JP2008179812A - Method of producing millable urethane rubber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of producing a millable urethane rubber excellent in moldability and having good mechanical properties. <P>SOLUTION: The method of producing the millable urethan rubber comprises preparing a millable urethane resin (A) by reacting and hardening a liquid mixture of a polyol constituent (a) containing a polyol having at least one ethylenic unsaturated group in the molecular side chain and an isocyanate constituent (b) on the surface of or in the bag of a thermoplastic resin film (B) having a melting point of 60-110°C, adding a curing agent thereto, and melting and kneading without removing the (B), to harden the resultant mixture. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing millable urethane rubber. More specifically, the present invention relates to a method for producing a millable urethane rubber that does not cause a crosslinking reaction during the production of the millable urethane resin, and that is subsequently crosslinked and cured by adding a vulcanizing agent to the millable urethane resin.

Conventionally, a thermoplastic polyurethane resin can be produced by a bulk polymerization method carried out in the absence of a solvent. As the bulk polymerization method, (1) a batch method in which a mixture of a polyol component and an isocyanate component is poured into a mold and reacted. (2) An extrusion method in which a polyol component and an isocyanate component are continuously supplied to an extruder, mixed and reacted in the extruder and taken out in a rod shape is known (for example, see Patent Document 1).
On the other hand, a millable urethane resin is known as a polyurethane resin that can be crosslinked and molded with sulfur or peroxide like rubber. The millable urethane resin is a thermoplastic polyurethane resin into which an ethylenically unsaturated bond is introduced. After sulfur or peroxide is kneaded with this, it is thermally cured by an extruder or a press to obtain a millable urethane rubber molded product. . Since the molded article has good wear resistance and oil resistance, it is used for paper-conveying rolls and belts (see, for example, Patent Document 2) and industrial sheets.

Japanese Patent Laid-Open No. 11-181043 JP 2001-122976 A

However, when a millable urethane resin is produced using a thermoplastic polyurethane resin production method (bulk polymerization method), the batch method (1) can be used to apply a release agent to the casting mold and to remove the resulting millable urethane resin. There was a problem that it took time.
In addition, in the extrusion method (2), the reaction is carried out at a high temperature of 210 to 240 ° C. in order to suppress the cross-linking reaction that occurs due to the side reaction of the isocyanate. However, when a polyol component having an ethylenically unsaturated bond is reacted, There was a problem that a cross-linking reaction based on it occurred.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems. That is, the present invention relates to a thermoplastic resin film having a melting point of 60 to 110 ° C. using a mixture of a polyol component and an isocyanate component containing a polyol having at least one ethylenically unsaturated group in the molecular side chain. A vulcanizing agent is added to the millable urethane resin (A) which is reacted and cured on the surface of (B) or in a bag, and melted, kneaded and cured without removing (B). A method for producing millable urethane rubber; and a millable urethane rubber obtained by the production method.

The manufacturing method of the millable urethane rubber of the present invention and the millable urethane rubber obtained by the manufacturing method have the following effects.
(1) A crosslinking reaction based on an unsaturated bond does not occur during the production of a millable urethane resin.
(2) Excellent work efficiency when manufacturing millable urethane resin and millable urethane rubber.
(3) Millable urethane rubber is excellent in moldability and has good mechanical properties.

The polyol component (a) in the present invention includes a polyol (a1) having at least one ethylenically unsaturated group in the molecular side chain.
As (a1), (a11) unsaturated group-containing low molecular polyol [carbon number (hereinafter abbreviated as C) 4 to 20], (a12) alkylene oxide of the polyol (hereinafter abbreviated as AO) [and, if necessary, allyl glycidyl Ether (hereinafter abbreviated as AGE)] adducts, (a13) AGE (and optionally AO) adducts of compounds containing two or more active hydrogen atoms, and mixtures thereof.
Among (a1), (a12) and / or (a13) are preferable from the viewpoint of heat resistance of the millable urethane resin (A).
Examples of the ethylenically unsaturated group include an allyl group and / or a (meth) acryloyl group, and an allyl group is preferred from the viewpoint of water resistance.

