JP7112797B2 - Cleaning agents for molding machines - Google Patents

Description

The present invention relates to a cleaning agent for molding machines.

Injection molding machines and extrusion molding machines are mainly used for molding thermoplastic resins. After use of these molding machines, the resin, additives such as pigments added to the resin, and degraded resin generated during molding remain in the molding machine. If the next resin molding process is carried out while these residues are present, the residues will be mixed into the molded product, deteriorating the appearance of the molded product and degrading the expected physical properties of the resin. end up

In order to reduce the influence of such preceding resin, the interior of the molding machine may be washed by the resin used in the subsequent molding process. However, this method requires a large amount of resin to wash the molding machine, which is costly, and has the problem that dirt in the molding machine cannot be completely removed.

Therefore, various cleaning agents for cleaning molding machines have been investigated. For example, Patent Document 1 proposes a cleaning agent for molding machines having a melt mass flow rate of 10 to 35 g/10 minutes.

JP 2018-069473 A

However, with the cleaning agent as described above, since the resin has a relatively low viscosity, the shearing force during cleaning may not be sufficient, and there is a limit to obtaining a higher cleaning effect.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cleaning agent for a molding machine capable of satisfactorily removing residual resin materials such as resins or resin compositions remaining in the molding machine after molding processing.

As a result of intensive studies to solve the above problems, the present inventors found that the problems can be solved by the present invention described below. That is, the present invention is as follows.

[1] Contains a thermoplastic resin and at least one cleaning agent selected from the group consisting of surfactants, inorganic fillers, and paraffins, and has a melt mass flow rate (190°C, load 2.16 kg) of A detergent for a molding machine, which is more than 0.01 g/10 minutes and not more than 1.0 g/10 minutes, and has a content of the detergent compounding agent of not more than 35% by mass.
[2] The molding machine according to [1], which contains the surfactant and has a mass ratio [surfactant/thermoplastic resin] between the surfactant and the thermoplastic resin of 0.02 to 0.1. cleaning agent.
[3] The cleaning agent for a molding machine according to [1] or [2], which contains the surfactant, and the surfactant is a nonionic surfactant.
[4] The cleaning agent for molding machines according to any one of [1] to [3], wherein the thermoplastic resin is ultrahigh molecular weight polyethylene.
[5] The molding machine according to any one of [1] to [4], which contains the paraffin and has a mass ratio [paraffin/(paraffin + polyolefin)] of the paraffin and the thermoplastic resin of 0.4 or less. cleaning agent.
[6] The cleaning agent for a molding machine according to any one of [1] to [5], which contains the inorganic filler and has a content of the inorganic filler of 1 to 35% by mass.
[7] The cleaning agent for molding machines according to any one of [1] to [6], wherein the molding machine is an extrusion molding machine or an injection molding machine.

According to the present invention, it is possible to provide a cleaning agent for a molding machine that can satisfactorily remove residual resin materials such as resins or resin compositions that remain in the molding machine after molding processing.

A molding machine cleaning agent according to one embodiment (this embodiment) of the present invention comprises a thermoplastic resin and at least one cleaning agent selected from the group consisting of a surfactant, an inorganic filler, and paraffin. and a melt mass flow rate (MFR) of more than 0.01 g/10 minutes and 1.0 g/10 minutes or less. If the MFR is less than 0.01 g/10 minutes, it is difficult to melt under normal use conditions (200 to 400° C.) and cannot be used as a cleaning agent. If it exceeds 1.0 g/10 minutes, the cleaning agent may not be sufficiently compatible with the resin material residue, or the effect of scraping off the resin material residue due to stickiness due to high viscosity may be reduced, resulting in a sufficient cleaning effect. I can't get it. MFR is preferably 0.1 to 0.8 g/10 minutes, more preferably 0.1 to 0.5 g/10 minutes.

In order to set the MFR of the cleaning agent for molding machines to 0.01 to 1.0 g/10 minutes, for example, a resin with a low MFR (eg, ultrahigh molecular weight polyethylene) is used as the thermoplastic resin, and paraffin or the like is added to the resin. A desired MFR may be adjusted by blending an inorganic filler.

