JPS5823804A - Polymer processability improvement and polymer composition - 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 This invention relates to a method for obtaining an I-rib sobilene 4-rimer eyelet, and also to the above-mentioned improved processability. It is preferred that the polypropylene 4-limer has one of the attributes of a manure, that it does not break during attenuation from softening.

Polymers with this property have a high throughput per unit time when processed into fine filaments or thin films with high strength compared to non-attenuated materials.

1) It can be pumped through piping or thin tubes, and/or the amount of energy required to decompose it into fibers or films can be small. This property means that the shear stress and elongational viscosity of the molten polymer are low.

The first attribute of this quantity (high sensitivity) is that the molecular weight distribution (defined as the ratio of weight average molecular weight to number average molecular weight) is small / I
It has been demonstrated that this can be achieved using J delopyrene/17-v-. The first attribute (low shear stress and low elongational viscosity) can be achieved using polymers with low weight average molecular weights.

If fine fibers or thin films are produced using the Ziegler-Natsuta catalyst currently used in the production of commercially available -+7 7" lopyrene, polymers with an excessive molecular weight distribution will come out of the polymerization reactor. Low Weight Average Molecular Weight/Remers produced with low viscosity that are favorable for processing, but are unable to achieve the desired fineness.Therefore, the propylene production industry has sought to reduce the molecular weight distribution while at the same time reducing the weight average molecular weight. There is a need to produce polymers with very high weight average molecular weights after random molecular cleavage (thermal or chemical decay) which has the inherent effect of reducing it to the desired level.

When added to compound 11, it decomposes to form free radicals and is chemically degraded.

- Chemical stabilizers added to increase the end-use stability of lipropylene may interfere with the action of free radical generators.

However, some of the free radical generator type chemicals of the specific class of organic peroxides described in British Patent No. 1 Dadayu No. 6-7, for example, are commonly used cheap! The influence of the agent is minimal and therefore it can be a preferred disintegration promoter.

However, the degree to which the 1mer can be broken down is limited by the fact that the 4S I-maker cannot form a velvet with a very low viscosity. Therefore, K for processing into films and fibers is not optimal for a propylene processing machine that produces films and fibers, and there is an order in which K to be processed into films and fibers must be used as a material. Thus, high viscosity F! There has been a need for polymers with improved properties and low viscosity for end-use processing.

$ +7 Low viscosity preferred by processors? □ Climb the Provirene Rimer! - When manufacturers commercially pelletize, they inevitably produce excessive stringiness (pellets with long tails), which can clog manufacturers' and processors' equipment.

In order to pelletize the polymer, the viscosity is increased to one viscosity. It has been proposed to operate the pelletizer at a temperature slightly above the melting point of Robylene l remer to improve the cutting properties of the pellets. This can only be achieved by lowering the unit production to reduce the heat generated by shear stress in the snow and/or by cooling the molten polymer. However, both of these methods This increases costs and complicates the process.

Also in end-use processing/IJ Mama - Addition of chemical disintegration accelerators before formation into fibers or films? It has also been proposed to add it to rideropyrene pellets to reduce the viscosity of the polymer. However, this method has some disadvantages. /) These peroxide-type disintegration accelerators require special handling processes and equipment due to the risk of ignition and explosion.

c) For peroxide to be effective, it must be uniformly dispersed in the polymer before decomposition and reaction. If this is not done, the viscosity will be uneven/
IJ w- is generated, resulting in a molecular weight distribution that is even wider than that of the polymer before processing. A consumer manufacturer that uses special equipment to produce flakes that are smaller than pellets in a reactor is very helpful in achieving the above-mentioned uniform distribution.
tFF@ is in the correct condition.

3) Processors' equipment may be damaged by 4 remers with uneven viscosity.

D) Before the reaction/If well dispersed in the remer, peroxide functions more efficiently as a disintegration promoter.

S) If peroxide is added simply onto the pellets rather than into the pellets, the peroxide acts as a circulating lubricant in the feed section of the extruder, reducing unit production for a given revolutions per minute. It's heavy and heavy.

The molecular weight can also be reduced by thermally disintegrating I-lipropylene using very high temperatures in the processing step. However, if the temperature is raised to an abnormally high temperature, the following problems will occur.

