JPS6017420B2 - Method for manufacturing polyester elastomer foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polyester elastomer foam having a high magnification and a uniform and fine closed cell structure.

The field of plastic foams has shown significant progress in recent years,
Foams such as polystyrene, polyvinyl chloride, polyethylene, and polypropylene are widely used in building materials, packaging materials, etc. due to their flexibility, lightness, and heat insulation properties.

However, these foams have problems in terms of mechanical strength, elastic recovery, cold resistance, heat resistance, etc. Foams such as rubber, polyurethane, and ethylene-monoacetate-pinyl copolymer are also known as foams with relatively excellent elastic recovery properties.
However, rubber, polyurethane, etc. have extremely poor aging resistance, and only open-celled cells can be obtained, and closed-celled ones are difficult to obtain.
It cannot be made into a highly foamed material that satisfies mechanical properties such as tear strength. On the other hand, ethylene-vinyl acetate copolymers can be made into highly foamed materials with relatively excellent compressive strength and tear strength, but they are still insufficient in terms of elastic recovery (anti-twill elasticity). However, it has a defect in that it cannot withstand use at high temperatures, especially in terms of heat resistance. The characteristics of these conventional foams are determined by both the properties of the base polymer and the form of foaming (eg, uniformity, closed cell nature, etc.). On the other hand, polyester elastomer is known to have excellent mechanical strength, elastic recovery, rebound resilience, cold to heat resistance, oil and cold resistance, and is expected to be a useful foam base material. sell. The extrusion foaming method (Japanese Unexamined Patent Publication No. 49-197872) is known as a technique for making such a polyester elastomer into a foam, but in order to foam at the same time as melt extrusion, a special device is required for the molding die. Otherwise, you will not be able to obtain a molded product with the desired shape and size. It is extremely difficult to produce homogeneous closed cell foams.
Therefore, the general practice is to mold the foam into a large foam block and cut it as appropriate for use, but this method does not provide uniformity in quality. As an improvement to this melt extrusion foaming method, the foaming agent is not decomposed and foamed during molding, but is foamed in the mold after molding (
However, in this method, in order to keep the viscosity of the polymer high during decomposition and foaming, decomposition and foaming must be carried out very close to the melting point of the polymer, and fine and uniform It is difficult to obtain a foam having a foamed structure, and even more so, it is extremely difficult to obtain a highly foamed product.
The inventors of the present invention have conducted various studies on methods for producing block polyether ester foams, and have found that they have been able to eliminate these disadvantages and easily produce high-performance foams that have a homogeneous, fine, closed-cell cell structure. We have arrived at the present invention as a manufacturing method.

That is, the present invention is composed of a poly(alkylene oxide) glycol having a number average molecular weight of 500 to 6,000 and a dicarboxylic acid having a molecular weight of 350 or less to 20 to 8 parts by weight of short chain polyester units of which 50 mol% or more is composed of polybutylene terephthalate units. 80~
Melting point 100-22 obtained by copolymerizing in a ratio of 2 parts by weight
A blowing agent and an organic peroxide which has a lower decomposition temperature than the blowing agent and which causes crosslinking to the flock polyether ester are blended into 0qo block polyether ester and heated. By decomposing the organic peroxide to generate crosslinks in the block polyether ester to the extent that fluidity is not lost, and then decomposing and gasifying the blowing agent to expand it. A method of manufacturing polyester elastomer foam is provided.

According to the method of the present invention, since the block polyether ester is chemically crosslinked with an organic peroxide, it can be foamed with appropriate fluidity over a wide temperature range.
As a result, a homogeneous, closed-cell, highly foamed material is obtained. Conventionally, it has not been known that polyesters such as polyethylene terephthalate and polybutylene terephthalate can be efficiently crosslinked with organic peroxides, and of course this The significance of the present invention can be seen from the fact that it has not been known to produce highly foamed materials by this method.