Here, the MFR of the cleaning agent shall be measured under conditions of 190° C. and a load of 2.16 kg in accordance with ISO1133.
Specifically, a dry cleaning agent is placed in a cylinder (9.5 mmφ in inner diameter) preheated to the measurement temperature (190° C.). After the cleaning agent reaches the measurement temperature (190°C), it is cleaned from the orifice (inner diameter: 2.095 mmφ) attached to the bottom of the cylinder by applying a predetermined load (2.16 kg) to the piston that is inserted into the cylinder. push out the agent. Then, the mass of the detergent extruded in 10 minutes is determined as MFR.

In addition, the content of the cleaning compounding agent in the cleaning agent for molding machines according to the present embodiment is 35% by mass or less. If the content of the cleaning agent exceeds 35% by mass, a sufficient cleaning effect cannot be obtained. The detergent compounding agent is at least one kind selected from the group consisting of surfactants, inorganic fillers and paraffins, but may be two or more kinds. When two or more cleaning agents are used, the content of each of them is preferably 35% by mass or less, and the total content thereof is more preferably 35% by mass or less.

The thermoplastic resin and other components contained in the cleaning agent for molding machines according to this embodiment will be described below.
(Thermoplastic resin)
As the thermoplastic resin, various resins may be used singly or in combination, as long as the MFR of the cleaning agent for molding machines is more than 0.01 g/10 minutes and not more than 1.0 g/10 minutes. Examples include polyethylene, polypropylene, polystyrene, AS resin, ABS resin, polybutene resin, polymethyl methacrylate resin, etc., and polyethylene is preferred.

Polyethylene includes, for example, high-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, linear low-density polyethylene, ultra-high molecular weight polyethylene, polyethylene obtained using a metallocene compound as a polymerization catalyst, cyclic polyethylene, and maleic anhydride-modified polyethylene. , glycidyl (meth)acrylate-modified polyethylene, 2-hydroxyethyl (meth)acrylate-modified polyethylene, and other modified polyethylene resins.

Among them, from the viewpoint of ease of adjustment of MFR and effective cleaning of dirt on screws and cylinders with high-viscosity shear, the main component of the thermoplastic resin is ultra-high molecular weight polyethylene (preferably 50% by mass or more, more than 80% % by mass or more).
The term ultra-high molecular weight polyethylene as used herein refers to polyethylene having a weight average molecular weight of 1 million or more (preferably 2 million to 12 million, more preferably 4 million to 10 million). , an α-olefin having 3 to 20 carbon atoms, a cyclic olefin having 3 to 20 carbon atoms, a compound represented by the formula CH ₂ ═CHR ¹ (R ¹ is an aryl group having 6 to 20 carbon atoms), and Also included are those copolymerized with at least one olefin selected from the group consisting of 4 to 20 linear, branched or cyclic dienes.

(Surfactant)
It is preferable that the cleaning agent for a molding machine according to the present embodiment further contains a surfactant from the viewpoint of penetration into resin material residue and improvement of cleaning properties.
Surfactants are not particularly limited, and include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. One or more of these surfactants can be used.

Examples of anionic surfactants include phosphate surfactants, sulfonate surfactants, sulfate surfactants, and fatty acid surfactants.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene phenyl ethers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyglycerin fatty acid esters, polyoxyethylene fatty acid esters, and the like.

Cationic surfactants include primary amine hydrochlorides, secondary amine hydrochlorides, tertiary amine hydrochlorides, ethanolamine hydrochlorides, polyethylenepolyamine hydrochlorides, amine hydrochlorides, and the like. mentioned.

Examples of amphoteric surfactants include alkyldimethylamine oxides and alkylcarboxybetaines.

Among the above, anionic surfactants and nonionic surfactants are preferred, nonionic surfactants are more preferred, and poly Glycerol fatty acid esters are more preferred.

The mass ratio of the surfactant to the thermoplastic resin [surfactant/thermoplastic resin] is preferably 0.02 to 0.1, more preferably 0.03 to 0.08. When it is 0.02 to 0.1, it is possible to maintain viscosity and effect effective in detergency.

