JP2000072914A - Vinyl chloride polymer/polyurethane thermoplastic elastomer foam and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a foam which is flexible, is excellent in recovery and dimensional stability, and is capable of being re-molten or re-dissolved by selecting a recyclable foam having a specified expansion ratio. SOLUTION: This foam is a recyclable vinyl chloride polymer/polyurethane thermoplastic elastomer foam having an expansion ratio of at least 3. The elastomer can be produced by subjecting to a urethanization reaction a vinyl chloride polymer having a degree of polymerization of, desirably, 1,000-4,000, a polymer polyol having a number-average molecular weight of, desirably, 500-8,000, an isocyanate compound having at least three NCO groups, a plasticizer, and a urethanization catalyst by melt blending under shear. The foam can be produced by kneading the elastomer and a chemical blowing agent, packing the obtained composition into a mold, pressurizing the composition in the mold to melt it under heating to decompose that chemical blowing agent, cooling the mold under pressure, releasing the pressure from the mold, and opening the mold to foam the molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl chloride polymer-polyurethane (hereinafter, referred to as PVC-PU) which has a high expansion ratio, is flexible, has excellent recoverability and dimensional stability, and is recyclable. The present invention relates to a thermoplastic elastomer foam and a method for producing the same.

[0002]

2. Description of the Related Art Hitherto, polystyrene foams, polyethylene foams and the like are generally known as resin foams. As a flexible resin foam, a soft vinyl chloride foam is known. As foams that are flexible and have excellent recoverability, crosslinked polyurethane foams, crosslinked polyethylene foams, crosslinked rubber foams, and the like are known and generally used.

[0003]

However, the resin foam made of a resin such as polystyrene or polyethylene as described above is recycled because the foam can be melted or dissolved even after the foam is formed. Is possible. However, such a resin foam has a problem that it is hard and inferior in flexibility and is inferior in recoverability.

[0004] A flexible resin foam made of soft vinyl chloride or the like has a problem that its recoverability is inferior. In addition, a large amount of plastic is added to a powdery paste vinyl chloride resin in order to provide flexibility. It was necessary to adopt a special molding method in which foaming was carried out after adding the agent to form a plastisol, which was inferior in versatility.

Further, crosslinked polyurethane foams, crosslinked rubber foams, crosslinked polyethylene foams and the like produced by crosslinking and foaming cannot be re-melted or redissolved because of the cross-linking. It is difficult and causes an increase in industrial waste.

It is possible to re-melt or re-melt,
Thermoplastic elastomers are known as recyclable elastic bodies, but thermoplastic elastomers generally have a low melt viscosity at the time of melting, and at present it is not possible to obtain a foam having a high expansion ratio as it is. . Then, in order to obtain a foam having a high expansion ratio with a thermoplastic elastomer, it was necessary to carry out crosslinking while sacrificing recyclability. Furthermore, a general styrene-based thermoplastic elastomer as a thermoplastic elastomer has a problem that dimensional stability when subjected to molding processing is inferior.

Accordingly, an object of the present invention is to provide a recyclable PVC-PU thermoplastic elastomer foam which has an unprecedented high expansion ratio, is flexible, has excellent recoverability and dimensional stability, and is capable of providing a method for producing the same. It is assumed that.

[0008]

The present inventors have conducted intensive studies in view of the above-mentioned situation, and as a result, a thermoplastic elastomer foam comprising a specific thermoplastic elastomer having a specific expansion ratio has solved the above-mentioned problems. Find out what you can do,
The present invention has been completed.

That is, the present invention relates to a PVC-PU thermoplastic elastomer foam characterized in that it is recyclable with an expansion ratio of 3 times or more, and to a method for producing the same.

Hereinafter, the present invention will be described in detail.

The PVC-PU thermoplastic elastomer constituting the PVC-PU thermoplastic elastomer foam of the present invention is an elastic material that can be re-melted or re-dissolved.

As the PVC-PU thermoplastic elastomer used in the present invention, any one can be used as long as it belongs to the PVC-PU thermoplastic elastomer, and examples thereof include a vinyl chloride polymer (hereinafter, referred to as PVC) and polyurethane. (Hereinafter, referred to as PU), and a composition comprising a plasticizer. Among them, a foam having particularly excellent flexibility can be used, and thus PVC, a polymer polyol,
PVC- obtained by subjecting an isocyanate compound having three or more isocyanate groups, a plasticizer and a urethanation reaction catalyst to a urethane reaction while heating and mixing under shearing force.
Preferably it is a PU thermoplastic elastomer.

[0013] The PVC herein refers to a vinyl chloride-containing polymer, a vinyl chloride homopolymer, a chlorinated vinyl chloride polymer, a monomer copolymerizable with a vinyl chloride monomer and a vinyl chloride monomer. And vinyl chloride copolymers obtained by random copolymerization, graft copolymerization or block copolymerization with one or more of these, or mixtures of two or more of these polymers.