The present invention mainly consists of butylene terephthalate units and poly(
For the first time, block polyether esters composed of glycol units (alkylene oxide) can be effectively treated with organic peroxides, leading to polyester elastomer foams with excellent performance. The block polyether ester used in the present invention has short chain polyester units as hard segments and long chain polyether ester units as soft segments,
It is a so-called thermoplastic elastomer that behaves like a normal thermoplastic polymer when melted, but when solidified, the short chain polyester hard segments crystallize to form a type of physical crosslinked structure and exhibit rubber elasticity. It is.

Here, in the short chain polyester unit, the main components of the dicarboxylic acid component and the diol component are terephthalic acid and monomer.
, 4-butanediol, and at least 50% mole of it must be butylene terephthalate units, which results in excellent moldability, mechanical strength, rubber elasticity, heat resistance, etc. . Note that dicarboxylic acids other than terephthalic acid can be used as copolymerization components as dicarboxylic brewing components, and such copolymerization components include dicarboxylic acids having 2 to 20 carbon atoms such as azelaic acid, sebacic acid, adipic acid, and decanedicarboxylic acid. Examples include aliphatic dicarboxylic acids, aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, and naphthalene dicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and the amount that can be copolymerized is up to 50 mol% of the total dicarboxylic acid components. It is. Particularly preferably used copolymerized dicarboxylic acid component is isophthalic acid, where terephthalic acid/isophthalic acid = 9
0-50/10-50 (molar ratio), more preferably 80
When used in a ratio of 50/20 to 50 (molar ratio), suitable results are obtained as a crosslinked foam of polyester elastomer. The diol component is essentially 1,4-phthanediol, but if a small amount is copolymerized, other aliphatic diols such as ethylene glycol, propylene glycol, neobentyl glycol, 1,5-bentanediol, 1,6 - Alicyclic diols such as hexanediol, decamethylene glycol and cyclohexanedimethanol may also be used. The long chain polyether ester unit in the block polyether ester has a molecular weight of 35
Dicarboxylic brewing component of 0 or less and number average molecular weight of 500 to 6
000 long chain diol component, and this dicarboxylic brewing component is substantially the same as the dicarboxylic brewing component of the short chain polyester unit.

Poly(alkylene oxide) glycols that react with dicarboxylic acid components to form long-chain polyether ester soft segments include polyethylene glycol,
poly(1,2- and 1,3-propylene oxide) glycol, poly(tetramethylene oxide) glycol, poly(hexamethylene oxide) glycol, block or random copolymers of ethylene oxide and propylene oxide, flocs of ethylene oxide and tetrahydrofuran or Examples include random copolymers, among which poly(tetramethylene oxide) has excellent heat resistance, water resistance, mechanical strength, elastic recovery, and crosslinking reactivity with peroxides.
Glycols are preferred. The number average molecular weight of poly(alkylene oxide) glycol is 500 to 6,000, more preferably 800 to 3,000. The block copolyether ester produced using poly(alkylene oxide) glycol having a molecular weight in this range forms a stable microphase separation region, exhibits good rubber elasticity, and makes the polymer flexible. If the molecular weight is too small, or conversely too large, it is undesirable as it impairs rubber elasticity and lowers mechanical strength. Furthermore, depending on the case, polyfunctional components such as trifunctional or higher functional polycarboxylic acids, polyols, and polyoxycarboxylic acids may be added to the block polyether ester, and by adding such polyfunctional components, the melt viscosity can be increased. It is also possible to make the production of crosslinked foams easier due to the increase in .

The amount of the polyfunctional component that can be added is 0.05 to 3.0 mol% based on the dicarboxylic acid and diol forming the polymer. Things that can be used as polyfunctional components include:
trimellitic acid, trimesic acid, pyromellitic acid, 3,
3',4,4'-penzophenonetetracarboxylic acid, 1
, 2,3,4-butanetetracarboxylic acid and their acid esters, derivatives such as acid anhydrides, glycerin, bentaerythritol, sorbitol, and the like. However, the contribution of this polyfunctional component to the crosslinking part of the "chemically crosslinked" foam, which is the gist of the present invention, is extremely small, and the actual method of introducing crosslinking is carried out by a different method as described later. There is a need. The block polyether ester used in the present invention is substantially composed of the above-described short polyester units and the longest chain polyether units, and is composed of short chain polyester units and long chain polyether units. The Stell units occupy a weight ratio of 20 to 8 and 0 to 20.