  Examples of the unsaturated group-containing low molecular polyol (a11) include C6-20 aliphatic polyols such as glycerin (hereinafter abbreviated as GR) monoallyl ether, trimethylolpropane (hereinafter abbreviated as TMP) monoallyl ether, pentaerythritol ( (Hereinafter abbreviated as PE) monoallyl ether, PE diallyl ether, GR mono (meth) acrylate, TMP mono (meth) acrylate, and the like. GR- and TMP monoallyl ether are preferred from the viewpoint of water resistance.

  AO in the AO (and optionally AGE) adduct (a12) of polyol is C2-12, for example, ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-, 1,3- And 2,3-butylene oxide (hereinafter abbreviated as BO), tetrahydrofuran (THF), substituted AO [epoxidized product of C5-12 α-olefin, styrene oxide and epihalohydrin (such as epichlorohydrin and epibromohydrin), and the like. .

  The compound containing two or more active hydrogen atoms in the AGE (and optionally AO) adduct (a13) of a compound containing two or more active hydrogen atoms includes C2 or more and a number average molecular weight [hereinafter referred to as Mn and Abbreviation. The measurement is based on a gel permeation chromatography (GPC) method. The following (i) low molecular polyols, (ii) polyhydric phenols and (iii) low molecular amines, and their AO (above) adducts, etc., of 400 or less.

(I) Low molecular polyol C2-20 or more dihydric alcohols such as C2-12 aliphatic dihydric alcohols [(di) alkylene glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1
, 2-, 2,3-, 1,3- and 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and 3-methylpentanediol (hereinafter referred to as EG, DEG, PG, DPG, BD, respectively) HD, NPG and MPD), dodecanediol, etc.], C6-10 alicyclic dihydric alcohol [1,4-cyclohexanediol, cyclohexanedimethanol, etc.], C8-20 araliphatic dihydric alcohol [xyl Lenglycol, bis (hydroxyethyl) benzene, etc.]; trihydric to octahydric or higher polyhydric alcohols such as (cyclo) alkane polyols and their intramolecular or intermolecular dehydrates [GR, TMP, PE, sorbitol ( Hereinafter abbreviated as SO) and dipentaerythritol (hereinafter abbreviated as DPE), 1,2.
, 6-hexanetriol, erythritol, cyclohexanetriol, mannitol, xylitol, sorbitan, diGR and other polyGR, etc.], saccharides and their derivatives [eg sucrose, glucose, fructose, mannose, lactose, and glycosides (methylglucoside, etc.) ]etc.

(Ii) Polyhydric phenol C6-18 dihydric phenol such as monocyclic dihydric phenol (hydroquinone, catechol, resorcinol, urushiol, etc.), bisphenol (bisphenol A, -F, -C, -B, -AD) And -S, dihydroxybiphenyl, 4,4′-dihydroxydiphenyl-2,2-butane, etc.), and condensed polycyclic dihydric phenols [dihydroxynaphthalene (1,5-dihydroxynaphthalene, etc.), binaphthol, etc.]; and trivalent -8 or higher polyhydric phenols such as monocyclic polyphenols (pyrogallol, phloroglucinol, and mono- or dihydric phenols (phenol, cresol, xylenol, resorcinol, etc.) aldehydes or ketones (formaldehyde, glutar) Aldehyde, glio Saar, acetone) Teichijimigobutsu (phenol or cresol novolak resins, intermediates resol, polyphenols obtained by condensation reaction of phenol with glyoxal or glutaraldehyde, and polyphenols obtained by condensation reaction of resorcin and acetone) and the like.

(Iii) Low molecular amine Ammonia; C2-20 aliphatic mono- or polyamine [C2-20 alkanolamine (mono-, di- and triethanolamine, isopropanolamine, etc.), C1-20 alkylamine (n-butylamine) , Octylamine, etc.), C2-6 alkylenediamine (ethylenediamine, propylenediamine, hexamethylenediamine, etc.), C4-20 polyalkylene polyamine (alkylene group C having 6-6 dialkylenetriamine to hexaalkyleneheptamine, For example, diethylenetriamine and triethylenetetramine)]; C6-20 aromatic mono- or polyamines (aniline, phenylenediamine, tolylenediamine, xylylenediamine, diethyltoluenediamine, methylenedianiline) , Diphenyl ether diamine, etc.), C4-20 alicyclic mono- or polyamines (cyclohexylamine, isophoronediamine, cyclohexylenediamine, dicyclohexylmethanediamine, etc.), C4-20 heterocycle-containing amines (piperazine, aminoethylpiperazine, etc.), etc. .