The monomer copolymerizable with the vinyl chloride monomer includes, for example, ethylene, propylene, butene, pentene-1, butadiene, styrene, α-methylstyrene, acrylonitrile, vinylidene chloride, vinylidene cyanide; Alkyl vinyl ethers such as methyl vinyl ether; carboxylic acid vinyl esters such as vinyl acetate; aryl ethers such as methoxystyrene; dialkyl maleic acids such as dimethyl maleic acid; fumaric acid esters such as dimethyl fumarate; N-vinylpyrrolidone And vinyl pyridines and vinyl silanes; alkyl acrylates such as butyl acrylate; alkyl methacrylates such as methyl methacrylate.

The degree of polymerization of PVC is not particularly limited, and any one can be used. However, a PVC-PU thermoplastic elastomer foam having excellent flexibility and expandability can be obtained. used.

Further, PVC-P which is preferably used for a PVC-PU thermoplastic elastomer foam of the present invention described below.
When a polymer polyol and a plasticizer are impregnated with PVC in the production of a U thermoplastic elastomer, the PVC is preferably obtained by a suspension polymerization method.

The PU herein is preferably a crosslinkable polyurethane, and any PU may be used as long as it belongs to the category. Among them, a polymer polyol and an isocyanate compound having three or more isocyanate groups may be used. It is preferably a polyurethane having a network structure formed by the reaction.

Here, the polymer polyol has two or more hydroxyl groups. Examples thereof include polyester polyol, polyether polyol, polycarbonate polyol, vinyl polyol, diene polyol, castor oil polyol, and silicone polyol. , A polyolefin-based polyol or a copolymer thereof, and one or more of these are used.

The molecular weight of the polymer polyol is not particularly limited, and any one can be used. However, PV which is easy to handle, low in hardness and excellent in flexibility is used.
The number average molecular weight is preferably 500 or more and 8000 or less in order to obtain a C-PU thermoplastic elastomer foam.

The polyester polyol is obtained, for example, by subjecting a dicarboxylic acid and a short-chain polyol to condensation polymerization. At this time, as the dicarboxylic acid component, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid, phthalic acid, isophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, fumaric acid, itaconic acid And the like, and one or more of these are used. On the other hand, as the short-chain polyol component, aliphatic, alicyclic, aromatic, substituted aliphatic or heterocyclic dihydroxy compounds, trihydroxy compounds, tetrahydroxy compounds and the like, for example, 1,
2-ethanediol, 1,3-propanediol, 1,
4-butanediol, butenediol, 3-methyl-
1,5-pentanediol, 1,6-hexanediol, 1,10-decamethylenediol, 2,5-dimethyl-2,5-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanedimethanol, -Methyl-1,8-octanediol,
1,9-nonanediol, bis (β-hydroxyethoxy) benzene, p-xylenediol, dihydroxyethyltetrahydrophthalate, trimethylolpropane, glycerin, 2-methylpropane-1,2,3-triol, 1,2, 6-hexanetriol and the like, and one or more of these are used.

As another method for obtaining a polyester-based polyol, β-propiolactone, bivalolactone, δ-
Valerolactone, β-methyl-δ-valerolactone, ε
One or more lactone compounds such as caprolactone, methyl-ε-caprolactone, dimethyl-ε-caprolactone, trimethyl-ε-caprolactone, or one or more hydroxy compounds selected from the above short-chain polyol components; It is also possible to use a method of reacting with the above.

The polyether polyols include polytetramethylene glycol, polyethylene glycol,
Examples thereof include polypropylene glycol and polyoxypropylene glycol, and one or more of these are used.

As the polycarbonate-based polyol,
One obtained by transesterification from one or more hydroxy compounds selected from the above short-chain polyols and diallyl carbonate, dialkyl carbonate or ethylene carbonate is used. For example, poly (1,6-hexamethylene carbonate) is used. ), Poly (2,2'-bis (4-hydroxyhexyl) propane carbonate) and the like are industrially produced. As another method for obtaining a polycarbonate polyol, a so-called phosgene method can be used.

In addition, vinyl polyols such as acrylic polyols obtained by copolymerization of acrylic monomers having hydroxy groups such as β-hydroxyethyl acrylate and β-hydroxyethyl methacrylate and acrylic acid esters, and poly (1 , 4-butadiene) and poly (1,2-butadiene), castor oil-based polyols such as polypropylene glycol ricinoleate, silicone-based polyols, polyolefin-based polyols, and the like.

The isocyanate compound having three or more isocyanate groups includes, for example, isocyanurate-modified diisocyanate, 1,6,11-undecane triisocyanate, lysine ester triisocyanate,
Examples include triisocyanates such as isocyanatemethyl-1,8-octamethyldiisocyanate or polyfunctional isocyanates such as burette-modified, allophanate-modified, adduct, and polyphenylmethane polyisocyanate of diisocyanate. More than seeds are used. Examples of the diisocyanate include 2,4- or 2,6-tolylene diisocyanate, m- or p-phenylene diisocyanate, 1-chlorophenylene-2,4-diisocyanate, 1,5-naphthalene diisocyanate, and methylene bisphenylene-isocyanate. 4,4'-diisocyanate, m- or p-xylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, and the like.

