JPH0214247A - Resin composition for purging plastic molding machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a resin composition for purging a plastic molding machine, and more specifically, it relates to a resin composition for purging a plastic molding machine. A plastic molding machine purge that can be used effectively when purging thermoplastic adhesive resins such as various copolymers, polyamides, and polyesters, not only at temperatures below 250℃ but also at resin temperatures above 250℃. The present invention relates to a resin composition for use.

[Prior Art] Conventionally, resin compositions for purging inside plastic molding machines include polyethylene, inorganic fillers such as white carbon, talc, and clay, sodium lauryl sulfonate, alkylamine hydrochloride, polyoxyethylene sorbitan monostearate, etc. surfactant added (Tokuko Kokko 1977)
-14923), a crosslinked polyethylene resin with a gel fraction of 35 to 90% (Japanese Patent Publication No. 61-4413), a thermoplastic resin with an inorganic filler and paraffin, wax, higher fatty acids or their amides, esters, etc. A lubricant selected from higher alcohols, polyglycols, polyglycerols, higher fatty acid metal soaps, etc.
No. 54647) etc. have been proposed.

[Problems to be Solved by the Invention] However, these purging resin compositions are usually effective at temperatures lower than 250°C, but when the resin temperature in the system is high, such as in extrusion coating, wire coating extrusion, pipe extrusion, etc. 25
If the temperature exceeds 0°C, the additives in the purge resin composition used during purge cleaning will decompose, resulting in smoke, foaming, and adverse effects on the working environment, such as bad odors. If a conventional purge resin composition is used in an extrusion molding machine, it will cause burns on the screw, adapter, or die, which will have a large negative impact on the next product, such as molding defects.

Therefore, when performing purge cleaning using a conventional plastic molding machine purge resin composition, the screws, adapters, or dies used at 250°C or higher should be heated to a temperature higher than 250°C, where the purge resin composition does not undergo thermal decomposition. The temperature must be lowered to a low temperature and purge cleaning must be performed, resulting in time loss in the production process and the need for complicated measures such as readjustment after purge cleaning.

In addition, in the case of a purge resin composition mixed with cross-linked polyethylene, since the cross-linked polyethylene is a super macromolecule, it may clog the extruder screen or be mixed into the product, causing negative effects, especially when extruded coating Difficult to use for wire coatings.

[Means for Solving the Problems] In order to eliminate these drawbacks, the inventors of the present invention made extensive studies and found that by combining a special silicone oil,
We have now invented a purge resin composition that has a high cleaning effect in the system even at a resin temperature of 350°C, and prevents foaming, smoking, odor, and resin deterioration as much as possible.

That is, the object of the present invention has been achieved by a thermoplastic composition for purging a plastic molding machine, which is characterized by containing an organopolysiloxane in a thermoplastic resin.

The present invention will be explained in detail below.

The organopolysiloxane used in the present invention has the general formula (R)s-Si-(0-Si-), -0-3i-(R)
s (where R is a monovalent hydrocarbon group, and a represents the viscosity of the organopolysiloxane at 10 cps, 25°C to 100.
0OOcps, a positive integer that normalizes the viscosity within the range of 25°C) is used. Normally, the value of a that normalizes the viscosity of organopolysiloxane to 10 cps is about 10, which normalizes the viscosity to 100,000 cps. The value of a is about 200
It is 0.

The hydrocarbon group R in the above general formula includes alkoxy,
These include aryl and aralkyl. Examples of alkyl include methyl, ethyl, propyl, butyl, octyl, decyl and the like. Examples of aryl include phenyl and naphthyl. Examples of aralkyl include benzyl and phenylethyl, and mixtures of any of these may also be used.

Organopolysiloxanes used as slip agents include higher alkylpolysiloxanes, alkylphenylpolysiloxanes, alkylphenylpolysiloxanes, diphenylpolysiloxanes, etc., which have good compatibility with polyethylene, good crosstalk properties, and excellent heat resistance.

