a capacity of 10 ounces) was used.
(2) Molding temperature Cylinder temperature: 240 ° C
(3) Melt flow rate (MFR)
It measured by 220 degreeC and 10 kg load by JIS-K7210.

[Examples 1-5, Comparative Examples 1-3]
<Manufacture of cleaning composition>
Styrene-acrylonitrile resin (AS) <Stylac, MFR 2 g / 10 min>, Polypropylene resin (PP) <Sun Allomer, MFR 7 g / 10 min>, Acrylic resin-modified polytetrafluoroethylene <Metbrene A manufactured by Mitsubishi Rayon Co., Ltd. -3000 ">, mineral oil (MO) <Demitsu Kosan Co., Ltd. Diana Process Oil PW-90>, acid anhydride group-modified low molecular weight polypropylene <" Yumex 1010 "manufactured by Sanyo Chemical Industries Ltd.> Then, the mixture was melt-kneaded using an extruder and the strand was cooled with cooling water, and then cut with a pelletizer to obtain a pellet-shaped cleaning composition.

<Performance evaluation of cleaning composition>
The ABS red-colored product was filled into the injection molding machine and then discharged by an injection operation to empty the molding machine.
Next, the cleaning composition shown in Table 1 was put into an injection molding machine to perform an injection operation (cleaning injection operation), and the weight of the cleaning composition required until the influence of the ABS red product disappeared (in Table 1). The amount used (a)) was measured.
Finally, in order to replace the cleaning agent composition, an injection operation (substitution injection operation) is performed with a general-purpose polystyrene (GPPS) transparent molding material, and there is no influence of the residue (foreign matter that impairs transparency). The amount of the GPPS transparent molding material used up to the confirmation (usage amount (b) in Table 1) was measured.
The results are shown in Table 1.

[Example 6, Comparative Example 4]
<Manufacture of cleaning composition>
Polypropylene resin (PP) <Sun Allomer, MFR 15 g / 10 min>, Styrene-Acrylonitrile Resin (AS) <Stylac, MFR 2 g / 10 min>, Acrylic Resin Modified Polytetrafluoroethylene <Metbrene A, manufactured by Mitsubishi Rayon Co., Ltd. -3000 ">, mineral oil (MO) <Idemitsu Kosan Co., Ltd. Diana Process Oil PW-90> in the proportions shown in Table 1, and then melt-kneaded using an extruder to cool the strands After cooling, the pellets were cut with a pelletizer to obtain a pellet-shaped cleaning composition.

<Performance evaluation of cleaning composition>
After the PP red-colored product was filled into the injection molding machine, it was discharged by an injection operation to empty the molding machine.
Next, the cleaning composition shown in Table 1 was put into an injection molding machine to perform an injection operation (cleaning injection operation), and the weight of the cleaning composition required until the influence of the PP red product disappeared (in Table 1). The amount used (a)) was measured.
Finally, in order to replace the cleaning composition, an injection operation (substitution injection operation) is performed with a PP transparent molding material, and it is confirmed that there is no influence of the residue (foreign matter that impairs transparency). The amount of the PP transparent molding material used (the amount used (b) in Table 1) was measured.
The results are shown in Table 1.

[Example 7, Comparative Example 5]
<Manufacture of cleaning composition>
Methacrylic acid resin (PMMA) <Delpet, MFR 2 g / 10 min>, Polypropylene resin (PP) <Sun Allomer, MFR 7 g / 10 min>, Acrylic resin-modified polytetrafluoroethylene <Metbrene A-manufactured by Mitsubishi Rayon Co., Ltd. 3000 ">, mineral oil (MO) <Idemitsu Kosan Co., Ltd. Diana Process Oil PW-90> are mixed in the proportions shown in Table 1, then melt kneaded using an extruder, and the strand is cooled with cooling water. After cooling, it was cut with a pelletizer to obtain a pellet-shaped cleaning composition.