The above-mentioned diisocyanates can be used in combination with the PVC-PU thermoplastic elastomer constituting the PVC-PU thermoplastic elastomer foam of the present invention. However, in this case, the molar number of isocyanate groups of the isocyanate compound having three or more isocyanate groups with respect to the molar number of isocyanate groups of all the isocyanate compounds is preferably 0.25 or more.

The molar ratio (NCO / OH molar ratio) of the isocyanate group in the isocyanate compound to the hydroxyl group of the polymer polyol has a good expansion ratio,
When a diol is used as the polymer polyol since a PVC-PU thermoplastic elastomer foam having excellent flexibility is obtained, the diol is preferably from 0.3 to 1.3, particularly preferably from 0.5 to 1.1. preferable.

When producing PU, it is preferable to carry out the PU production reaction in the presence of a urethanization reaction catalyst. The urethanization reaction catalyst is not particularly limited and any known catalyst can be used. For example, amine catalysts such as triethylamine, triethylenediamine, and N-methylmorpholine; tetramethyltin, tetraoctyltin, dimethyldioctyltin, and triethyltin chloride And tin-based catalysts such as dibutyltin diacetate and dibutyltin dilaurate. One or more of these can be used, and dibutyltin dilaurate is preferably used. The amount of the catalyst used depends on the activity of the catalyst used, but the amount necessary for completing the urethane reaction is good. Taking dibutyltin dilaurate as an example, the amount is preferably 1 ppm or more and 10000 ppm or less based on the total amount of PVC, polymer polyol, isocyanate compound and plasticizer.

The PVC-PU thermoplastic elastomer constituting the PVC-PU thermoplastic elastomer foam of the present invention is obtained by shearing, for example, PVC, a polymer polyol, an isocyanate compound having three or more isocyanate groups, a plasticizer, and a urethanization reaction catalyst. Under force, when using a PVC-PU thermoplastic elastomer obtained by urethane reaction while heating and melting and mixing, the amount of PU in the PVC-PU thermoplastic elastomer, that is, the total blended amount of the polymer polyol and the isocyanate compound is flexible, From the viewpoint of obtaining a PVC-PU thermoplastic elastomer foam having an excellent expansion ratio, the amount is preferably 30 parts by weight or more and 600 parts by weight or less based on 100 parts by weight of PVC.

Examples of the plasticizer include di-n-butyl phthalate, di-2-ethylhexyl phthalate (hereinafter referred to as DOP), di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate, Phthalic acid-based plasticizers such as diisooctyl phthalate, octyldecyl phthalate, butylbenzyl phthalate, di-methylcyclohexyl phthalate, di-cyclohexyl phthalate, and di-2-ethylhexyl isophthalate; di-2-ethylhexyl adipate; Di-n-decyl adipate, diisodecyl adipate, dibutyl sebacate, di-2-sebacate
Aliphatic ester plasticizers such as ethylhexyl; trimellitic acid plasticizers such as trioctyl trimellitate and tridecyl trimellitate; tributyl phosphate, tri-2-ethylhexyl phosphate, 2-ethylhexyl diphenyl phosphate, tricresyl phosphate And plasticizers such as trixylenyl phosphate; epoxy plasticizers such as epoxy soybean oil; and polyester polymer plasticizers. One or more of these can be used.

In this case, the amount of the plasticizer to be blended depends on the PV of the present invention.
C-PU thermoplastic elastomer foam has excellent flexibility,
PVC10
It is preferably from 10 parts by weight to 300 parts by weight with respect to 0 parts by weight.

The PVC-PU thermoplastic elastomer constituting the PVC-PU thermoplastic elastomer foam of the present invention is prepared by shearing, for example, PVC, a polymer polyol, an isocyanate compound having three or more isocyanate groups, a plasticizer, and a urethanization reaction catalyst. When producing a PVC-PU thermoplastic elastomer to use a PVC-PU thermoplastic elastomer obtained by performing a urethane reaction while heating and mixing under heat, PVC, a polymer polyol, an isocyanate compound having three or more isocyanate groups, For example, a plasticizer and a urethanization reaction catalyst may be mixed with a Banbury mixer (manufactured by Farrell), a pressure kneader (manufactured by Moriyama Seisakusho), an internal mixer (manufactured by Kurimoto Iron Works), an intensive mixer (manufactured by Nippon Roll Manufacturing Co., Ltd.)
PU) can be produced by heating and melting and mixing under shearing force using a kneading and molding machine used for processing plastics or rubber, such as a mechanical press kneading machine, roll molding machine, extrusion molding machine, etc. Preferably, the temperature for the heat-melt mixing at that time is 90 to 220 ° C, preferably 100 to 15 ° C.
0 ° C.

