JPS5849730A - Preparation of polyolefin foam - Google Patents

Abstract

PURPOSE:To obtain the titled highly expanded foam having improved heat resistance, flexibility, resilience and surface beautifulness, by using a specific polyolefin mixture containing propylene-ethylene copolymer essentially and a volatile foaming agent. CONSTITUTION:A mixture of 80-99wt% propylene (P)-ethylene (E) block copolymer having 5-15% (E) content and 0.5-20 melt index (MI) with 1-20wt% P-E-butene random copolymer having 0.5-10% (E) content, 0.5-10% butene content and 2-10 (MI) is used to give the aimed foam by the noncrosslinking extrusion foaming method. The P-E block copolymer is obtained by polymerizing only (P) first in the presence of a stereoregular catalyst, and polymerizing (E), etc.

Description

[Detailed Description of the Invention] This invention relates to a method for producing a foam with heat resistance greatly improved compared to conventional polyolefin 2 ohms. In the method for producing polyoleain 2 ohm by extruding a pressurized molten polyoleain resin containing an agent into a low-temperature, low-pressure section, the polyoleain resin has an ethylene content of 5 to 15% and a melt index of ME or 10 birene-ethylene polyolefin having an ethylene content of 5 to 20. ptsuku 1
Zeng body 80~991[*% and ethylene content a5~10%
Butene content semi-α 5-10%, melt index M I
It is a mixture of 1 to 201% by weight of 2 to 10 random ternary elements of boopylene-ethylene-butene. Foam molding or Inshutosa 11.
The 7t^#;111I polyolefin resin, which has excellent heat resistance, is highly foamed using the non-crosslinking extrusion method.
Moreover, the polyolefin is made of a polyolefin having 2 ohms of flexibility, 1 elasticity, and 2 ohms of surface properties.

The conventional non-crosslinking extrusion foaming method involves press-feeding the extruder into the extruder midway through the extruder, melting and mixing it, and then extruding it to a low-temperature, low-pressure region to foam at a temperature that is within the temperature range suitable for foam molding. Foams mainly composed of low-crystalline low-density polyethylene or non-grade polystyrene are widely used for purposes such as insulation, joint materials, and rental materials because they are relatively easy to mold. However, due to the nature of the raw resin, the heat resistance temperature is low, and the practical maximum temperature is 100℃ or less, so there is a drawback that it cannot be used at high temperatures.It is used for higher temperature applications. These are the steps of the cross-linking foaming process, in which a pyrolytic blowing agent, crystalline polyolefin, and peroxide are mixed in advance, formed into a sheet, and foamed in a heating furnace. There are several stages, and it is quite expensive. In addition, high-temperature foams include isocyanurated polyurethane foam and phenol 2-ohm foam, but ``all of these are hard type 69, and are commonly used as insulation materials for curved surfaces and irregularly curved piping systems.
! ! In addition, highly crystalline polyolefin was extruded from an extruder together with an organic solvent blowing agent or a pyrolytic blowing agent to obtain a specific gravity of α1 to 18.
Methods for obtaining foams of approximately 7 ohm are known in the art.This foam is in the field of so-called structural 7 ohm foams, and the present invention aims to obtain flexible high foams intended for use as rigid structural members.・Compared to low-crystalline or amorphous fats with low softening points such as low-density polyethylene and polystyrene, crystalline fallen fats with low softening points such as high-density polyethylene and polypropylene are Due to the extremely large change in viscosity of the melt near the foaming temperature and the heat of crystallization, it is pushed into the low temperature and low pressure region.