/) The lifespan of the device is shortened.

2) Since quenching is not possible freely, there is a wlt in unit production.

3) Requires excessive energy consumption ◎Requires high temperatures, making it a dangerous process.

S) Other requests.

The question of the envoy includes the following inclinations.

/) Excessive disintegration requires adding more additive to the polymer than the final product requires.

2) The range of additives that can be used is limited, requiring the use of more expensive or suboptimal additives.

3) When the remer is pumped through piping or thin tubes or applied to wet the die, it becomes clogged with decay products.

Further information is provided by the following prior patents:

British Patent No. 1'14t U6Z7 describes a method for producing polypropylene that includes a step of disintegrating it with a peroxide-type disintegration promoter to produce propylene I remer with a small molecular weight distribution.
I! has been done. U.S. Patent No. 3 A7. ! Issue 11i'#L describes the use of aliphatic peroxides as disintegration accelerators for 4-lipropylene, discusses the problems associated with this, and further discusses the use of unreacted peroxides as a solution to this problem. suggests avoiding disintegration accelerators. U.S. Patent No. 3. / 4t4<936 contains stereoregularity including the use of free radical initiators / IJ Mama-
One method of collapse has been changed. Seven examples describe a two-step process controlling the injection of disintegration promoter into the melt zone of the extruder. U.S. Patent No. 3, Za1Iq24
No. Ii and 'U.S. Pat. No. 3.9'7&/gS describe an improved melt blowing process by controlling the disintegration of the primer. Similarly, U.S. Patent Edition, 7
: ? ,t3. The advantages of polymer disintegration are described in the J-Koku issue.

The present invention consists of stepwise-remer disintegration involving the initial production of a readily formed polymer; and 2) the berette obtained by the method relates to other forms of disintegration accelerator-containing propylene fibers.

The present invention discloses that when a specific free radical generating chemical agent that acts as a disintegration accelerator for propylene is added to the polymer and the pelletizing equipment is operated in the known manner, a portion of the above chemical agent is added to the polymer during the pelletizing process. This is based on the discovery that the reaction remains unreacted even after the

In other words, after the extrusion process to form 4lets, if the reaction is interrupted and extrusion is performed again, the remaining disintegration accelerator reacts to form a film that is easy to process and has transparent properties.
Generates a primer that can be manufactured to The exact residual rate N of the disintegration accelerator after pelletizing in the manufacturing process (depends on the pelletizing temperature, the residence time of the disintegration accelerator at that temperature, and the type of disintegrant. It is preferably from half to 90%.Ideally, it is better that no disintegration occurs during pelletization, but in reality, some of the disintegration accelerator reacts during pelletization. The amount of agent is as small as /θ%, which only slightly lowers the viscosity of the polymer at the time of retardation, so that well-formed, free-flowing pellets can be produced.After the pelletizing process, in order to obtain a satisfactory result, / It is necessary that at least 0.1% of the disintegration accelerator remains based on the weight of the remer.Thus, the advantages of the one-step disintegration addition method described in connection with the prior patents are retained, and the disadvantages are substantial. It was canceled and the money was lost.

The present invention can be applied to the production and processing of propylene.

The present invention is also applicable to processing waste polypropylene materials for reuse in film and fiber formation. It will be appreciated by those skilled in the art that optimal operating conditions and concentrations will depend on the properties of the polymer used and the extreme properties desired by the processor.

The /IJ propylene produced is generally about 2! ; O
High noodle weight average molecular weight ranging from M to 300M and about IO to /! It has a molecular weight distribution of f. For high-speed spinning and fiber formation (IJ globylene has a weight average molecular weight distribution of approximately λ, S to 4.5. However, as the molecular weight decreases below 130M, polypropylene resins can be made into pellets at a commercial level. It becomes difficult to process. When the viscosity of the polymer is removed, unformed particles are created that are difficult to transport and handle. Therefore, manufacturers have to prepare the polymer before shipping to ensure that the molecular weight does not fall below approximately 760M. A number of disintegration promoters are used to achieve the above degrees of disintegration in the R-letting equipment, and these tend to limit the disintegration action of the polypropylene. It undergoes a full-scale reaction under conditions in which the agent decomposes at varying rates depending on temperature and surroundings. The rate of decomposition is defined by the half-life.