The PVC-PU thermoplastic elastomer foam of the present invention is a remeltable or re-dissolvable foam.

The PVC-PU thermoplastic elastomer foam of the present invention has an expansion ratio of 3 times or more. When the expansion ratio is less than 3 times, the obtained PVC-
PU thermoplastic elastomer foams are stiff and less flexible.

The expansion ratio as referred to in the present invention is obtained by the following general formula (1).
It is an index indicating how many times the PU thermoplastic elastomer is swollen.

Expansion ratio = (density of raw material PVC-PU thermoplastic elastomer before foaming) / (apparent density of PVC-PU thermoplastic elastomer foam after foaming) (1) Also, the term “recyclable” in the present invention means , Means that the PVC-PU thermoplastic elastomer foam can be re-melted or redissolved.

The method for producing the PVC-PU thermoplastic elastomer foam of the present invention is as follows. The PVC-PU thermoplastic elastomer of the present invention is a recyclable PVC-PU thermoplastic elastomer foam having an expansion ratio of 3 times or more. Any production method may be used as long as a foam can be obtained. Particularly, PV with high production efficiency and high expansion ratio is used.
Since a C-PU thermoplastic elastomer foam can be obtained, it is preferable that the PVC-PU thermoplastic elastomer be produced through at least the following three steps (a) to (c) when foaming the thermoplastic elastomer.

(A) A step of filling a foaming PVC-PU thermoplastic elastomer composition containing a PVC-PU thermoplastic elastomer and a chemical foaming agent into a molding die.

(B) Next, a step of heating the inside of the molding die under pressure to heat and melt the foamable PVC-PU thermoplastic elastomer composition to decompose the chemical foaming agent.

(C) Further, after the molding die is cooled under pressure, the inside of the molding die is depressurized, and the molding die is opened and foamed.

Here, as the chemical foaming agent, a chemical foaming agent generally used in producing a foam can be used. For example, azodicarbonamide (hereinafter ADCA)
Say ), Barium azodicarboxylate, azobisisobutyronitrile, azo compounds such as diazoaminobenzene, nitroso compounds such as n, n'-dinitrosopentamethylenetetramine, and 4,4'-oxybis (benzenesulfonylhydrazide) ( Hereinafter, referred to as OBSH.), Hydrazine derivatives such as hydrazodicarbonamide, paratoluenesulfonyl hydrazide, organic thermal decomposition foaming agents such as semicarbazide compounds, azide compounds and triazole compounds; organic reaction foaming agents such as isocyanate compounds. An inorganic pyrolytic foaming agent such as bicarbonate, carbonate, nitrite, hydride, etc .; an inorganic reactive foaming agent such as a combination of sodium bicarbonate and acid, zinc powder and acid, and a cellulosic foaming agent. Can be

Further, a foaming aid may be added to the foamable PVC-PU thermoplastic elastomer composition, if necessary. Examples of such foaming aids include organic acid-based foaming aids such as stearic acid, lauric acid, and salicylic acid; fatty acid metal salt-based foaming aids such as zinc stearate, calcium stearate, and barium stearate; and urea-based foaming aids. Agents, metal oxides such as zinc oxide and magnesium oxide; diethylene glycol, glycerin and the like.

The foamable PVC-PU thermoplastic elastomer composition at this time is excellent in handleability when producing the PVC-PU thermoplastic elastomer foam of the present invention, and the obtained PVC-PU thermoplastic elastomer foam is excellent. Since the body is particularly flexible and excellent in expansion ratio, PVC-P
Expandable PVC-PU comprising 0.1 to 30 parts by weight of a chemical blowing agent with respect to 100 parts by weight of U thermoplastic elastomer
It is preferable to treat it as a thermoplastic elastomer composition.

Such a foamable PVC-PU thermoplastic elastomer composition can be obtained by dry blending and / or melt blending a PVC-PU thermoplastic elastomer and a chemical foaming agent. At this time, if dry blending is performed, for example, a mixer such as a ribbon blender with a jacket, a Henschel mixer (manufactured by Mitsui Miike Seisakusho), a super mixer (manufactured by Kawada Seisakusho), a tumbler brabender, or a V-brabender may be used. . If melt blending is performed, for example, a Banbury mixer (manufactured by Farrell), a pressure kneader (manufactured by Moriyama Seisakusho), an internal mixer (manufactured by Kurimoto Iron Works), an intensive mixer (manufactured by Nippon Roll Manufacturing Co., Ltd.) Kneading and molding machines used for processing plastics or rubber, such as a mechanical pressurizing kneader, roll forming machine, and extruder. The processing temperature at the time of performing the melt blending is equal to or lower than the decomposition temperature of the chemical foaming agent to be used, preferably 100 to 150 ° C, more preferably 100 to 130 ° C. Here, foamable PVC-PU
The thermoplastic elastomer composition is preferably melt-blended and used since the blowing agent is less scattered during production.