In addition, the content of the surfactant in the cleaning agent for molding machines (the total amount when multiple types are used) should be 1 to 35% by mass from the viewpoint of more effectively exhibiting the effect of the surfactant. is preferred, more preferably 1 to 25% by mass, even more preferably 1 to 15% by mass.

(Inorganic filler)
It is preferable that the cleaning agent according to the present embodiment further contains an inorganic filler from the viewpoint of improving the cleaning property by the polishing effect and adjusting the viscosity. Inorganic fillers include calcium carbonate, calcium sulfate, calcium sulfite, magnesium carbonate, calcium silicate, barium sulfate, talc, mica, clay, monmonlilonite, smectite, kaolin, glass fiber, glass milled fiber, glass flake, and carbon fiber. , carbon flakes, carbon beads, carbon milled fibers, silica, ceramic particles, ceramic fibers, and ceramic balloons. Among them, kaolin, calcium carbonate and talc are preferred, and talc is more preferred.

The volume-average particle size of the inorganic filler is not particularly limited, and is preferably 0.1 to 50 μm, more preferably 1 to 30 μm, from the viewpoint of cleaning effect of resin material residue, ease of blending into thermoplastics, and the like. It is more preferable to have The volume average particle diameter can be measured by a laser diffraction scattering method.

The mass ratio [inorganic filler/thermoplastic resin] between the inorganic filler and the thermoplastic resin is preferably 0.6 or less, more preferably 0.3 or less. When it is 0.6 or less, it is possible to maintain viscosity and effect effective in detergency.

In addition, the content of the inorganic filler in the cleaning agent for molding machines (the total amount when multiple types are used) is preferably 1 to 35% by mass from the viewpoint of more effectively exhibiting the effect of the inorganic filler. , more preferably 1 to 25% by mass, more preferably 1 to 15% by mass.

(paraffin)
The cleaning agent according to the present embodiment preferably further contains paraffin from the viewpoint of plasticization and releasability. Liquid paraffin is preferred as the paraffin.
Liquid paraffin preferably has a kinematic viscosity at 40° C. of 1 to 200 mm ² /s, more preferably 5 to 100 mm ² /s, as measured by the method specified in JIS K2283. When the 40° C. kinematic viscosity is within the above range, handling becomes easy and liquid paraffin dispersibility in the resin becomes good.

The mass ratio [paraffin/thermoplastic resin] between paraffin and thermoplastic resin is preferably 0.4 or less, more preferably 0.3 or less. By being 0.4 or less, it is possible to maintain viscosity and effect effective in detergency.
When paraffin is contained, the lower limit of [paraffin/thermoplastic resin] is preferably about 0.01.

In addition, the content of paraffin in the cleaning agent for molding machines (the total amount when multiple types are used) is preferably 1 to 35% by mass from the viewpoint of more effectively exhibiting the effect of the paraffin. It is more preferably from 10 to 30% by mass, and even more preferably from 10 to 27% by mass.

(Optional component)
The resin composition of the present invention may optionally contain optional components. Examples thereof include heat stabilizers, metallic soaps, antifoaming agents, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, lubricants, release agents, antistatic agents, and flame retardants.

Examples of heat stabilizers added to improve heat stability during production include phosphorus antioxidants, hindered phenol antioxidants, phosphite antioxidants, lactone antioxidants, and the like. be done. From the viewpoint of effectively obtaining the effect of improving thermal stability, the mass ratio of the thermal stabilizer and the thermoplastic resin [thermal stabilizer/thermoplastic resin] is preferably 1 or less, and 0.01 to 1. preferably 0.01 to 0.6.

Examples of metal soaps include metal salts of linear aliphatic monocarboxylic acids having 12 to 18 carbon atoms. Examples of linear aliphatic monocarboxylic acids having 12 to 18 carbon atoms include lauric acid, palmitic acid, stearic acid, oleic acid, ricinoleic acid and the like. Metal salts include calcium salts, zinc salts, magnesium salts, barium salts, aluminum salts and the like.