According to the present invention, the half-life in polypropylene is /qO
The flaky islands produced by the reactor have a molecular weight - reamer of a free radical source disintegrator with a value of greater than 30 seconds at , 6°C in an amount sufficient to produce the final four-reamer properties desired by the polymer processor. Add to Propylene I remer. Either a disintegration accelerator with a short half-life of 1 is used, or a large amount of disintegration accelerator (if it is necessary to remain unreacted throughout the retization process, the disintegration accelerator can be used in molten form,
P IJ Mama - just inject into the flow. Since it is necessary to uniformly disperse the disintegration accelerator to obtain the best effect, it is necessary to perform a mixing process after injecting the disintegration accelerator. Disintegration accelerators are commonly used and should not interfere with or conversely interfere with the riderovirene stabilizer and should not affect the free radicals that initiate polypropylene disintegration upon decomposition. It must be something that can be generated in a realistic manner. However, the disintegration accelerator must have a half-life of sufficient Km at the re-extrusion temperature at the processor to be substantially totally reacted before exiting the extruder. The half-life of the disintegration accelerator in /IJ glopyrene is -t1
The disintegration promoter should be heated in less than 10 seconds at 100 g° C. so that at least 99% of the disintegration promoter in the pellets has reacted by the time the extruder rod residence time of 7 minutes at this temperature is less than 10 seconds. Such decay accelerators include, by way of non-limiting example, the following compounds: That is, 3-dimethyl λS bis-(
t-butylperoxy)hexyne-3 and goomethyl<4
t-7” tyloyloxy-24tanone (e.g. H'Pe
nws l tCorporat ton's Lucld
ol r) lvlslon Rootstersilua, 30 and Rootskusol/, 2θ), 3, sold by Hansei.
Mum 9? --e enthamethyl-3-(ethyl acetate)-1L
ll,! ;-Texitroxy cyclononane (Wlf
USP-73g sold by Chemical Corporation Non-g), U-S-dimethyl-,2,5-bis-
(t-butylyloxy)hexane (e.g. Gelunosol/θ/) and /-3-bis-(tert-butylyloxyisopropyl)-benzene (Hereuies, In
c.

This is Valukatsude R), a carpenter. Among the compounds in question, WlfCOUSP-/3g and Rootskusol/30 are most preferred. Preferred concentrations of the saponified base disintegration promoter range from about 0.0% to O.lI% based on the weight of the poly-i-. Preferably, the pelletizer operates to retain at least 5% of the disintegration promoter added to the pellet. When the polymer user applies the polymer to the extruder, the conduit restarts the disintegration of the 4-rimer and proceeds to the desired extent to substantially complete reaction in the re-extrusion step. The extruder temperature generally takes about 237.
It ranges from g°C to 2g/6g°C. These conditions also apply to disintegration effects in the extruder die assembly.

In the following example, a melt index measurement device [(^STM723g
') is used to find the melt index. The samples were heated for S minutes to reach equilibrium before testing. Melt index is 1r gain 2. / 70 from lII+ tubules
It is expressed as 9#j of the amount dispensed per minute.

Example 1 A flake with a lower sol index value was obtained in a polypropylene reactor. 0.173% by weight of Loupersol/30 was added to the flakes to prepare a homogeneous blend. This formulation was operated at 79a6C (fed into pellets using a pelletizer with a residence time of about 2 minutes. Theoretically, about 22% of the peroxide had reacted. The melt index of the pellets was measured. As a result, it was found to have a melt index of 33. In the melt index meter, approximately 10 of the disintegration accelerator in the beretsu
% has reacted, so the actual melt index of the pellet is between lIO and 11. It is considered to be in the range of Ii'.

This polymer was easily converted into pellets. The resulting polymer pellets were comparable to normal commercially available pellets.

Next, these pellets were subjected to a re-extrusion process at a temperature of 2.37 IC and a residence time of about 3 minutes in the extruder, and the melt index of the artifact was measured, and a value of about S5θ was obtained. 2.37 To prove that the IC extrusion process has no effect on the melt index, the extrudate was reextruded and the melt index was! It had risen from 3θ to 5θ. Therefore, about 93 g of the increase in melt index was due to the disintegration promoter in the pellets and about 3 arcs was due to the action of the extruder.