Further, the fact that general PVC-PU thermoplastic elastomers are sold in pellets,
In the above-mentioned step (a), it is preferable that the foamable PVC-PU thermoplastic elastomer composition is filled in a molding die in a solid state in the step (a) because of excellent handleability during the production of the PU thermoplastic elastomer foam.

In the above step (a), foamable PVC
-The filling rate when the PU thermoplastic elastomer composition is filled into a molding die is such that the foam cells of the PVC-PU thermoplastic elastomer foam of the present invention are uniform, and the foaming agent has excellent decomposition efficiency during molding processing, It is preferably 65% or more and 99% or less from the viewpoint that the foaming gas can be efficiently held.

In the step (b), the pressure of the molding die when heating under pressure is higher than that of the molding die by P.
VC-PU thermoplastic elastomer without leakage
In order to obtain a PVC-PU thermoplastic elastomer foam having a uniform foam cell, the foaming cell is preferably set to 20 to 150 kg / cm ^2, and the heating temperature is equal to or higher than the decomposition temperature of the chemical foaming agent, and is preferably 150 to 180 ° C. .

Further, in the step (c), (b)
When the molding die is cooled under pressure in the process, the foamed cell structure of the obtained PVC-PU thermoplastic elastomer foam is maintained and the productivity is excellent.
It is preferred to cool to 0-90 ° C.

Further, the PVC-PU thermoplastic elastomer foam of the present invention is preferably subjected to a heat treatment at 60 to 180 ° C. after forming the foam in order to make the foam more flexible and excellent in dimensional stability.

The PVC-PU thermoplastic elastomer foam of the present invention can be used for conveying conveyor belts such as conveyor belts, resin conveyor belts, steeply inclined conveyors, cylindrical conveyor belts and the like; power transmission belts such as V-belts, toothed belts and the like. Hose such as braided hose, cloth wound hose, high pressure hose, suction hose, duct hose, spray hose, water supply / drainage hose, pressure-resistant reinforcement hose, antistatic hose, etc .; automotive, railway, industrial machinery, construction civil engineering Industrial rolls such as anti-vibration materials, fenders, printing rolls, papermaking rolls, spinning rolls, steelmaking rolls, dyeing fiber rolls, etc .; office machine rolls, OA equipment rolls, etc.
Rolls for various equipment such as rolls for automation equipment; Rolls for agricultural machines such as milling machines; Lining of various materials including metals; Sheets such as decorative sheets, antistatic sheets, roofing sheets, etc .; Cell phone cases , Packing for remote control cases of electric appliances, etc .; sealing material, waterproofing material, oil seal, mechanical seal, molded packing,
Seals for movement such as gland packing; Seals for fixing O-rings, gaskets, etc .; Seals for capacitors, sponge products, stoppers, catheters, droppers, syringe gaskets, masks, sacks, gloves, condoms, water pillows, bedding,
Futons, tatami mats, cushions, baby nipples, cap containers,
Rainwear, airbags, diaphragms, rubber dams, gas envelopes, oil fences, flexible containers, golf balls, soccer balls and other balls, sports floors, cushioning rubber for fences, chains, paving blocks, automotive boots, weather Strip, building gasket, seismic isolation rubber, handrail, non-slip, airtight,
Spacers, laminated glass, waterproof boards, elastic joints, thread rubber, rubber cords, handrails, plastic magnets, rubber magnets, electric wires, cords, casters, bearings, couplings, cushions, bushes, boots, grommets, insulators , Stopper, wiper blade, joint, damping rubber, rubber switch, socket,
Dolls, toys, masks, shoes, rubber feet, tubes, packing for electrical appliances, industrial parts, grips for golf clubs, tennis rackets, ski poles, etc., sealants, seats, electrical components, electronic components, semiconductive films, electrification Films / sheets such as prevention films, pharmaceutical films, tires,
Precision equipment, vibration absorbers for precision processing equipment, sports equipment,
It can be used for daily goods, seats, etc.

[0051]

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Synthesis Example 1 100 parts by weight of an ethylene-vinyl chloride copolymer (manufactured by Taiyo Vinyl Co., Ltd., trade name: TE-2800) obtained by a suspension polymerization method in a Henschel mixer having an internal volume of 20 liters, magnesium stearate (Hereinafter referred to as Mg stearate) 3 parts by weight, microwax (Nippon Seiro Co., Ltd.)
3 parts by weight, trade name: LUVAX 2191), 2 parts by weight of barium stearate as a stabilizer, perchloric acid-treated hydrotalcite (manufactured by Nissan Ferro-Organic Chemical Co., Ltd., trade name B)
P-331) 1.5 parts by weight were charged and stirred at a rotation speed of 950 rpm for 1 minute.