A particularly preferred composition is that the short mirror polyester unit is polybutylene terephthalate or polybutylene terephthalate no polybutylene isophthalate copolymer, and in the poly(alkylene oxide) glycol of the last chain polyester unit, poly(tetramethylene oxide) is used. It consists of glycol. Defining a particularly preferable range of these copolymerization composition ratios differs depending on the use of the foam, but for applications that strongly require flexibility and high elastic recovery, the most preferable range of polyester ester units in the last chain should be 35 to 8% by weight. In particular, those containing 40 to 7% by weight are preferred, and for applications that strongly require high mechanical strength, heat resistance, chemical resistance, etc., 20 to 5% by weight, especially 25 to 5% by weight of long mirror IJ ether ester units are preferred. Preferably, it contains 40% by weight. The method for producing the block polyether ester comprising these components is arbitrary, but one example of a suitable polymerization method is to add dimethyl ester of dicarboxylic acid to an excess of about 1.2 to 2.0 molar amount relative to the acid. molar of low molecular weight glycol and poly(alkylene oxide) glycol in the presence of a conventional esterification catalyst at a temperature of about 150 to 25 mm under normal pressure, transesterification is carried out to distill methanol. , then under reduced pressure on the 5th side for 20 minutes.
It can be produced by heating polycondensation at 0 to 270°C.

The block polyether ester thus produced has a logarithmic viscosity of 0.5 or more, preferably 0.7 or more. Moreover, the block polyether ester of the present invention has about 10
It is sufficient to have a melting point of 0 to 220,000, but in order to achieve the purpose of thickening the blowing agent and foaming it after crosslinking to obtain a uniform highly foamed product, it is necessary to have a melting point below the decomposition temperature of the blowing agent. The melting point range is preferably 120 to 1.
The temperature is 65°C.

In order to achieve this purpose, as described above, the short chain polyester unit of the flocked polyether ester is composed of butylene terephthalate/butylene isophthalate = 90/10 to
It is preferable that the copolymerization ratio is more preferably 80/20 to 50/50 than 50/50. In addition, other polymeric substances may be mixed with the block polyester ester in a proportion of 5% by weight or less of the total weight for political purposes.

Such polymeric substances include polyethylene, ethylene-vinyl acetate copolymer, ethylenenopropylene copolymer, ethylene-acrylic acid copolymer, polypropylene, chlorinated polyethylene, and chlorinated polyp. Examples include pyrene, polyvinyl chloride, polyester, polyamide, polyurethane, styrene-butadiene copolymer, and acrylonitrile-butadiene copolymer. In addition, various stabilizers such as heat stabilizers, antioxidants, hydrolysis stabilizers, and light stabilizers, colorants (pigments, dyes), and antistatic agents may be added to the block polyether ester as long as they do not interfere with crosslinking or foaming. Organic or inorganic additives such as additives, conductive agents, key fuel agents, reinforcing materials, fillers, adhesives, and plasticizers can be used in combination. The addition may also take place during the polymerization of the block polyether ester. The blowing agent used in the present invention is a thermally decomposable blowing agent that decomposes and generates gas when heated, such as inorganic blowing agents such as sodium bicarbonate and ammonium carbonate, azodicarbonamide, azobisisobutyronitrile, and diazoamino blowing agents. Examples of organic blowing agents include benzene, azodicarboxylic acid metal salts, dinitrosobentamethylenetetramine, hydrazizocarbonamide, diethyldinitroterephthalimide, p-toluenesulfonyl semicarbamide, s-trihydrazinotriazine, and bisbenzenesulfonylhydrazide. However, it is necessary to have a decomposition temperature substantially higher than that of the organic peroxide, and azodicarbonamide and dinitrosobentamethylenetetramine are particularly preferred.