-41! The viscoelastic changes in the fat are extremely large, and the temperature range suitable for foaming is extremely narrow, so it is a national problem to obtain a foam with a beautiful and homogeneous cell structure at a high magnification. friend. 1. In view of the above-mentioned problems, the present invention has been made to produce a polyolefin 7 ohm with excellent heat resistance, flexibility, elasticity, and surface beauty. 10 pyrene-ethylene block with extremely high melting point 1
Foams with good flexibility and elasticity can be obtained for resins with a certain range of ethylene content and Ml. It has been found that by blending a small amount of Ml with a resin larger than the above block copolymer, the surface beauty and elasticity can be greatly improved and the following foam can be obtained. Pressure-fused polyon 2 containing a blowing agent of
In the method for producing polyolefin 7 ohm, which is produced by extruding polyolefin resin to a low temperature and low pressure section, polyolefin 4/
The melt index ME is (L5~20 propylene-ethylene block copolymer 80~99%) and the ethylene content is 5~10%.
, butene content [L5-10%, melt index M
I2) A method for producing polyolefin 2ohm characterized by 1 being a mixture of 12 to 10 propylene-ethylene-butene random ternary co-me forms with 1% to 20 irises 0 of the present invention In the presence of a stereoregular catalyst, the propylene-ethylene block copolymer used as the main component is produced by converting only propylene to t1 in the first step, and adding ethylene or both ethylene and propylene in the second R step. It is obtained by copolymerizing ethylene/globylene in the second step and ethylene/globylene in the third step. When the fractured wfT surface of 11R fat is observed with electron SaW, the structure is found to be scattered in the sea of polyethylene into islands of polyethylene or spheres with particle diameters of 10 to 50μ, forming a spheroidal structure.OThis L5η sea-island structure Because of this, the globylene-ethylene polymer has higher elasticity (impact resistance) than polyglobylene homopolymer, and its melting point is close to that of polypropylene, which is equivalent to the sea. Globylene-ethylene random copolymer which does not have the above structure has both blocks! By the way, the melting peak with more than half of the total heat of fusion based on differential scanning calorimetry (DSC) analysis was found at a heating rate of 5°C/min for polypropylene homopolymer - 160°C, containing ethylene. Globylene-ethylene block copolymer 1 with a ratio of 10%
58℃, 10pyrene-ethylene random copolymer with 6% ethylene content, 130℃・Flexible and elastic;
Moreover, it has excellent heat resistance n, 7? , the foam is obtained as a 41I wood because of the above reasons, 1 rig μ filtration, - ethylene block copolymer is most suitable. This is because the coalescence is poor in heat resistance.〇The propylene-ethylene block copolymer is melted and choreographed in an extruder with a volatile blowing agent, and extruded from the extruder into a low temperature and low pressure region to generate a high expansion ratio. ? 118
Since one unit is manufactured cheaply, 1) only resins with properties in the 6 ranges can be used. In other words, the content of block-bound ethylene is 5 to 15%,
Melt Index MI (23G” CIO min ASTMD
12,58-62T) is a globylene-ethylene block copolymer. The reason for this is that the propylene-ethylene block copolymer in this range becomes viscous and thick at temperatures around the melting point, or the propylene-ethylene block copolymer outside the range
Compared to the ethylene block copolymer, the viscoelastic change of the resin is much more gradual when extruded into the low temperature and low pressure range in a high temperature and high pressure extruder.
Tonaha's friend once said that the temperature range suitable for foaming was wide, and that it had excellent extrusion foaming properties, but it was small.