Separately, a polymer polyol (Nipporan 406, manufactured by Nippon Polyurethane Co., Ltd.)
7, number average molecular weight 2000) 50 parts by weight, DOP100
A mixture of 0.15 parts by weight of dibutyltin dilaurate (a urethanization reaction catalyst) for 1 minute was prepared.
This is added to the above Henschel mixer and the temperature of the mixture becomes 1
The mixture was stirred and mixed until the temperature reached 20 ° C. Contents are 4 in total
000 g. The mixture became a powdery mixture that could easily flow.

The obtained powdery mixture (259.65 parts by weight) was charged into a Banbury mixer having a capacity of 1.7 liters and a set temperature of 110 ° C., and stirred at a constant rotation speed. Separately, 37 parts by weight of a modified isocyanurate of hexamethylene diisocyanate (trade name: Coronate HX, manufactured by Nippon Polyurethane Co., Ltd.), and a polymer polyol heated to 80 ° C. (trade name: Nipporan, manufactured by Nippon Polyurethane Co., Ltd.) 4067, 263 parts by weight (number-average molecular weight: 2,000) (NCO / OH molar ratio = 0.60) and mixed for 1 minute were prepared and poured from the Banbury mixer inlet. The content was 1540 g in total. Under shear force
The mixture was heated and melted and discharged when the temperature of the melted mixture reached 175 ° C. to obtain a PVC-PU thermoplastic elastomer.

When the density of the obtained PVC-PU thermoplastic elastomer was measured according to JIS K 7112, it was 1.11 g / cm ³ .

Example 1 An ADCA / OBSH-based blowing agent (trade name: Spancell DS # 2, manufactured by Eiwa Chemical Co., Ltd.) was added to 100 parts by weight of the PVC-PU thermoplastic elastomer obtained in Synthesis Example 1.
5) 5 parts by weight were blended and kneaded using an 8-inch roll kneader having a surface temperature set to 130 ° C. to prepare a sheet-like foamable PVC-PU thermoplastic elastomer composition.

The sheet of the foamable PVC-PU thermoplastic elastomer composition thus obtained was cut, and the upper surface was 88 mm × 88 mm.
A molding machine filled with a filling rate of 86% in a molding die having the shape of a truncated square pyramid having a height of 13 mm, a bottom surface of 61 mm × 61 mm and a height of 13 mm, and a molding die set at a surface temperature of 170 ° C.
43Kg / c using Lab Press (Toyo Seiki Seisakusho)
Heated under m ² pressure for 10 minutes. Thereafter, the temperature was cooled to 35 ° C., the pressure in the pressure molding machine was released, and the molding die was opened. Thus, a PVC-PU thermoplastic elastomer foam was obtained.

When the apparent density of the obtained PVC-PU thermoplastic elastomer foam was measured in accordance with JIS K6767, it was 0.25 g / cm ³ . The expansion ratio of the obtained PVC-PU thermoplastic elastomer foam was 4.4.

The durometer E hardness test of the PVC-PU thermoplastic elastomer foam obtained in accordance with JIS K 6253 was 21.

Further, when the obtained PVC-PU thermoplastic elastomer foam was subjected to a heat treatment in an oven at a set temperature of 80 ° C. for 1 hour, the durometer E hardness became 11. In addition, 90 hours after taking out from oven
After the marking was performed, the length of the marking was measured and the shrinkage percentage was calculated to be 2% after 5 days.

When the obtained PVC-PU thermoplastic elastomer foam was kneaded with an 8-inch roll kneader set at a surface temperature of 150 ° C., kneading was possible.
The U thermoplastic elastomer foam was recyclable.

The obtained PVC-PU thermoplastic elastomer foam has a high expansion ratio, is flexible, has dimensional stability,
It was excellent in recyclability.

Example 2 An ADCA / OBSH-based blowing agent (trade name: Spancell DS # 2, manufactured by Eiwa Chemical Co., Ltd.) was added to 100 parts by weight of the PVC-PU thermoplastic elastomer obtained in Synthesis Example 1.
5) By mixing 10 parts by weight and kneading using an 8-inch roll kneader having a surface temperature set to 130 ° C.,
A sheet-like foamable PVC-PU thermoplastic elastomer composition was prepared.

The sheet of the foamable PVC-PU thermoplastic elastomer composition thus obtained was cut, and the upper surface was 88 mm × 88 mm.
A molding machine filled with a filling rate of 86% in a molding die having the shape of a truncated square pyramid having a height of 13 mm, a bottom surface of 61 mm × 61 mm and a height of 13 mm, and a molding die set at a surface temperature of 170 ° C.
43Kg / c using Lab Press (Toyo Seiki Seisakusho)
Heated under m ² pressure for 10 minutes. Thereafter, the temperature was cooled to 35 ° C., the pressure in the pressure molding machine was released, and the molding die was opened. Thus, a PVC-PU thermoplastic elastomer foam was obtained.