Furthermore, the organopolysiwaxane that effectively acts on the problems to be solved by the present invention has a viscosity of 1Ocps.
(25℃) to 100,000 cps (25℃),
If the viscosity is lower than 10 cps (25°C), the kneading into the thermoplastic resin will be uneven, resulting in
If the temperature is higher than 25°C, it will take time to switch from purge cleaning to remanufacturing in the low temperature barrel section.
Undesirable.

The amount of these organopolysiloxanes added is determined by the thermoplastic (
M fat 100! ! It is effective to use 1 to 30 parts by weight, preferably 1 to 15 parts by weight. If it is less than 1 part by weight, slip properties will be insufficient, and if it is more than 30 parts by weight, cross-wire and extrusion will become difficult.

Furthermore, the resin composition for purging a plastic molding machine in the present invention may contain an inorganic filler, an antioxidant, and others in addition to the organopolysiloxane.

Inorganic compounds such as calcium carbonate, silicon dioxide, titanium dioxide, talc, superfloss, and alumina oxide are used as inorganic fillers, but the average particle size is 10μ to prevent damage to the screw and grip of the extruder due to wear.
The following are desirable, and the amount added can be 5 to 130 parts by weight, preferably 8 to 80 parts by weight, per 100 parts by weight of the thermoplastic resin. If the amount added is more than 130 parts by weight, it becomes difficult to add and disperse into a resin with a small melt index, and the load on the extruder increases. If the amount is less than 5 parts by weight, the effect of physically peeling off the remaining adhesive resin in the system will be reduced.

It is also necessary to select an antioxidant that decomposes slowly at temperatures above 250° C. and has low volatility. Types include p-phenylenediamines such as N,N'-di-2-naphthyl-p-phenylenediamine, N-cyclohexyl-No-phenyl-p-phenylenediamine, 2,2
．． Quinolines such as 4-trimethyl-1,2-dihydroquinone, 6-nitoxy 2.2.4-1 lythyl-1.2 dihydroquinoline, 2,6-di-t-butyl-4-methylphenol, n-tadecyl Monophenols such as -3-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate, 2,2'-methylene-bis-(4-methyl-6-t-butylphenol), 2.2
°-thiodiethylenebis-(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), 1
．． 3,5-trimethyl-2,4,6-tris(3,5-
di-t-butyl-4-hydroxybenzyl)benzene,
Tetrakis-[methylene-3-(3',5'-di-
Bis, tris polyphenols such as t-butyl-4°-hydroxyphenyl)propionate comethane, 4,4
Thiobisphenols such as °-thiobis-(6-t-butyl-3-methylphenol, 4°4°-thiobis(6-t-butyl-0-cresol), tetrakis(2,4
-di-t-butylphenyl) 4.4' Organophosphoric acids of biphenylene diphosphonite, organic phosphite esters such as distearylpentaerycilitol-diphosphite, 1.3.5-tris(4- A thermoplastic resin containing antioxidants selected from isocyanuric acids such as t-butyl-3-hydroxy-2゜6-dimethylbenzyl)incyanuric acid alone or in combination of two or more
It is effective and desirable to add 0.001 to 6 parts by weight.If it is less than 0.001 part by weight, no effect will be seen by the addition of antioxidant.If it is more than 6 parts by weight, it is particularly problematic. However, the effect proportional to the amount added cannot be obtained, and the economical maximum ffi is preferably 6 parts by weight or less.

Other additives include antistatic agents, ultraviolet absorbers, and heat-resistant organic pigments that can be substituted for or used in combination with the inorganic fillers, provided they do not impair the purge cleaning effect.

The thermoplastic resin used in the present invention has a melt index (same as MI) to enhance the purge cleaning effect.
(JIS K-6760) The smaller the value, the more effective it is. Of course, it is better to take into account the viscosity of the resin depending on the motor capacity of the molding machine and the processing temperature at which you want to purge, as well as the melt index of the resin to be used in the next process. Among these, resins having a melt index of 0.3 to 5 are desirable. If the melt index exceeds 5 when used at a temperature of 250° C. or higher, the extrusion discharge pressure becomes small, the tube wall friction force becomes small, and the purging effect becomes poor. Moreover, if the melt index is smaller than 0.3, the motor load becomes large and addition of inorganic filler becomes difficult.