Globylene-Ethylene block copolymer circle with ethylene content of less than 5%] A 2-ohm made from a 2-ohm body has no elasticity and will not return to its original shape when crushed, and those with an ethylene content of more than 15% are ethylene and propylene. The dispersibility of the foaming agent deteriorates, and 1! % foaming occurred, and it was no longer possible to foam while maintaining the shape.In addition, the melt index was low even if it was made from a globylene-ethylene block copolymer with a content of 5 to 19%. Ml (230°C 10 minutes ASTM D1258
-62T) or smaller than α5 BvIt The surface of the machine has severe irregularities and % off. If it is larger than t20, it may be because the viscosity at the time of foaming is too low. The 2-ohm product made from low-density polyethylene, which has been produced for a long time using the foaming method, is not widely known for its heat resistance, temperature below 100°C, and its elasticity and aesthetic appeal.
,ing. The 92 ohm foam made from the above-mentioned 10-pyrene-ethylene block copolymer had good elasticity (5) and surface smoothness (μ), and had poor surface appearance compared to the foam made from low-density polyethylene. Therefore, we attempted to modify the cypress to improve surface beauty and properties without compromising heat resistance.As a result, we found that the pyrene-ethylene-butene random ternary combination of Ml or 10 was used as the main component. Pyrene-ethylene block copolymer is made from low-density polyethylene or low-density polyethylene by adding 1% more resin.
In addition, it was found that the elasticity was not the same as that of the foam, but the elasticity was also greatly improved.In other words, the melt index Ml (25, O℃ 10 minutes ASTM D1238-
62T) or 2 to 10, resin 1 with an ethylene content a of 5 to 10% and a butene content of α of 5 to 10%! :1~2
The reason for the improvement in surface properties and elasticity of L43 due to the addition of propylene-ethylene diundum ternary copolymers achieved by 0% sweetening is not clear, or perhaps (Ml) Due to the large ME, when blended with small block copolymers, propylene-
Ethylene-butene random merging or appearing on the outside surface n,
I think this is because it contains butene, which greatly reduces the number of foams in both groups and improves the elasticity of 7 ohms.
The foam manufactured in Gankun had good surface beauty but poor elasticity. In addition, the elasticity is further improved with a propylene-ethylene plastic copolymer, and 61M resins include styrene-butene copolymer, polyligten, and ethylene-1.
Ten copolymer is called elastomer (TPE). Whether it's because of compatibility or stupidity, it's completely foamy and 1! No. 90 Therefore, we blended a globylene-ethylene-butene random copolymer with butene into the 10 pyrene-ethylene random copolymer, which has a good surface appearance. Same as above, the foam made from low-density polyethylene is equivalent to the 9-foam, and has improved elasticity. The elasticity of the 10-bill 1-ethylene block of the present invention was poor, and the elasticity of the 1-bill ethylene block of the present invention was similar to the above. body (5-15% ethylene in emergency, MI = [1
5-20) fl, 47m pyrene-ethylene-butene random ternary typical t% is added to the above block copolymer at 1-20% ft,, Ml or 2-10 polyethylene content 15-10% 10%, butene content 0.5-10%
If the resin has a range of 0 or less than 1%, it will have no effect on beauty, and if it is used more than 20%, it will have no effect on elasticity. Similarly, if Ml is smaller than 2, it will have no effect on the beauty of the population, and if it is larger than 1019, the elasticity will deteriorate. If the ethylene content is less than 0.5%, the elasticity will deteriorate, and if it is more than 10%, the compatibility will be poor and foaming will not be possible.Similarly, if the butene content is less than 15%, it will be compatible. 9. Foaming becomes unstable, and if the amount exceeds 10%, surface g!!
Produced by adding a small amount of propylene-ethylene-butene binary ternary co-accumulation to an ethylene block copolymer,
The heat resistance of 7 ohm is δ at 150℃, and it is the same as that of 7t7 ohm when it is manufactured using poly(10 pyrene homopolymer) or only a typical pyrene-ethylene block. Manufacturer 1. The foam has a heat resistance of 150°C, and the heat resistance is inferior to that of the globylene-ethylene block in the present invention.
Sesagi and Globilene-Ethylene-Ptenra/Dam Sangenkyo X
@Integrated mixing 11) The IJ stand is a differential scanning calorimeter (OSC)
This can be easily determined by analysis. In other words, in the DSC chart of the globylene-ethylene block combination, 12
DSC of propylene-ethylene-butene 2nd and ternary copolymerized with a sharp peak of ethylene that sweetens in blocks around 0℃ and a large sharp peak of propylene at 160℃ to 170℃. In the chart, 150℃~1
A gentle peak centered at 50°C was observed.
It is possible to know the choreography allocation from the allocation of 2 and 6 areas to this peak. It is easy to know from the infrared absorption spectrum @4o
That is, the absorption caused by propylene is around 974C1l-'', the blockwise absorption is around 720C1, which is caused by ethylene, and the 6 absorption is around 731C1l-, which is randomly caused by sweetened ethylene.
Absorption 770CII due to randomly thinned butenes
” Determine the transmittance using the baseline method based on the vicinity, and calculate the absorption [A
2A--log-C1ot! The absorbance ratio r Cr=A72o/Atya ) L, 1 ethylene content of propylene-ethylene block copolymer X (X-=J 2 x 100%) to 0IWlat 7
m-Ayi1/At74 and 71=A770/A? 741
9 Globylene 1 Eterene ~ Butene 2 Ndam 3 x 100%
) The unexploded globylene-eletheremp obtained is a typical ivy stick with a small amount of globylene-ethylene-butene random ternary 31
The method for producing a thermally crosslinked extruded foamed foam by mixing 5% is a known non-crosslinked extruded foaming method. Any method may be used.