When the apparent density of the obtained PVC-PU thermoplastic elastomer foam was measured in accordance with JIS K6767, it was 0.095 g / cm ³ . The expansion ratio of the obtained PVC-PU thermoplastic elastomer foam was 11.7.

A durometer E hardness test of the PVC-PU thermoplastic elastomer foam obtained in accordance with JIS K 6253 was 12.

Further, when the obtained PVC-PU thermoplastic elastomer foam was subjected to a heat treatment in an oven at a set temperature of 80 ° C. for 1 hour, the durometer E hardness became 7.

Also, one hour after taking out of the oven, a stamp of 100 mm in length was formed, and after 5 days, the length of the stamp was measured and the shrinkage was calculated to be 3%.

When the obtained PVC-PU thermoplastic elastomer foam was kneaded with an 8-inch roll kneader set at a surface temperature of 150 ° C., kneading was possible.
The U thermoplastic elastomer foam was recyclable.

The obtained PVC-PU thermoplastic elastomer foam has a high expansion ratio, is flexible, has dimensional stability,
It was excellent in recyclability.

Comparative Example 1 An ADCA / OBSH-based blowing agent (trade name: Spancell DS # 2, manufactured by Eiwa Chemical Co., Ltd.) was added to 100 parts by weight of the PVC-PU thermoplastic elastomer obtained in Synthesis Example 1.
5) A 20 mm single screw extruder (2% by weight)
Toyo Seiki Seisakusho Co., Ltd., trade name Labo Plast Mill)
Under the conditions of a cylinder temperature of 120 ° C. and a die temperature of 130 ° C., pellets of an extrudable foamable PVC-PU thermoplastic elastomer composition were obtained.

The obtained foamable PVC-PU thermoplastic elastomer composition pellets were subjected to a cylinder temperature of 170 ° C.
Using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., Model IS50EP) set at a nozzle temperature of 180 ° C., 70 × 70 ×
It was molded into a 3 (mm) foam molded article.

The apparent density of the obtained foamed PVC-PU thermoplastic elastomer was measured in accordance with JIS K 7112 and found to be 0.74 g / cm ³ . The expansion ratio of the obtained PVC-PU thermoplastic elastomer foam was 1.5.

The durometer E hardness test of the PVC-PU thermoplastic elastomer foam obtained according to JIS K 6253 was 31.

The obtained PVC-PU thermoplastic elastomer foam had a low expansion ratio and was inferior in flexibility.

Comparative Example 2 An ADCA / OBSH-based blowing agent (trade name: Spancell DS # 2, manufactured by Eiwa Chemical Co., Ltd.) was added to 100 parts by weight of the PVC-PU thermoplastic elastomer obtained in Synthesis Example 1.
5) By mixing 10 parts by weight and kneading using an 8-inch roll kneader having a surface temperature set to 130 ° C.,
A sheet-like foamable PVC-PU thermoplastic elastomer composition was prepared.

The obtained foamable PVC-PU thermoplastic elastomer composition sheet was cut to obtain pellets.

Using the pellets of the foamable PVC-PU thermoplastic elastomer composition obtained, a cylinder temperature of 170 was used.
70 × 70 using an injection molding machine (Model IS50EP, manufactured by Toshiba Machine Co., Ltd.) set at 180 ° C. and a nozzle temperature of 180 ° C.
An attempt was made to form a foam of × 3 (mm), but foaming in the cylinder was severe and could not be performed.

Comparative Example 3 100 parts by weight of ethylene-propylene-diene rubber, 0.5 part by weight of dicumyl peroxide, an OBSH-based foaming agent (manufactured by Eiwa Kasei Kogyo Co., Ltd., trade name: Neoserbon N # 10)
00S) 8 parts by weight were blended and kneaded using an 8-inch roll kneader set at a surface temperature of 130 ° C. to obtain a sheet-like foamable resin composition.

The obtained sheet-shaped foamable resin composition was
An ethylene-propylene-diene rubber cross-linked foam was obtained by normal-pressure cross-linking foam molding in an oven set at 70 ° C.

The expansion ratio of the obtained crosslinked foam of ethylene-propylene-diene rubber was 10 times.

An attempt was made to knead the obtained crosslinked foam of ethylene-propylene-diene rubber with an 8-inch roll kneader set at a surface temperature of 150 ° C., but the kneading could not be carried out and the recyclability was poor. Was.

Comparative Example 4 Hand sewing machine (trade name: NP-7, manufactured by Neurong Co., Ltd.)
When the specific gravity of the polystyrene foam used as the packaging material of B) was measured in accordance with JIS K 6767, it was 0.03 g / cm ³ . The expansion ratio of the obtained polystyrene foam was 33.

The durometer E hardness test of the PVC-PU thermoplastic elastomer foam obtained according to JIS K 6253 was 55.

The polystyrene foam had a very high expansion ratio but was hard.