The cleaning agent according to the present embodiment is obtained by mixing each material with, for example, a tumbler mixer or a high-speed mixer and kneading (melting and kneading) with an extruder. The shape thereof may be powder, granule, pellet, flake, or a mixture thereof.

Here, melt-kneading can be performed using, for example, a Banbury mixer, two-roll, three-roll, single-screw kneading extruder, and twin-screw kneading extruder. Melt-kneading may be performed in one step or in multiple steps. The melt-kneading temperature is not particularly limited as long as the thermoplastic resin is sufficiently melted and thermal deterioration of the thermoplastic resin is not a problem. For example, the melt-kneading temperature is preferably about 150 to 250°C.

The melt-kneaded product can be formed into powder, granules, pellets, and flakes by a known method, as required.

(Washing method)
In the method of cleaning a molding machine using the cleaning agent for molding machines according to the present embodiment, the cleaning agent is put into the cylinder of the resin molding machine, the cleaning agent is heated to be plasticized (melted) and held, and then This is a method of discharging the plasticized cleaning agent from the inside of the cylinder of the resin molding machine.

Applicable resin molding machines include, for example, injection molding machines and extrusion molding machines, but are particularly limited to these as long as they have a cylinder for heat-melting and kneading (mixing) the resin. is not. That is, the cleaning agent of the present invention can be widely applied to known resin molding machines.
The cylinder temperature of the resin molding machine when heating the cleaning agent is preferably 180° C. or higher, more preferably 200° C. or higher. Although the upper limit of the heating temperature is not particularly limited, it is usually about 400°C.

The cleaning agent for molding machines of the present invention effectively removes residual resin materials contained in molding materials such as the resin itself and dyes and pigments and remaining in the molding machine at the end of predetermined operations in the extrusion molding machine and the injection molding machine. Since it can be washed and discharged well, it can be suitably used as a cleaning agent composition for cleaning the inside of a thermoplastic resin molding machine, and the molding machine is an extrusion molding machine or an injection molding machine. preferable. That is, the cleaning agent for molding machines of the present invention is preferably a cleaning agent for extruders or injection molding machines. In particular, it is preferable to be a cleaning agent for extruders.

In particular, the preceding resins are PA (polyamide), PMMA (polymethyl methacrylate (acrylic)), PLA (polylactic acid), ABS (acrylonitrile-butadiene-styrene copolymer), AS (acrylonitrile-styrene copolymer resin), PVC ( Polyvinyl chloride), PVDF (polyvinylidene fluoride (polyvinylidene fluoride)), TPU (polyurethane), PC (polycarbonate), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), POM (polyacetal) and other highly polar resins, and a resin composition containing the resin as a main component (50% by mass or more, preferably 70% by mass or more).
A highly polar resin is a resin having a polar group such as a carboxyl group, an amino group, an ester group, a sulfone group, a cyano group, a thiol group, a hydroxyl group, and an amide group.

EXAMPLES Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these.

[Example 1]
7.8 parts by mass of ultra-high molecular weight polyethylene pellets (weight average molecular weight of 1,000,000 or more) having an MFR of 0.16 g/10 min, 2 parts by mass of talc powder having a volume average particle size of 25 μm (manufactured by Hayashi Kasei Co., Ltd.), poly After mixing 0.2 parts by mass of glycerin fatty acid ester (SY Glister TS-3S, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) in a tumbler, using a twin-screw kneading extruder (JSW TEX30α, manufactured by Japan Steel Works, Ltd.), The mixture was melt-kneaded at 200° C. and molded into pellets (diameter: 3 mm, height: 3 mm) to prepare a cleaning agent for molding machines.
The prepared cleaning agent for molding machine was measured for MFR by MELT FLOW INDEX TESTER (model SAS2000) manufactured by Yasuda Seiki Seisakusho. The results are shown in Table 1 below (MFR was measured in the same manner for Examples and Comparative Examples below).