<Performance evaluation of cleaning composition>
The PMMA red-colored product was filled into the injection molding machine and then discharged by an injection operation to empty the molding machine.
Next, the cleaning composition shown in Table 1 was put into an injection molding machine to perform an injection operation (cleaning injection operation), and the weight of the cleaning composition required until the influence of the PMMA red product was eliminated (Table 1). The amount used (a)) was measured.
Finally, in order to replace the cleaning composition, an injection operation (substitution injection operation) is performed with the PMMA transparent molding material until it is confirmed that there is no influence of the residue (foreign matter that impairs transparency). The amount of the PMMA transparent molding material used in the above (amount used (b) in Table 1) was measured.
The results are shown in Table 1.

[Example 8, Comparative Example 6]
<Manufacture of cleaning composition>
Polycarbonate resin (PC) <Lexane>, Polypropylene resin (PP) <Sun Allomer, MFR 7 g / 10 min>, Acrylic Resin-modified Polytetrafluoroethylene <Mitsubrene A-3000 “Metblene A-3000”>, mineral oil ( MO) <Idemitsu Kosan Co., Ltd. Diana Process Oil PW-90>, Wollastonite <"Wollastonite KSP-G01" manufactured by Kansai Matec Co., Ltd.> were mixed in the proportions shown in Table 1, and then extruded. After melt-kneading using a machine and cooling the strand with cooling water, the strand was cut with a pelletizer to obtain a pellet-shaped cleaning composition.

<Performance evaluation of cleaning composition>
After the PC black colored product was filled into the injection molding machine, it was discharged by an injection operation to empty the molding machine.
Next, the cleaning composition shown in Table 1 was put into an injection molding machine to perform an injection operation (cleaning injection operation), and the weight of the cleaning composition required until the influence of the PC black product disappeared (Table 1). The amount used (a)) was measured.
Finally, in order to replace the cleaning composition, an injection operation (substitution injection operation) is performed with a PC transparent molding material until it is confirmed that there is no influence of the residue (foreign matter that impairs transparency, etc.). The amount of the PC transparent molding material used in the above (amount used (b) in Table 1) was measured.
The results are shown in Table 1.

  The cleaning composition of the present invention efficiently cleans additives remaining in the molding machine that are contained in molding materials such as the resin itself and dyes and pigments at the end of predetermined operations in an extrusion molding machine and an injection molding machine. Since it can be discharged, it can be suitably used as a cleaning composition for cleaning the inside of a molding machine for thermoplastic resins.

Claims (6)

It is at least one resin selected from the group consisting of styrene-based resins, polyolefin-based resins, methacrylic acid-based resins and polycarbonate-based resins, and has a melt flow rate of 0.5 to 30 g / 10 minutes (220 ° C. · 10 kg). 100 parts by weight of one thermoplastic resin (A) and at least one resin selected from the group consisting of polyolefin resins and styrene resins that are incompatible with the thermoplastic resin (A), and have a melt flow rate of Containing an incompatible resin mixture containing 0.5 to 10 parts by weight of the second thermoplastic resin (B) at 0.5 to 30 g / 10 minutes (220 ° C. and 10 kg), and a fluorinated polymer. A cleaning composition for a molding machine.   The cleaning composition for a molding machine according to claim 1, comprising 0.5 to 20 parts by weight of a fluorinated polymer with respect to 100 parts by weight of the incompatible resin mixture.   The one of the first thermoplastic resin (A) and the second thermoplastic resin (B) is a polyolefin resin, and the other is a styrene resin. Cleaning composition. The cleaning composition for a molding machine according to any one of claims 1 to 3, wherein the fluorinated polymer is an acrylic resin deformed polytetrafluoroethylene. The cleaning composition for a molding machine according to any one of claims 1 to 4 , comprising at least one selected from the group consisting of an inorganic filler, an acid or acid anhydride-modified polymer, and mineral oil. . It contains 0.1-10 mass% of water, The cleaning composition for molding machines in any one of Claims 1-5 characterized by the above-mentioned.