These foaming agents are used in a range of 0.1 to 40% by weight based on the block polyether ester, and the mixing amount can be arbitrarily changed depending on the type and the desired expansion ratio. For example, when the purpose is to use it as a so-called foam, the mixing amount is 5 to 4% by weight, preferably 10 to 4% by weight.
It is 25% by weight, and when made into a foam with a low expansion ratio for the purpose of weight reduction, high treadability recovery, and improvement of permanent deformation resistance, with the aim of respecting the quality of block polyether ester as an elastomer. The mixing amount is selected in the range of 0.1 to 10% by weight, preferably 0.5 to 5% by weight.

In the present invention, it is essential to weave the Ib-based frame.

In general, when foaming thermoplastic resins, in order to obtain a good foam, especially a highly foamed product, it is necessary to have a viscoelastic flow region that promotes uniform dispersion of gas at the foaming temperature and prevents it from dissipating out of the system. is necessary. However, in the case of crystalline polymers, when the melting point of the polymer is exceeded, it becomes thermoplastic and the melt viscosity decreases with temperature, and especially in polymers with a small molecular weight compared to olefins such as block polyether esters, the melt viscosity is remarkable. shows a decrease in Therefore, the temperature range in which viscoelastic behavior suitable for foaming is exhibited is extremely narrow, and it is impossible to obtain a highly foamed product having homogeneous and fine foams.

However, by introducing cross-linking into the block polyether ester using an organic peroxide, it is possible to obtain a modified block polyether ester having a viscoelastic flow region suitable for foaming as described above. The organic peroxide used in the present invention has a decomposition temperature substantially lower than that of the blowing agent used simultaneously, and higher than the flow initiation temperature of the block polyether ester.

Especially when the decomposition half-life is 1 minute, the decomposition temperature is 120 pm
Those above are preferred, particularly preferably 150 qo or more. Specific examples include methyl ethyl ketone peroxide (1820), t-butylperoxyisopropyl carbonate (15), dicumyl peroxide (17100), and cumene hydroperoxide (2
55q0), 2,5-dimethyl-2,5-di(t-butylperoxy)hexane (179 ○), 2,5-dimethyl-2,5-di(t-butylperoxy)hexane-3 (19 ○) ), di-t-butyl peroxyphthalate (159qo), etc. These organic peroxides are used in an amount of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the block polyether ester. Such organic peroxides are used to introduce cross-links into block polyether esters; in the present invention, 0.1 liter of the modified polymer sample is mixed with 120 ml of tetralin in 50 ml of tetralin.
The amount of organic peroxide is adjusted so that a crosslinked structure can be introduced such that the weight percent of the unlacquered part when soaked at ℃ for 3 hours is 5% by weight or more, more preferably 10 to 8% by weight. The type should be selected and used. The degree of crosslinking is defined as the insoluble content measured by the method described above. Further, in order to carry out the crosslinking reaction smoothly and efficiently, it is preferable to use a crosslinking accelerator, and when carrying out the present invention, the following two types of agents are particularly preferably used, and each may be used alone or in combination.

First of all, one type has two vinyl-type double bonds in the molecule.
Typical examples include divinylbenzene, diallylbenzene, divinylnaphthalene, divinylpifenyl, divinylcarbazole, divinylpyridine and their nuclear-substituted and near-green homologs, ethylene glycol dimethacrylate, Polyacrylates and polymethacrylates of aromatic polyhydric alcohols such as hydroquinone dimethacrylate; polyvinyl esters and polyallyl esters of aliphatic and aromatic polyhydric carboxylic acids such as divinyl phthalate, diallyl phthalate, diallyl maleate, bisacryloyloxyethyl terephthalate; , polyacryloyloxyalkyl ester, polymethacryloyloxyalkyl ester, diethylene glycol divinyl ether, hydroquinone divinyl ether, bisphenol A diallyl ether, polyvinyl ether and polyacrylic ether of aliphatic and aromatic alcohols, triallyl cyanurate, triallyl. Examples include phosphatate and trisacryloxyethyl phosphate. Furthermore, the aliphatic and aromatic polyhydric alcohols constituting the crosslinking accelerator include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, trimethylolpro/gum, bentaerythritol, and 1,4-butanediol. , poly(
tetramethylene oxide) glycol, 1,6-hexanediol, neobentyl glycol, hydroquinone,
Resorcinol, biphenol, p,p'-dioxybenzophenone, p,p'-dioxyphenyl ether, 1,
4-dioxynaphthalene and its close congeners,
Polyhydric carboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, sebacic acid, adipic acid, itaconic acid, butenetricarboxylic acid, maleic acid, trimellitic acid, pyromellitic acid, trimesic acid and their close homologs. The amount of these crosslinking accelerators added is 0.5 to 2% by weight, preferably 1.5% by weight, based on the block polyether ester.
It is used in a range of 0 to 1% by weight. Some of these crosslinking accelerators exhibit a plasticizing effect during hot molding. Another type of crosslinking accelerator is an aromatic compound having one vinyl group, CH,=CH-Y (Y is an aryl group or a nuclear-substituted aryl group) and an acryloyloxy group or a methacroyloxy group. An organic compound having two or more (R is H or a methyl group, Z is a hydrocarbon group having 2 to 20 carbon atoms,
0. S, P, N, hydrocarbon group containing halogen, n is 2 to
(an integer of 4), and even if either one of these compounds is missing, the crosslinking efficiency will be significantly lowered, and the degree of crosslinking required to make a foam will not be obtained.