[Example 2]
7.8 parts by mass of ultra-high molecular weight polyethylene pellets (weight average molecular weight of 1,000,000 or more) having an MFR of 0.16 g/10 min, liquid paraffin (carnation, manufactured by Witco, density 0.857 g/cm ³ , pour point −12 .5 ° C., average molecular weight 365) 1.5 parts by mass, polyglycerin fatty acid ester (SY Glister TS-3S, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) 0.7 parts by mass were mixed in a tumbler, and then a twin-screw kneading extruder ( JSW TEX30α (manufactured by Japan Steel Works, Ltd.) was melt-kneaded at 200° C. and molded into pellets (diameter: 3 mm, height: 3 mm) to prepare a detergent for molding machines.

[Example 3]
7.0 parts by mass of ultra-high molecular weight polyethylene pellets (weight average molecular weight of 1,000,000 or more) having an MFR of 0.16 g/10 min, liquid paraffin (carnation, manufactured by Witco, density 0.857 g/cm ³ , pour point −12 .5 ° C., average molecular weight 365) 2.5 parts by mass, polyglycerin fatty acid ester (SY Glister TS-3S, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) 0.5 parts by mass were mixed in a tumbler, and then a twin-screw kneading extruder ( JSW TEX30α (manufactured by Japan Steel Works, Ltd.) was melt-kneaded at 200° C. and molded into pellets (diameter: 3 mm, height: 3 mm) to prepare a detergent for molding machines.

[Example 4]
9.8 parts by mass of ultra-high molecular weight polyethylene pellets having an MFR of 0.16 g/10 min (weight average molecular weight of 1,000,000 or more), polyglycerin fatty acid ester (SY Glister TS-3S, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) After mixing 2 parts by mass in a tumbler, melt-knead at 200 ° C. using a twin-screw kneading extruder (JSW TEX30α, manufactured by Japan Steel Works, Ltd.) to form pellets (diameter: 3 mm, height: 3 mm). It was molded to prepare a cleaning agent for a molding machine.

[Example 5]
9.9 parts by mass of ultra-high molecular weight polyethylene pellets with an MFR of 0.16 g/10 min (weight average molecular weight of 1,000,000 or more), polyglycerin fatty acid ester (SY Glister TS-3S, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) After mixing 1 part by mass with a tumbler, melt-knead at 200 ° C. using a twin-screw kneading extruder (JSW TEX30α, manufactured by Japan Steel Works, Ltd.) to form pellets (diameter: 3 mm, height: 3 mm). It was molded to prepare a cleaning agent for a molding machine.

[Example 6]
9.3 parts by mass of ultra-high molecular weight polyethylene pellets (weight average molecular weight of 1,000,000 or more) having an MFR of 0.16 g/10 min, polyglycerin fatty acid ester (SY Glister TS-3S, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) After mixing 7 parts by mass with a tumbler, using a twin-screw kneading extruder (JSW TEX30α, manufactured by The Japan Steel Works, Ltd.), it is melted and kneaded at 200 ° C. to form pellets (diameter: 3 mm, height: 3 mm). It was molded to prepare a cleaning agent for a molding machine.

[Example 7]
9.0 parts by mass of ultra-high molecular weight polyethylene pellets (weight average molecular weight of 1,000,000 or more) having an MFR of 0.16 g/10 min, polyglycerin fatty acid ester (SY Glister TS-3S, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.)1. After mixing 0 parts by mass with a tumbler, melt-knead at 200 ° C. using a twin-screw kneading extruder (JSW TEX30α, manufactured by Japan Steel Works, Ltd.) to form pellets (diameter: 3 mm, height: 3 mm). It was molded to prepare a cleaning agent for a molding machine.

[Comparative Example 1]
5.0 parts by mass of ultra-high molecular weight polyethylene pellets with an MFR of 0.16 g/10 min (weight average molecular weight of 1,000,000 or more), 5.0 parts by mass of talc powder with a volume average particle size of 25 μm (manufactured by Hayashi Kasei Co., Ltd.) After mixing with a tumbler, melt-knead at 200 ° C. using a twin-screw kneading extruder (JSW TEX30α, manufactured by Japan Steel Works, Ltd.) to form pellets (diameter: 3 mm, height: 3 mm), A cleaning agent for molding machines was prepared.