Comparative Example 5 Styrene-based thermoplastic elastomer (manufactured by Mitsubishi Chemical Corporation)
Trade name Lavalon T320C; specific gravity 0.89 g / cm ³ )
ADCA / OBSH-based foaming agent (Spancel DS # 25, manufactured by Eiwa Chemical Industry Co., Ltd.) per 100 parts by weight
A sheet-shaped expandable styrene-based thermoplastic elastomer composition was prepared by mixing the parts by weight and kneading using an 8-inch roll kneader having a surface temperature set to 130 ° C.

The sheet of the obtained expandable styrene-based thermoplastic elastomer composition was cut, and the upper surface was 88 mm × 88 m
m, bottom surface 61 mm x 61 mm, height 13 mm Filled into a molding die having a shape of a truncated pyramid at a filling rate of 86%, and the molding die was set at a surface temperature of 170 ° C (Press Co., Ltd.) 43Kg / cm using a laboratory press manufactured by Toyo Seiki Seisakusho
Heated under pressure of ² for 10 minutes. Thereafter, the temperature was cooled to 35 ° C., and after the pressure in the pressure molding machine was released, the molding die was opened, whereby a styrene-based thermoplastic elastomer foam was obtained.

The apparent density of the obtained styrene-based thermoplastic elastomer foam was measured according to JIS K6767 and found to be 0.24 g / cm ³ . The expansion ratio of the obtained styrene-based thermoplastic elastomer foam was 3.7.

The durometer E hardness test of the styrene thermoplastic elastomer foam obtained in accordance with JIS K 6253 was 16.

Further, when the obtained styrene-based thermoplastic elastomer foam was heat-treated in an oven at a set temperature of 80 ° C., the durometer E hardness was 12.

Also, one hour after taking out of the oven, a stamp of 80 mm in length was formed, and after 5 days, the length of the stamp was measured and the shrinkage was calculated to be 32%.

The obtained styrene-based thermoplastic elastomer foam had poor dimensional stability.

Comparative Example 6 An ADCA / OBSH-based blowing agent (trade name: Spancell DS # 2, manufactured by Eiwa Chemical Co., Ltd.) was added to 100 parts by weight of the PVC-PU thermoplastic elastomer obtained in Synthesis Example 1.
5) 5 parts by weight were blended and kneaded using an 8-inch roll kneader having a surface temperature set to 130 ° C. to prepare a sheet-like foamable PVC-PU thermoplastic elastomer composition.

The sheet of the foamed PVC-PU thermoplastic elastomer composition thus obtained was cut, and the upper surface was 88 mm × 88 mm.
A molding machine filled with a filling rate of 86% in a molding die having the shape of a truncated square pyramid having a height of 13 mm, a bottom surface of 61 mm × 61 mm and a height of 13 mm, and a molding die set at a surface temperature of 170 ° C.
43Kg / c using Lab Press (Toyo Seiki Seisakusho)
Heated under m ² pressure for 10 minutes. Thereafter, the pressure was released from the pressure molding machine without cooling, and then the molding die was opened. As a result, blowing occurred and a foam was not obtained.

[0095]

The foam of the present invention is a recyclable PVC-PU thermoplastic elastomer foam having excellent flexibility, recoverability and dimensional stability, and its industrial value is extremely high.

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Claims (4)

[Claims] 1. A foamed polyvinyl chloride-polyurethane thermoplastic elastomer foam having an expansion ratio of 3 times or more and being recyclable. 2. A vinyl chloride polymer-polyurethane thermoplastic elastomer comprising a vinyl chloride polymer, a polymer polyol, an isocyanate compound having three or more isocyanate groups, a plasticizer, and a urethanation catalyst under shearing force.
The foam according to claim 1, wherein the foam is a vinyl chloride polymer-polyurethane thermoplastic elastomer obtained by a urethane reaction while being heated and mixed. 3. The method according to claim 1, wherein the foam molding of the vinyl chloride polymer / polyurethane thermoplastic elastomer is performed through at least the following three steps (a) to (c). A method for producing a vinyl chloride polymer-polyurethane thermoplastic elastomer foam. (A) A step of filling a foaming vinyl chloride polymer-polyurethane thermoplastic elastomer composition comprising a vinyl chloride polymer-polyurethane thermoplastic elastomer and a chemical foaming agent into a molding die. (B) Next, a step of heating the inside of the molding die under pressure to heat and melt the foamable vinyl chloride polymer-polyurethane thermoplastic elastomer composition to decompose the chemical foaming agent. (C) A step of further cooling the molding die while applying pressure, and then depressurizing the interior of the molding die to open and foam the molding die. 4. The foamable vinyl chloride polymer-polyurethane thermoplastic elastomer composition comprising a vinyl chloride polymer-polyurethane thermoplastic elastomer and a chemical foaming agent in the step (a) according to claim 3. The method for producing a vinyl chloride polymer-polyurethane thermoplastic elastomer foam according to claim 3, wherein the foam is solid and filled in a molding die.