The thermoplastic resin fill used in the present invention may be of any type as long as it melts at 250°C and exhibits fluidity, but it is preferably of the same type as the resin manufactured by the plastic molding machine. Thermoplastic resins are particularly preferred in such cases because they can be switched from purge cleaning to production again in a short time and require only simple machine adjustments. Examples of the thermoplastic resin include polyolefin, polystyrene, AS, ABS, polycarbonate, polyamide, and polyester resin. However, taking into consideration the purge effect of the resin, dispersion of organopolysiloxane and inorganic filler, ease of handling, economic efficiency, mutual compatibility, crosstalk, etc., polyolefin resin is preferable, and polyethylene is the best overall. Used as a preferred resin.

[Function] The thermoplastic resin composition for purging of a plastic molding machine of the present invention contains organopolysiloxane in the thermoplastic resin, so that the thermoplastic resin composition for purging is applied to the inner wall surface heated to a temperature of 250°C or higher due to the slip effect. Sticking is prevented and there is no burning due to retention, and the thermoplastic resin composition for purging is quickly extruded out of the system while cleaning the wall surface. Furthermore, since the organopolysiloxane itself has higher heat resistance than conventionally used lubricants such as fatty acid metal salts, there is less thermal decomposition and smoke and bad odors are suppressed.

[Example] Next, the present invention will be explained by examples.

Table 1 summarizes the purge resin compositions and evaluation results of Examples 1 to 24 and Comparative Examples 1 to 7.

The numbers in the table represent parts by weight of the materials used.

A T-die extruder with 1 plate, 65 mm, and L/D = 28 was set at a resin temperature of 300°C, and resin 25 colored with T i O* was used.
kg was shed. After that, L produced using a Banbury kneader
100 parts by weight of DPE (MI=1), 5 parts by weight of methylphenylpolysiloxane (400 cps, 25°C) and the antioxidant n-octadecyl-3-(4°-hydroxy-3).
°, 5°-di-t-butylphenyl) propionate [
A compound containing 0.5 parts by weight of AO-1] and 15 parts by weight of an inorganic filler was made into a uniform pellet form, and heated at 100 r.
The extrusion was carried out at screw rotation speeds of p and m, and the foamability, smoke-emitting property, heat resistance, odor, and purge effect were evaluated by visual inspection and other sensory tests.

In Example 1, cross-talk due to Banbury was easy, and great improvements were seen in preventing smoke, odor, and foaming.

1st grade Methylphenylpolysiloxane (400cps, 25℃
) was reduced from 5 parts by weight to 3 parts by weight -
A compound was prepared and evaluated in the same manner as in Example 1. Similar to Example-1, significant improvements were seen in foaming, smoking, odor, and purging effect.

A large amount of LfL2L antioxidant is tetrakis-methylene-3-(3°, 5
[-di-t-butyl-4°-hydroxyphenyl)propione-i'] [AO-2] was used, and evaluation was performed in the same manner as in Example-2. Similar to Examples 1 and 2, this also showed a significant improvement in the prevention of foaming, smoke, and odor.

K Plate Plate 2A Antioxidant is added to tetrakis-[methylene-3-(3°
5°-di-t-butyl-4′-hydroxyphenyl)propionate] [AO-2] and tetrakis(2,4
Example-2
The evaluation was carried out in the same way. The heat resistance was further improved compared to Example 2, and a significant improvement was seen in the purging effect and the prevention of smoke and odor.

Example-4 using LDPE with fire LL-mutual melt index = 3
The same antioxidant was increased from 0.5 parts by weight to 0.8 parts by weight, and evaluation was performed in the same manner as in Example 2. Significant improvements were seen in zero foaming, smoke generation, odor, and heat resistance. , LDPE with a melt index of 1 has a slightly greater purging effect.

LDPE with a melt index of 8 was used, an antioxidant, l, 3.5-1-methyl-2,4,6-tris (3
, 5-di-t-butyl-4-hydroxybenzyl)benzene [AO-4] was added, and evaluation was performed in the same manner as in Example-2. Melt index = 3 L in Example-5
DPE has a greater purge effect.

However, other improvements such as foaming, smoke, and odor were greatly improved.