[Comparative Example 2]
5.0 parts by mass of ultra-high molecular weight polyethylene pellets (weight average molecular weight of 1,000,000 or more) having an MFR of 0.16 g/10 min, liquid paraffin (carnation, manufactured by Witco, density 0.857 g/cm ³ , pour point −12 After mixing 5.0 parts by mass of .5 ° C., average molecular weight 365) in a tumbler, using a twin-screw kneading extruder (JSW TEX30α, manufactured by Japan Steel Works, Ltd.), it is melted and kneaded at 200 ° C. to form pellets ( (Diameter: 3 mm, Height: 3 mm) to prepare a cleaning agent for a molding machine.

<Washing evaluation>
The temperature of the twin-screw kneading extruder (JSW TEX30α, manufactured by The Japan Steel Works, Ltd.) was raised to 250°C. After the temperature was raised, 500 g of nylon 6 (Amilan CM1017, manufactured by Toray Industries, Inc.) with a carbon black masterbatch of 1% by mass was added to a kneader. After the completion of charging, the rotation of the screws of the twin-screw kneading extruder was stopped and the mixture was retained for 30 minutes to contaminate the inside of the kneader. After 30 minutes, the screw was restarted and 2 kg of each cleaning agent was introduced. After the cleaning agent is discharged, the screw is pulled out, (1) the amount of 6 nylon remaining on the screw is visually judged from the surface area, and the cleaning power is judged according to the following criteria. The easiness of removing substances (easiness of removing residual substances) was judged according to the following criteria. The results are shown in Table 1 below.

-(1) Detergency criteria-
A: No residue of 6 nylon (residual amount 0 to 2% by area)
B: Almost no residue of 6 nylon (residual amount 3-5% by area)
C: There is a slight residue of 6 nylon (residual amount 6 to 10 area%)
D: A large amount of residual 6 nylon (residual amount of 11 area% or more)

-(2) Criteria for ease of removal of residue-
A: Can be easily removed with a brush B: Can be removed with a brush, but requires considerably more force than A and/or requires more work time than A C: Cannot be removed sufficiently with a brush, leaving residue there is a place to

[Examples 9 to 14, Comparative Examples 3 and 4]
Ultra-high molecular weight polyethylene pellets with an MFR of 0.31 g / 10 min (weight average molecular weight of 1 million or more) and various inorganic fillers are mixed in a tumbler so that the ratio shown in Table 2 below is obtained. Using TEX30α (manufactured by Japan Steel Works, Ltd.), the mixture was melt-kneaded at 200° C. and molded into pellets (diameter: 3 mm, height: 3 mm) to prepare a cleaning agent for a molding machine. Detergency was evaluated in the same manner as in Example 1. Table 2 shows the results.
In addition, the detail of an inorganic filler is shown below.
・ Talc powder (manufactured by Hayashi Kasei Co., Ltd., volume average particle size 25 μm)
・ Calcium carbonate powder (manufactured by Sankyo Seifun Co., Ltd., volume average particle size 5 μm)
・ Kaolin powder (manufactured by IMERYS, volume average particle size 1 μm)

Claims (2)

containing a thermoplastic resin and at least one detergent compounding agent selected from the group consisting of surfactants, inorganic fillers (excluding boric acid), and paraffins;
Melt mass flow rate (190 ° C., load 2.16 kg) is more than 0.01 g / 10 minutes and 0.8 g / 10 minutes or less ,
The content of the cleaning compounding agent is 35% by mass or less,
A cleaning agent for a molding machine containing 1 to 15% by mass of the inorganic filler. The inorganic filler is calcium carbonate, calcium sulfate, calcium sulfite, magnesium carbonate, calcium silicate, barium sulfate, talc, mica, clay, montmontlilonite, smectite, kaolin, glass fiber, glass milled fiber, glass flake, carbon fiber. , carbon flakes, carbon beads, carbon milled fibers, silica, ceramic particles, ceramic fibers, and ceramic balloons.