  Mn of (a12) and (a13) is preferably 300 to 6,000, more preferably 500 to 5,000 from the viewpoint of heat resistance of the millable urethane resin (A) and reactivity with the isocyanate component (b). is there.

  The unsaturated group concentration of the polyol (a1) is preferably 1 × 10 −4 to 80 × 10 −4 equivalent / g, more preferably 2 × from the viewpoint of mechanical strength, rubber elasticity and flexibility of the millable urethane rubber described later. 10 <-4> to 60 * 10 <-4> equivalent / g.

The polyol component (a) in the present invention may further contain a high molecular polyol and a low molecular polyol other than the above (a11) to (a13).
Examples of the polymer polyol include Mn 1,000 to 8,000, for example, (i) low molecular polyol, (ii) polyphenol and (iii) low molecular amine AO (described above) and / or lactone (C4˜ 15) Adducts and polyols such as (i) (poly) condensates (polyester polyols) of polycarboxylic acids. These polymer polyols can be used alone or in combination.

  Examples of the lactone (C4-15) include δ-valerolactone, β-methyl-δ-valerolactone, ε-caprolactone, α-methyl-ε-caprolactone, β-methyl-ε-caprolactone, γ-methyl-ε. -Caprolactone, β, δ-dimethyl-ε-caprolactone, 3,3,5-trimethyl-ε-caprolactone, enanthlactone, dodecanolactone and the like.

Examples of the polycarboxylic acid include dicarboxylic acids [aliphatic dicarboxylic acids [C2-30, such as oxalic acid, succinic acid, adipic acid, sebacic acid, dodecenyl succinic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, maleic acid. Acid, fumaric acid, dimer acid, alkenyl succinic acid (dodecenyl succinic acid, pentadecenyl succinic acid, octadecenyl succinic acid etc.), alkyl succinic acid (decyl succinic acid, dodecyl succinic acid, octadecyl succinic acid etc.)], aromatic Group dicarboxylic acids (C8-20, such as phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid)], etc.]; trivalent or higher polycarboxylic acids [aliphatic tricarboxylic acids (C6-20, such as tricarballylic acid, Hexanetricarboxylic acid), aromatic tri- Tetracarboxylic acid (C9～12, such as trimellitic acid, pyromellitic acid) and the like, etc.] and the like.

  Examples of the low molecular polyol include the above (i) and the AO (above) and / or lactone (above) adducts of (i), (ii) and (iii), and polyols such as the polyester polyol. (Mn less than 1,000). These low molecular polyols can be used alone or in combination.

  The proportion of (a1) in the polyol component (a) is preferably 5 to 95% by weight, more preferably 10 to 90% by weight from the viewpoint of mechanical strength, rubber elasticity and flexibility of the millable urethane rubber described later.

The isocyanate component (b) includes the following poly (n = 2 to 3, preferably 2) isocyanates.
(B1) Aromatic polyisocyanate C (excluding carbon in the isocyanate group, the same shall apply hereinafter) 6 to 20, for example, tolylene diisocyanate (diisocyanate is abbreviated as DI in the following) (TDI), 4,4′- and / or 2,4′-diphenylmethane DI (MDI), naphthylene DI (NDI);
(B2) araliphatic polyisocyanates C8-15, such as diethylbenzene DI, m- and / or p-xylylene DI (XDI), α, α, α ′, α′-tetramethylxylylene DI (TMXDI);
(B3) Aliphatic polyisocyanate C2-18, such as ethylene DI, tetramethylene DI, hexamethylene DI (HDI), dodecamethylene DI, 2,2,4-trimethylhexane DI, lysine DI, 2,6-diisocyanatome Tilcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate;
(B4) Cycloaliphatic polyisocyanate C4-15, such as isophorone DI (IPDI), dicyclohexylmethane-4,4′-DI (hydrogenated MDI), cyclohexane DI, methylcyclohexane DI (hydrogenated TDI), bis (2- Isocyanatoethyl) 4-cyclohexene-1,2-dicarboxylate;
(B5) Modifications of the above polyisocyanates (carbodiimide modification, uretdione modification, uretoimine modification, urea modification, burette modification, isocyanurate modification, etc.).
Of these, aromatic polyisocyanates and alicyclic polyisocyanates are preferable from the viewpoint of heat resistance and water resistance, more preferable are aromatic DI and alicyclic DI, and particularly preferable is TDI, 4,4′-. And / or 2,4′-MDI, IPDI and hydrogenated MDI.