The viscosity (degree of polymerization) of the methylphenyl polysiloxane is 30.
Evaluation was conducted using the same composition as in Example 4 instead of 5000 cps and 5000 cps, and as in Example 4, the foaming, smoking, odor, heat resistance, and purging effect were greatly improved.

1ON13 Instead of methylphenylpolysiloxane, use methylphenethylpolysiloxane (400cps, 100cps,
The evaluation was conducted using dimethylpolysiloxane (100cps) and Example 4.
Similarly, foaming, smoking, odor, heat resistance, and purging effects were greatly improved.

2. When O is added as organopolysiloxane and oleic acid amide is added as a slip agent, there is a lot of smoke and foaming, and there is no function as a purge resin at high temperatures.

If methylphenylpolysiloxane and an antioxidant are not added to the composition of Example 1, the resin will deteriorate and the purge effect will deteriorate.

In place of organopolysiloxane, slip agents such as oleic acid amide, erucic acid amide and polyethylene wax,
Also, addition of glycerol monostearate, etc. caused decomposition and fuming, and no improvement was observed.

Among the compositions of Comparative Example-3, L without adding an inorganic filler
The compound consisting of DPE, oleic acid amide, and antioxidant had almost no purging effect for cleaning the seizure on the pipe wall surface.

Maru Kansho Jo Yuyu 1 Instead of dimethylpolysiloxane having a viscosity of 100 cps in Example-13, Example-14 had a viscosity of 10 cps.

In Example 15, evaluation was performed using 100,000 cps of dimethylpolysiloxane, and it was demonstrated that the effects of the present invention were effective.

-16 to 18 Usage amount 3 of methylphenylpolysiloxane in Example-4
Instead of parts by weight, in Example-16, 1 part by weight, Example-
The evaluation was carried out using 20 parts by weight for Example 17 and 30 parts by weight for Example 18, and it was demonstrated that the effects of the present invention were effective.

- Application 1-19 to 22 In place of the amount of inorganic filler used in Example-4, 15 parts by weight,
5 parts by weight in Example-19, 50 parts by weight in Example 20, 100 parts by weight in Example-21, and 1 part by weight in Example-22.
The evaluation was conducted using 30 parts by weight of each, and it was verified that the effects of the present invention were effective.

-23 to 24 Instead of 0.5 parts by weight of the antioxidant [AO-1] in Example-2, 0.001 parts by weight was used in Example 23, and 6 parts by weight was used in Example-24. The evaluation demonstrated that the effects of the present invention are widespread.

[Effect of the invention] As seen in the examples, the thermoplastic resin composition for purging a plastic molding machine containing an organopolysiloxane was heated to 250°C during purge cleaning of a plastic molding machine.
Even at these high resin temperatures, workability such as smoking, foaming, and bad odors was improved, and excellent purging effects were achieved.

Claims (7)

[Claims] (1) A thermoplastic resin composition for purging a plastic molding machine, characterized by containing an organopolysiloxane in the thermoplastic resin. (2) The general formula for organopolysiloxane is ▲ There are mathematical formulas, chemical formulas, tables, etc.
The thermoplastic resin composition for purging a plastic molding machine according to claim 1, which has a positive integer such that the temperature is within the range of 00 cps and 25°C. (3) The thermoplastic resin composition for purging a plastic molding machine according to claim (1), which contains 1 to 30 parts by weight of organopolysiloxane per 100 parts by weight of the thermoplastic resin. (4) The thermoplastic resin composition for purging a plastic molding machine according to claim (3), further containing 5 to 130 parts by weight of an inorganic filler based on 100 parts by weight of the thermoplastic resin. (5) The thermoplastic resin composition for purging a plastic molding machine according to claim (3) or (4), further containing 0.001 to 6 parts by weight of an antioxidant based on 100 parts by weight of the thermoplastic resin. (6) The thermoplastic resin composition for purging a plastic molding machine according to claim (1), wherein the thermoplastic resin is the same type of thermoplastic resin as the plastic to be purged. (7) Claim (1) in which the thermoplastic resin is polyethylene.
Alternatively, the thermoplastic resin composition for purging a plastic molding machine according to (6).