The same flakes and equipment as in Example 1 were used. However, the difference from Example 1 was that A3 Lunodarsol/30 was added to the flakes. As a result of measurement, it was found that the melt index of the pellets was 1I3 to jθ. The extrudate during the re-extrusion process was found to have a melt index of approximately 440. As in Example 1, the cutting properties of the pellets were commercially satisfactory and self-sufficient.

Example 3 Wltco Ch*m1oalυsr-/3g-t was applied to the flakes at a concentration of a3j weight above. This formulation was heated to temperature/90.1. C. The extruder was subjected to an extrusion process with an extruder residence time of about - minutes. The melt index of the extruded sample is the result of measurement! It turned out to be. Temperature: l! ; i7c, when re-extruded with a residence time of 3 minutes, the zeta melt index was 2/
A value of 3 was measured. Nine thin sections processed according to the above method without the addition of peroxides can be measured for their mel index.

Example 2% Roux A-Sol/30 tH@rcules PC
- A commercially available polyg called Deku-J is blended with W pyrene pellets, and then this blend is heated at a temperature of 70C and a residence time of 7.
It was then subjected to an extrusion process. Theoretically, the peroxide glue would remain in the extrudate without reacting.Next, this peroxide-enriched extrudate was blended into prozelene pellets in various proportions. did. A theoretical equivalent of pure peroxide was added to the other Beretz F. These "concentrates"/resolution formulations and liquid peroxide formulations were extruded separately using a Plabenme extruder at a temperature of 2'IQIC and a residence time of 7 minutes.
I put it on. The viscosity of the extruder (from the tip of the extruder) was measured and the values are shown in Figure 1.It can be seen that both are equivalent.

Thus, the present invention includes a concentrate of non-disintegration accelerators.

Disintegration accelerator concentrations up to 3% by weight can be easily formed;
It is also possible to form high concentrations of disintegration and accelerators.

While not limiting the invention to any fixed theory, it is possible to assume the significance of the characteristics of a particular disintegration accelerator, and the half-life kinetic coefficient can be determined from half-life calculations. It can be seen that the law is approximately followed.

That is, 1n is m-""' + Tei θ-tei (Lupersol 130) Ding tn is -717"-+4tll, January - Parsol 10
/) However, the half-life reaction rate coefficient per minute in polyzotetrapyrene, T■ Absolute temperature.

It depends on the amount of unreacted disintegration accelerator after a certain period of time, determined by the following two steps.

C^・ However, CA! Concentration of unreacted disintegrant.

For example, when comparing the unreacted rate after 7 minutes of CO/OC (#g'3°K), the initial concentration of the CAo enrichment disintegration accelerator is determined to be only 70%. On the other hand, if the root mother is Sol/, 10, it is 50%.
become.

In addition, it is found that the viscosity of the 7/9 mer exiting the device can be predicted by the following equation:

CR to l,, fo + μ μ however μ = Exit the device after chemical breakdown / IJ mom - viscosity.

μζ Viscosity of the I-remer that leaves the device without chemical breakdown.

Chemical decay efficiency coefficient.

The amount of disintegration accelerator that reacts upon exiting the CR-rich device.

Note that since OR Tomi CAO-C^, by applying the equation to the above equation, we obtain 1--Lc, + cA (/-*- set) μ μ.

Therefore, considering a constant constant (CAo), the ultimate viscosity of 49mer is related to the disintegration promoter used (after a long reaction time it will all be the same), but the correlation between viscosity and time is The reaction rate coefficient depends on 0 e.g.
Figure 1 shows 0.00 &pois@'''1 (e.g. JLldk
Initial viscosity of the polymer when carrying out the pelletizing/extrusion process at C^ and C077C/0.0
Figure 7 shows the relationship between time and flow rate I liglobilene 4 remer viscosity based on 00/Az. The intrinsic viscosity of the Lunosol/3θ sample and the Lunosol 10 sample are almost the same;
O(/% “C” ij lk -74-zo/, 3
It has been proven that θ is approximately twice as large as A//θ/.