  In the production of the millable urethane resin (A), the reaction ratio [NCO / OH equivalent ratio] of the isocyanate component (b) and the polyol component (a) is preferably from the viewpoint of the mechanical strength and moldability of the millable urethane rubber described later. 0.8 / 1 to 1.0 / 1, more preferably 0.9 / 1 to 0.98 / 1. The reaction rate is a final reaction rate, and usually does not change depending on the production method (one-shot method or prepolymer method) described later.

Examples of the method for producing the millable urethane resin (A) include commonly used methods (one-shot method, prepolymer method, etc.). Among these, the prepolymer is preferred from the viewpoint of less variation in the quality of (A). Is the law. Next, the manufacturing method by a prepolymer method is illustrated.
First, a part of the polyol component (a) and the isocyanate component (b) are urethanized by an ordinary method at 70 to 150 ° C., preferably at an NCO / OH equivalent ratio of 1.2 / 1 to 10.0 / 1. It is made to react and an isocyanate group both terminal prepolymer is obtained. The isocyanate group content [NCO content (% by weight)] in the prepolymer is preferably 2 to 15%, more preferably 3 to 10% from the viewpoint of increasing the molecular weight of the millable urethane resin and stabilizing the molecular weight distribution. is there.
Next, the prepolymer and the remainder of the polyol component (a) are mixed and subjected to a urethanization reaction on the surface of the thermoplastic resin film (B) having a melting point of 60 to 110 ° C. or in a bag [reaction ratio Is reacted so as to achieve the above-mentioned final reaction rate. In a curing furnace, the millable urethane resin (A) is obtained by curing at 50 to 100 ° C., more preferably 60 to 90 ° C., for 0.5 to 10 hours. The method of reacting and curing on the surface of the thermoplastic resin film (B) includes a method of forming the millable urethane resin (A) by attaching the film to the inner surfaces of the upper mold and the lower mold of the mold.

  The melting point of (B) is 60 to 110 ° C, preferably 70 to 100 ° C. If the melting point of (B) is less than 60, (B) melts due to the heat of urethanation reaction, and if it exceeds 110 ° C, (B) will not melt during the production of millable urethane rubber, and the moldability and mechanical properties of the millable urethane rubber will deteriorate. To do.

As (B), polyolefin resin [polyethylene [high density polyethylene (hereinafter abbreviated as HDPE), low density polyethylene (hereinafter abbreviated as LDPE), linear low density polyethylene (hereinafter abbreviated as LLDPE)], polypropylene, etc.], Polystyrene resin, acrylic resin (for example, polymethyl methacrylate), polyester resin (polyethylene terephthalate, polybutylene terephthalate, etc.), polyamide resin (nylon 6, nylon 11, nylon 12, nylon 66, etc.), acrylonitrile-butadiene-styrene resin ( Hereinafter abbreviated as ABS resin), ethylene-vinyl acetate copolymer resin (hereinafter abbreviated as EVA), chlorinated polyolefin resin (polyvinyl chloride, polyvinylidene chloride, etc.) and polybutadiene resin (hereinafter abbreviated as PBD) [1, 4 And / or 1,2-polybutadiene resin], and the like.
Among these, those having an unsaturated bond are preferred from the viewpoint of reacting with a vulcanizing agent at the time of manufacturing a millable urethane rubber described later and being incorporated into the matrix of the millable urethane rubber and contributing to mechanical properties, and more preferably PBD, particularly preferred is 1,2-PBD.