The screw of the extruder is usually a two-stage type with an L/D of 20 or more, and after the first stage, the foaming agent is pressurized into the pressurized SM in the cylinder from the cylinder of the cow or the second stage, and the screw is inserted into the screw tip area. After passing through a cooling zone of 11t, the foam is extruded into the atmosphere or into a reduced pressure section to form a foam containing a foaming agent of 1e*m.

If 142 extrusion units are used in conjunction, the screw may be of a general full-flight type. The blowing agent is press-fitted between the first extruder and the connecting part of the extruder, and the second extruder is used exclusively for cooling. , Kneadability 11 - The same method as above is also used, 6° resin is usually called a bale forming agent, and 41 fine powder is added to the tri-blend or masterno (fl-b o nucleation) which is fed from the extruder hopper in the form of fl-b o. The agent is a foaming agent and a resin 84sol 19 to form a foaming starting point.
Generally, 1 to 2 parts of Merck, inorganic fine powder such as calcium carbonate, and a mixture of sodium bicarbonate and citric soda are used, but in the present invention, any material may be used. For the purpose of modification, 11 tons of globylene-ethylene-butene random terpolymer from dinner was added to the mixture of propylene and ethylene blocks. It is okay to mix and use other sleeve fats in the Occupi L eel layout. Examples of 11 fats that are conveniently used in choreography include high/medium density polyethylene, low density polyethylene, and Airi Tactic Polyg Tetrapyrene. , active polyglupylene, globylene-ethylene binary copolymer, ethylene or glupylene-vinyl acetate co-condenser, ethylene or propylene-vinyl chloride co-N4! r-isomer, ethylene or globylene-acrylic acid ester A1f%, ethylene or globylene-sterene copolymer% EPDM, polybutadiene, polybutylene, chlorinated polyethylene, chlorinated polyethylene, etc.

Heat stabilizer in the resin mixed with propylene-ethylene-butene random ternary combination.

Antioxidants, ultraviolet absorbers, deactivators, lubricants, skin coloring agents, antistatic agents, etc. W may be added depending on the purpose 0 Foaming agents in carrying out the present invention is a halogen-based, chlorofluorocarbon-based, or alkane-based low-boiling organic solvent, such as methyl chloride, methylene chloride, triccl mono20lomethane, dichloromethane, trichlorotri2oloethane, diku aaf) 970loethane s 7
H, p (butane, pentane, etc.) The present invention will be explained in detail below using Examples and Comparative Examples.Examples 1 to 6 & Comparative Examples 1 to 6 Melt index Ml (250℃10
minute ASTM D123B-627), a woodcutter propylene-ethylene block typical metal resin with an ethylene content (calculated from the infrared absorption spectrum A720/A974) of 97.5% by weight and a melt index MI7.5. Ethylene content 2%, butene content 5% (absorption spectrum by infrared spectroscopy needle A7s1/Avy4* A770
/A? 100] 100] 25% by weight of 10 pyrene-ethylene-butene ternary typical body of 741 calculation) was mixed at the foot of the needle.
Talc (L3. part) was triblended and charged into the tandem-type Oshiyamarei hopper as described below.1
7Ir, 11t, the first extruder with a blowing agent injection hole in the center of the screier (diameter 50 cocoon φL/D=24) i
+ - Consisting of n, connected in series 〇 first press aim
Screw 1- is a full 29-ite type, and the temperature conditions are: supply part: 150°C, compression part: 200°C, 1 needle ftg: 200°C.
Weight 15kg/R4C7! Scratching difference--number of turns 1*
The prepared foaming agent (4,95 Kg/#f) was injected into dichlorotetra 20 loethane using a pressure pump using a pressure pump to give a total weight of 551 parts (4,95 Kg/#f) to 100 μm of resin. It was supplied to the second extruder through the connecting pipe 11.In the second extruder, the screw had a notch in the flight to increase the mixing efficiency. The mixture was extruded into the atmosphere through a pie die with a circular diameter of 5 mm and an outer diameter of a3 sam, and the properties of the foamed pellets are shown in Table 1.

The following is Marinkyo 1 1) 11 Tension ratio: R foam meat N/dice spacing Elasticity: Immediately release the wall thickness ■ after compression, and then melt index M ■ within the range of the present invention from the thickness 1 and a propylene-diterene block with an ethylene content of 1 [coalescence'91: The foam produced from the resin as a product has good foaming properties, good elasticity, and good surface beauty. I understand.