Typical examples of the former include styrene, vinyltoluene, ethylpinylbenzene, N-vinylcal/azole,
Vinylcarbazole, vinylnaphthalene, and their nuclear substituted products and near-green homologs are included, and in carrying out the present invention, these compounds are used in an amount of 1 to 4% by weight, preferably 5% by weight, based on the block polyether ester. ~25% by weight is used. The latter compounds include hydroquinone, resorcinol, and pyrogallol. p-oxybenzine alcohol, biphenol, P,p'-dioxyphenyl ether, p
, p'-dioxyphenylethane, bisphenol A,
p,p-dioxybenzophenone, 1,4-pis(2-oxyethoxy)benzene, 1,4-bis(oxymethyl)benzene, 1,4-dioxyanthracene, HOkiCH2(n is 2 to (an integer of 20) polymethylene glycol, diethylene glycol, glycerin, bentaerythritol, bis(oxyethyl) terephthalate, bis(2-oxyethyl) phthalate, bis(3-oxypropyl)adivate, methylolmelamine, dimethylolurea, bis(3-oxypropyl)-2, 3-
There are di-, tri- or tetraacrylates such as dibromoethyl phosphite and di-, tri- or tetramethacrylates. These compounds are used in an amount of 0.5 to 20% by weight, preferably 1 to 1% by weight, based on the block polyether ester. Further, a compound that aids or accelerates crosslinking may be incorporated into the block polyether ester by a method such as copolymerization or chemical modification.

Typical compounds include dicarboxylic acids or diols containing unsaturated groups, polyisocyanates,
It is a polyepoxide compound. For example, dicarboxylic acids or diols containing an unsaturated group in the molecule include 3-(or 4-)hexene-1,2-dicarboxylic acid, 2-cyclohexene-1,4-dicarboxylic acid, and 3-butene-1,2-dicarboxylic acid. acid, allyloxybenzoic acid, 3-(
or 4-) cyclohexene-1,2-dimethanol, 1
-(or 2-) cyclohexene-1,4-dimethanol, 4-allyloxyphenol and their close relatives, preferably 0.01 to 10 mol%, preferably 0.5
It can be copolymerized and used in a range of 5 mol %. The isocyanate compounds are 2,4-tolylene diisocyanate, 2,6-tolyne diisocyanate, 4,4-diphenylmethosodiisocyanate, 4,4'-diphenyl ether diisocyanate, hexamethylene diisocyanate, m- or p- xylylene disocyane
Diisocyanates such as
Contains multimers such as oligomers. These polyisocyanate compounds may be used in the form of derivatives reacted with polyester prepolymers, poly(alkylene oxide) glycols, and the like. Epoxy compounds have one or two epoxy groups in the molecule, such as phenylglycidyl ether, allylglycidyl ether, 3,y-epoxypropyl ether, 1,4-bis(8,y-epoxypropoxy) Butane, 1,6-bis(epoxyethyl)hexane, 2,2-bis[p-(8,y-epoxypropoxy)phenyl]propane, 1-epoxyethyl-3,4-epoxycyclohexane, 1-(3, y-
epoxypropoxy)-2-benzyloxyethane, 1
Examples include -(3,y-epoxypropoxy)2-ethoxyethane, 1,4-bis(8,y-epoxypropoxy)benzene, and particularly preferred are epoxy compounds having the following structure. (However, n is an integer.) The floc polyether ester, blowing agent, crosslinking accelerator, and organic peroxide can be blended by conventionally known mixing methods, such as Banbury mixer, mixing roll, kneading extruder, etc. Mixing can be carried out using a Henschel mixer or the like.