  The ratio of the thermoplastic resin film (B) based on the weight of the millable urethane resin (A) is preferably 0.01 to 10%, more preferably from the viewpoint of the film strength before use and the heat resistance of the millable urethane rubber described later. 0.2 to 8%, particularly preferably 0.1 to 5%.

In (B), a lubricant and a filler can be contained as necessary from the viewpoint of suppressing the tackiness of the film and improving the strength of the film. As the lubricant, fatty acid amide [saturated fatty acid amide (C4-30, such as stearic acid amide, lauric acid amide), unsaturated fatty acid amide (C4-30, such as oleic acid amide, linoleic acid amide)], fatty acid alkali metal salt [Saturated fatty acids (C4-30, such as stearic acid, lauric acid) and unsaturated fatty acids (C4-30, such as oleic acid, linoleic acid) alkali metal (for example, calcium, magnesium, zinc) salts, etc.] .
Examples of the filler include carbon black, talc, calcium carbonate, anhydrous silicic acid, hydrous silicic acid, and clay.
The amount used based on the weight of (B) is usually 10% or less, preferably 0.1 to 5% for the lubricant.
The filler is usually 10% or less, preferably 0.1 to 5%.

In producing the millable urethane resin (A), various urethanization reaction catalysts can be used as necessary.
Examples of the catalyst include tertiary amines [C6-20, such as triethylamine, triethylenediamine, bis (dimethylaminoethyl) ether, N-methylmorpholine, dimethylaminomethylphenol, N-methyl-N-dimethylaminoethylpiperazine, pyridine and the like. ] And these acid block compounds, metal salts of carboxylic acids (C2-20) (sodium acetate, lead octylate, zinc octylate, iron octylate, bismuth octylate, iron naphthenate, cobalt naphthenate, stannous octoate , Dibutyltin dilaurate, etc.), alkali metal or alkaline earth metal alkoxide or phenoxide (C1-12, such as sodium methoxide, sodium phenoxide), quaternary ammonium salt (C4-12, such as tetraethylhydroxyl) Nmonium), imidazole compounds (C3-12, such as imidazole, 2-ethyl-4-methylimidazole), chelate metal salts (C5-20, such as acetylacetone zinc, acetylacetone iron), and organic compounds containing metals such as tin and antimony Examples thereof include metal compounds (C3-30, such as tetraphenyltin and tributylantimony oxide). These catalysts can be used alone or in combination.
The amount of the urethanization catalyst used is usually 5% or less, preferably 0.001 to 3%, based on the weight of (A).

The millable urethane rubber of the present invention is obtained by kneading a millable urethane resin (A) and a vulcanizing agent, or the millable urethane resin (A) and a vulcanizing agent, if necessary, with a polymer elastic body.
As the vulcanizing agent, those usually used for rubber vulcanization may be used. Sulfur, sulfur chloride, organic peroxides (C4-24, such as benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, lauryl peroxide, Cyclohexanone peroxide, t-butyl perbenzoate, t-butyl hydroperoxide, t-butylbenzene peroxide, cumene hydroperoxide, t-butyl peroctoate), oxime (C6-20, such as p-quinone dioxime, p, p′-dibenzoylquinonedioxime), metal oxides (magnesia, risurge, etc.), alkylphenol resin [trade name “Tacquirol 201” (manufactured by Taoka Chemical Co., Ltd.], etc.], polythiol compound [TMP trithioglyco Rate, TMP tri (3-mercapto Propionate), glycol dimercaptopropionate, glycol dimercaptoacetate, PE tetrathioglycolate, diPE hexa (3-mercaptopropionate), etc.], polyamine compounds (aldehyde-amine condensates, guanidine compounds, etc.), azo Examples thereof include azobisisobutyronitrile, 2-t-butylazo-2-cyano-4-methylpentane, 4-t-butylazo-4-cyano-valeric acid, and the like. These vulcanizing agents can be used alone or in combination of two or more.
Of these vulcanizing agents, sulfur, combined use of sulfur and other vulcanizing agents and peroxides, and sulfur are more preferable from the viewpoint of ease of handling and the like.
The amount of the vulcanizing agent used is usually 0.1 to 10%, preferably 0.5 to 8% based on the weight of (A).