Examples 7-10, Comparative Examples 7-16 Implementation? Using the same extrusion foaming equipment as in IJ 1 to 6, a melt index Ml (230
℃ 10 minutes ASTM D1218-62T), ethylene content, butene content (calculated from infrared absorption spectroscopy by infrared spectroscopy quadruple meter Ayi1/Au7as A770/A974) using propylene-ethylene butene random lI mixed with ternary typical great body or globylene-ethylene random co-'N great body' at a ratio of 51%
Tri-blend 100 parts of fat to 5 parts of talc α, charge it into the extruder hopper, and perform extrusion/II under the conditions of M. Table 2 shows the properties of the 1 and 9 foam rods. Both propylene and ethylene blocks are 1 at the rear 0 thickness 2
4! Of the random composites used by mixing 1251J1% of globylene-ethylene-butene random' ternary typical composite, melt index M within the scope of the present invention was used.
1. It is manufactured from resin with ethylene content and butene content, and has good foam, elasticity, and surface beauty.
C and Kawaga 0 Examples 11-15 and Comparative Examples 17-18 Examples 1-6
Melt index M I using the same extrusion equipment
= 1.0 propylene-ethylene block with 12% ethylene content and melt index MI = 7.
5 ethylene content 2% butene content 5% propylene-
Weigh the mixture distribution of ethylene-butene random ternary compound X compound (6) as shown in Figure 5. A sweetened resin 100
To the east ms, talc (15 m dobe t 2) was blended and put into the extruder hopper, and extruded 1'!i under the same conditions.
Properties of the foam II - 0 shown in Table 3
@ x Terene t * %) B: Poubilene-ethylene y-ptentsimem ternary copolymer (Ml-1 [content rate: 5%) The process shown in Table 5 Within the scope of the present invention, a mixed layout of a propylene-ethylene bulk PPC power supply body and a globule/-ethylene-butene random ternary composite body can be used to obtain a good form within the scope of the present invention. 1 Based on Example 11j? Process Comparative Examples 19 to 23 Using the same extrusion foaming device II as in Examples 1 to 6, and having the process shown in Table 4, 1) Low-density polyethylene 2)
Polyglobylene hosopolymer 3) Glupylene-ethylene block co-J [sweet% 4) Globylene-ethylene-butene 2ndam ternary copolymer, 5) Globylene-ethylene block 2
Figure 1 shows the properties of a typical PII foam.

5) and 4) kg25/7.5 sweetened ycll fat 6)-foamed 7 ohm properties were compared. To prevent thermal decomposition during the heat resistance test, the resin was treated with an anti-linear agent, pentaerythrityltetrakis (5-15-di-butyl-4-hydroxyphenol), globionate 11, 100-gold resin, α4st for the neck part, and a nucleating agent, talc α2s. It was used as a tri-blend.

411Mk press tBiiL', blowing agent dichloronat 22
The pressing force of 0roethane was the same as in Examples 1 to 6.The conditions were the same as in Examples 1 to 6 for all 6 hinoki in the first extruder, and the temperature of the cooling oil in the oil jacket of the second extruder was 1. ) or 8
5℃ 2) or 135℃ 3) 6) or 150℃ 4) 5)
The properties of the cypress foam obtained at 100°C are shown in Translation 4.

The obtained foams were heated in a high temperature atmosphere for 1,000 hours, and the atmospheric temperature at 10% FC was measured as a measure of heat resistance. did. This result is also shown in Table 4 as 1) 3) 3) 4) S) 6) Book Elasticity:! I #Mi ays fight is compressed by 1 area per 1 coffin and the 9th O mackerel retention rate Oso ++xoo% m
go less than +1-ao% QaO ~ less than meeting o% ×
o ~ Less than 60% Thorn 4 The foam of the present invention has a low specific gravity, 5 elasticity, Table 11O moxibustion brittleness comparable to that of low density polyethylene 7 ohm, and heat resistance of 150°C. I understand Procedural amendment (voluntary) January 1980 e Japan Patent Office Commissioner 1 Display of case 1982 Patent Application No. 148628 2 Name of invention 3 Method of packing polyolefin 7 ohm 3 Person making the amendment Related Patent Applicant Name: +445+4th Agent, Hitachi Chemical Co., Ltd. (250J).

2nd line 5th line from the bottom of No. 15 K “Street fat usually formed wound”
There is a statement [Corrected to say ``Resin is usually a nucleating agent''.

Claims (1)

[Claims] 1. Polyolein produced by extruding a pressurized m-melt polyolein resin containing a volatile blowing agent into a low-temperature, low-pressure section 2.
In Ohm's manufacturing method, the polyolein resin has an ethylene content of 5 to 15% and a melt index of Ml or α5.
~ 20 pieces of polyethylene pineapple combination 80~
99] [Amount % and ethylene content α 5-10%, globylene-ethylene-butene random ternary with melt index M1 or 2-10 1 @ integral 1-20 Jl [Amount % It is a mixture of I! - A method for producing characterized polyolein 2 ohm.