In particular, in order to achieve uniform mixing with additives such as foaming agents, it is preferable to use the block polyether ester in powder form.

Heating in the present invention means, for example, heating at a temperature range that is at least the temperature at which the organic peroxide decomposes and at which the blowing agent does not decompose, for an appropriate period of time, and then further heating at or above the temperature at which the blowing agent decomposes. , or one in which the temperature is gradually or rapidly raised from room temperature to the temperature at which the blowing agent decomposes.

In the present invention, as described above, a composition prepared by blending a block polyether ester with a blowing agent, an organic peroxide, and, if necessary, a crosslinking accelerator, is extruded, calendered,
After molding into a sheet, film, pipe, rod, or other desired shape by compression molding, injection molding, or other suitable methods, the foam can be made into a foam by heating at normal pressure or under pressure.

In such a molding process, the molding temperature is set to be higher than the flow start temperature of the polymer and lower than the thermal decomposition temperature of the blowing agent, more preferably (
The temperature is set at a temperature not lower than the flow start temperature of the polymer + 10 qo) and lower than the thermal decomposition temperature of the blowing agent - 10°C. In particular, when producing a continuous sheet-like foam, it is preferable to knead the foam under the above-mentioned kneading temperature conditions and simultaneously or subsequently form the foam into a sheet by extrusion molding. The foamable block polyether ester crosslinked molded product obtained as described above is heated to a temperature higher than the decomposition temperature of the foaming agent to foam it by an appropriate method.

The heating method may be by heating in a mold, or by conventionally known methods such as hot plate heating, roller heating, air or steam heating, heating in liquid, high frequency heating, or infrared heating method. can be used. In addition, in the method for producing a foam of the present invention, the blended composition is heated under pressure in a closed container and then depressurized to form a foam, instead of heating and foaming the composition after it has undergone a melt-molding process. It is also possible to heat and foam in a closed but not airtight mold.

Since the foam of the present invention obtained in this manner is based on crosslinked block polyether ester, this phenomenon could not be expected in a block polyether ester foam that does not have a substantially cross-linked structure. It is possible to create a foam that includes high magnification, uniform fine closed-cell foam, and has excellent elastic recovery, compressive modulus, breaking strength, cold to heat resistance, aging resistance, and solvent resistance. can.

Moreover, since it can be easily obtained as a continuous sheet, it can be used as a high-performance foam that is not found in conventional olefin-based, rubber-based, or urethane-based foams, and can be used for wall materials, looping, flooring, etc. It is useful as a building material and interior material for automobiles, ships, etc., and as a packaging material. In addition, it is possible to control the foaming ratio by changing the amount of foaming agent added, so of course it is possible to create a foam with a low foaming ratio of about 1.2 to 4 times. How to use: For example, in applications such as packing, gaskets, gears, hinges, and other mechanical parts, precision parts, and covering electric wires and cables, it is lightweight and flexible, and its crosslinked structure provides heat resistance, chemical resistance,
Performance such as compression set resistance can be significantly improved.

The present invention will be specifically explained below using Examples.

In the main text of the specification and in the examples, "part J" or "%" is by weight unless otherwise specified. In the present invention, the logarithmic viscosity is measured in orthochlorophenol at 0.5% and 25o0. Example 1 Dimethyl terephthalate 70. Eaves, 30.0 parts of dimethyl isophthalate, 1,4-butanediol Satoshi. Titanium tetrabutoxide 0.
．． 05 parts into a polymerization reaction vessel equipped with a stainless steel helical ribbon type wing, and heated at 170:00 for 30 minutes.
The methanol produced by heating at 20° C. for 9 minutes was distilled out of the reaction system.