  Examples of the polymer elastic body include natural rubber, synthetic rubber [styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber, butyl rubber, chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene-diene rubber. , Butyl rubber, etc.] and recycled rubbers thereof.

Among the above polymer elastic bodies, a synthetic rubber having a solubility parameter (solubility parameter by Fedors method, hereinafter abbreviated as SP value) is preferably 8.4 or more from the viewpoint of compatibility with the millable urethane resin (A). More preferred are SBR, CR, and NBR.
Here, the SP value is represented by the square root of the ratio between the cohesive energy density and the molecular volume as described below.

[SP] = (ΔE / V) 1/2

In the formula, ΔE represents the cohesive energy density, and V represents the molecular volume. Robert F. Fedor
The SP value calculated by s et al. is, for example, Polymer engineering a
nd science Vol. 14, pp. 147-154.
The amount of the polymer elastic body used is usually 60% or less based on the weight of (A), and preferably 1 to 50% from the viewpoint of the extrudability of the millable urethane rubber.

  In the millable urethane rubber of the present invention, the filler, pigment, softener, vulcanization accelerator, vulcanization accelerator, factice, anti-aging agent, and dehydrating agent are added as necessary as long as the effects of the present invention are not impaired. One or two or more rubber additives selected from the group consisting of:

  Examples of pigments include inorganic pigments (titanium oxide, bengara, yellow lead, cadmium sulfide, ultramarine, etc.), and organic pigments (azo, phthalocyanine, quinacridone, dioxazine, etc.); softeners include lubricating oils, fatty acids Oil, mineral oil (paraffinic oil, naphthenic oil, aromatic oil, petroleum asphalt, etc.), tar softener (tar, coumarone-indene resin, etc.), ester softener (phthalic acid derivative oil, adipic acid derivative) Oil, benzoic acid derivative oil, sebacic acid derivative oil, maleic acid derivative oil, fumaric acid derivative oil, trimellitic acid derivative oil, citric acid derivative oil, oleic acid derivative oil, ricinoleic acid derivative oil, stearic acid derivative oil, phosphoric acid Derivative oil, glycolic acid derivative oil, etc.), synthetic tree System softener (phenol - formaldehyde resins, xylene - formaldehyde resins, polyester resins, epoxy resins, etc.) and the like;

Vulcanization accelerators include guanidine compounds (diphenylguanidine, diorthotolylguanidine, etc.), thiazole compounds (2-mercaptobenzothiazole, dibenzothiazyl disulfide, etc.), thiuram compounds (tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethyl). Thiuram monosulfide, dipentamethylene thiuram tetrasulfide, etc.), sulfenamide compounds (N-cyclohexyl-2-benzothiazole sulfenamide, Nt-butyl-2-benzothiazole sulfenamide, etc.), metal compounds (dibutyl) Zinc dithiocarbamate, 2-mercaptobenzothiazole zinc salt, dibenzothiazyl disulfide zinc chloride complex, etc.);
Examples of vulcanization accelerators include C8-24 fatty acids and derivatives thereof (stearic acid, oleic acid, lauric acid, zinc stearate, etc.), metal oxides (zinc oxide, etc.), metal salts (zinc carbonate, etc.), etc .;

The factices include black sub, white sub, candy sub and sulfur-free factis;
Anti-aging agents include amines (N-phenyl-α-naphthylamine, N-phenyl-β-naphthylamine, N-phenyl-N′-isopropyl-p-phenylenediamine, 2,2,4-trimethyl-1,2- Dihydroquinoline, etc.), amine ketone (reaction product of diphenylamine and acetone, etc.), the hindered phenol compound, dithiocarbamate (such as nickel dibutyldithiocarbamate), etc .;
Examples of the dehydrating agent include calcium oxide, calcium sulfate (hemihydrate gypsum), calcium chloride, molecular sieve, and the like.