When a disintegration accelerator with a short half-life is used, the viscosity of the propylene stream when it leaves the pelletizer after a residence time of 10 min is only 6 ml of that of Leu I4-sol 10/.
7%, and only 30% of Roots Sol 130. Thus Luno-Sol/.30 is most preferred.

In the case of Luno-Sol/3θ, approximately 〃- of the disintegration accelerator may remain after the pelletizing process.

There is almost no danger in handling the produced primer, which has a very low initial loading, and the re-extrusion process requires few processing conditions and λ is 237 gC. At this concentration, which is generally the case, the half-life of Luno-Sol/3θ exceeds 67 minutes, so there is virtually no residual disintegration accelerator after the re-extrusion process, and the retention time For example, if the peroxide in the pellets is only 23 minutes, only 0000017% of the peroxide in the pellets will remain in the extrudate. 30, the processor's extrusion equipment
The extruder residence time is 1000 ml, and the concentration of Lu Yasol/30 in the polymer exiting the extruder is less than 1'L/ppb.

SUMMARY OF THE INVENTION In accordance with the present invention, polymer manufacturers can easily pelletize the pellets, while significantly improving the pelletizing capabilities of processors, and producing pellets that fully satisfy the above objectives and advantages. What is provided is a polymer composition that allows the process to be improved.

[Brief explanation of drawings]

FIG. 1 is a graph showing the correlation between the reaction time and viscosity at the extrusion temperature of propylene used in Example t of the disintegration accelerator according to the present invention.

Claims (1)

[Scope of Claims] (1) A method for preparing lipulpyrene having a large weight average molecular weight of 72;
&? adding a free radical source decay accelerator having a value greater than 0.3 min at a temperature of (/qθ, 6°C), and pelletizing the I remer, which A method for processing 4-liderobyrene, comprising: a pelletizing step carried out under conditions such that a disintegration accelerator of .0/wt. is left behind and further disintegrates. (2) A low viscosity globylene suitable for substantially complete reaction of the residual disintegration accelerator to form a film and *miscellaneous? Claim #11 W?Min's method (3) The polypropylene contains a pre-P disintegration accelerator, comprising the step of extruding the pre-prepared pelletized polymer under conditions that produce remer. Approximately 2.ff4θθ before adding
Weight average molecules ranging from O to so o, o o o! and a molecular weight distribution of from about 10 to about 1/S (method according to claim 11). The method according to paragraph (1) of claim 1, characterized in that the disintegration accelerator is added in an amount of 0.069% and the remaining portion is up to 7% of the disintegration accelerator. When the disintegration accelerator has substantially completely reacted, the propylene 4-limer has a molecular weight distribution of about 2J to
Claim No.
2) Method described in section 2). (6) The disintegration accelerator comprises 2. S-dimethylruco, S-bis-(t-butylperoxy)hexyne-3 and him3゜4
De9-pentamethyl-3-(ethyl acetate)-l Yuken! −
The method according to claim (1), characterized in that it is selected from texitroxycyclononane. (7) The method according to claim (4), characterized in that the residual portion is up to 0% of the disintegration accelerator. (sl approx. 2k (2000~!r00000f)#
A step of preparing 4-riderobyrene having a weight average molecular weight of WKIb and a molecular weight distribution of about IO to /S, adding s-dimethyl-λS bis-(1-butyl 4 g xy) hexyne-3 and tFt &amp; -3-(Ethyl acetate)'>-IQ@! - adding a disintegration accelerator selected from texitroxycyclononane in an amount of about 0.0/-0.7% by weight of said polymer, and at least about □ about 7% of said disintegration accelerator; Processing method for polypyrene 0 (91/ ? Oda℃ me A polypropylene pellet containing a free radical source decay accelerator having a half-life in polypropylene of θ, where the disintegration accelerator is 2,3-dimethyl-2,tbis-
(,t-butyl-e-4xy)hexyne-3 and at49
:? --e enthamethyl-3-(ethyl acetate)-<zqs
- texitroxycyclononane and $1
I-lipropylene pellet O according to claim 9, characterized in that it is present in an amount of at least 0.0/% with respect to the weight of 7 ff-