The reaction temperature was then raised to 245° C., the pressure of the system was gradually reduced to 0.2 Hg, and the polymerization reaction was continued at this pressure for an additional 150 minutes, yielding an extremely viscous melt. The logarithmic viscosity of the obtained block polyether ester measured in orthochlorophenol at 25°C at a concentration of 0.5% was 1.30, and the melting point determined by DCS was 146°C. In addition, nozzle 1. Overboard, L/D = 1.0 go 0/min under temperature rise 100k9/
The polymer had fluidity at 137° C. when the temperature at which it began to flow under a heavy load was determined. The thus obtained block polyether ester pellets were cooled with liquid nitrogen and pulverized to obtain a powder with an average grain size of 100 Buddhas.

Block polyether ester 10 parts, azodicarbonamide 1 part, divinylbenzene 3 parts, 2,5-themethyl-2,5-di-t-butylperoxyhexine-3
After mixing 0.3 parts of heat stabilizer and 0.5 parts of heat stabilizer into powder using a Henschel mixer, add 0.4 parts of this mixture to 0.4 parts. 16 with extruder
Beletized at 0qo. The degree of crosslinking of the obtained pellet was 1% or less. Next, the obtained pellet was placed in a sealable mold with a thickness of 2 arcs, and was heated under a pressure of 200 k9/ground to 18
After heating the temperature to 220 qo over a period of minutes, it is foamed at the same time as the pressure is removed.
Kite x 1 A softened foam having uniform white cells was obtained. The apparent density of this foam was 0.04 mm/m, and the degree of crosslinking was 45%. Example 2 Dimethyl terephthalate 50. parts, dimethyl isophthalate 50.0 parts, 1,4
-Butanediol68. In the same manner as in Example 1 using neck and poly(tetramethylene oxide) glycol 8 as starting materials, logarithmic viscosity 1.21 DSC, melting point 12
A block polyether ester having a flow start temperature of 108°C in a flow tester was obtained.

This block polyether ester contains 10 parts of dicumyl peroxide, 0.3 parts of heat stabilizer, and 7 parts of azodicarbonamide at a temperature of 120 to 130°C.
After uniformly dispersing the composition by mulling, the composition was heated to 15,500 m
The peroxide was decomposed by heating for a minute. Continued 190q
The foaming agent was decomposed by heating at 0 for 5 minutes to obtain a foam having uniform fine cells. The apparent density of this foam is 0.
The degree of crosslinking was 78% at 0.45 pm/uniform. Example 3 The amounts of azodicarbonamide, divinylbenzene, and heat stabilizer blended in Example 1 were the same as in Example 1, and 2,5-dimethyl-2,5-di-t-butylperoxy After changing the amount of hexine-3 (organic peroxide) added as shown in Table 1 and thoroughly kneading it with a Henschel mixer, the
The moldings were hot-pressed under ground pressure into a 3-wall thick molding and subsequently kept under these conditions for 10 minutes.

Next, this molded product was cooled, taken out, and heated in a 200 qo heating oven for 10 minutes to foam. In samples in which no or too little organic peroxide was added, the molded product was deformed or contained coarse open cells, and a sufficient expansion ratio could not be obtained.

The results are shown in Table 1. Further, its properties are shown in Table 2. Table 1 Table 2

Claims (1)

[Claims] 1 A long chain formed from 20 to 80 parts by weight of short chain polyester units, of which 50 mol% or more consists of polybutylene terephthalate units, poly(alkylene oxide) glycol with a number average molecular weight of 500 to 6,000, and dicarboxylic acid with a molecular weight of 350 or less. A blowing agent is added to a block polyetherester copolymerized with a proportion of 80 to 20 parts by weight of polyester units and has a melting point of 100 to 220°C, and the block polyetherester has a lower decomposition temperature than the blowing agent and is crosslinked to the block polyetherester. By blending an organic peroxide that produces a A method for producing a polyester elastomer foam, the method comprising expanding a polyester elastomer foam by decomposing and gasifying an agent.