The total amount of the rubber additive based on the total weight of the millable urethane rubber is usually 100% or less, preferably 0.01 to 60%.
The amount of each rubber additive used is usually 60% or less, preferably 5 to 50% for fillers; usually 5% or less, preferably 0.1 to 2% for pigments; In the following, preferably 3 to 10%; vulcanization accelerator, vulcanization acceleration aid, factice, anti-aging agent and dehydrating agent are each usually 5% or less, preferably 0.1 to 3%.

The millable urethane rubber of the present invention, for example, using a Banbury mixer or kneader, millable urethane resin (A), and optionally a polymer elastic body, a part of the rubber additives (softener, vulcanization accelerator, Kneading so that the temperature after kneading is 80 to 120 ° C., etc., and then vulcanizing agent and, if necessary, vulcanization accelerator, remaining additives for rubber, and other additives (dehydrating agent) Etc.) on a roll until the appearance is uniform, and obtained by extrusion molding or press molding.
The molding temperature is set according to the type of vulcanizing agent, but is preferably 140 to 200 ° C. from the viewpoint of shortening the vulcanization time and the mechanical strength of the millable urethane rubber.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. In the following, “part” means “part by weight” and “%” means “% by weight”.

The composition and symbols of the raw materials used in the following examples and comparative examples are as follows.
Polyalkylene polyol (1): polytetramethylene glycol (Mn 1,000)
Polyalkylene polyol (2): PO adduct of bisphenol A (Mn 2,000)
Polyester polyol (1): Polycaprolactone (Mn2,000) [trade name “Placcel 220”, manufactured by Daicel Chemical Industries, Ltd.]
Adsorbent: Synthetic magnesium silicate [trade name “KYOWARD 600”, manufactured by Kyowa Chemical Industry Co., Ltd.]
Catalyst (1): Lead octylate PBD film (B-1): 1,2-PBD film bag having a thickness of 0.04 mm, a width of 500 mm, and a length of 800 mm (melting point: 90 ° C.) [trade name “M ELBAG- M ", manufactured by JSR Trading Co., Ltd.]
PBD film (B-2): 1,2-PBD film bag having a thickness of 0.04 mm, a width of 500 mm, and a length of 800 mm (melting point: 68 ° C.) [trade name “MELBAG-SS”, JSR Trading Co., Ltd. Made]
LDPE film (B-3): LDPE pellet (melting point 106 ° C.) [trade name “U
BE polyethylene J2516 "manufactured by Ube Maruzen Polyethylene Co., Ltd.] is a 0.04 mm film, and is formed into a bag shape having a width of 500 mm and a length of 800 mm. LLDPE film (B-4): LLDPE pellet (melting point: 122 ° C) [Product name
“Sumikasen-L FS240” manufactured by Sumitomo Chemical Co., Ltd.] Polymer elastic body (1): SBR [trade name “JSR SL552”, manufactured by JSR Corporation]
Filler (1): Carbon black [trade name “Asahi # 50”, Asahi Carbon Co., Ltd.
Made]
Vulcanization accelerator (1): stearic acid
(2): Zinc oxide softener (1): Aromatic mineral oil [trade name "Dyna Process Oil AC-
460 ", manufactured by Idemitsu Kosan Co., Ltd.]
(2): Dipropylene glycol dibenzoate [trade name “Ade
Casser PN6120 ", manufactured by Asahi Denka Kogyo Co., Ltd.]
Vulcanizing agent (1): Sulfur vulcanization accelerator (1): Dibenzothiazyl disulfide
(2): 2-mercaptobenzothiazole

Production Example 1
5,000 parts of polyalkylene polyol (1) and 2,050 parts of IPDI were reacted at 120 ° C. for 3 hours to obtain a prepolymer (b-1) having an NCO content of 5.0%.

Production Example 2
5,000 parts of polyalkylene polyol (2) and 2,050 parts of IPDI were reacted at 120 ° C. for 3 hours to obtain a prepolymer (b-2) having an NCO content of 8.0%.

Production Example 3
5,000 parts of polyester polyol (1) and 2,050 parts of IPDI were reacted at 120 ° C. for 3 hours to obtain a prepolymer (b-3) having an NCO content of 8.0%.

Production Example 4
5,000 parts of polyalkylene polyol (1) and 2,350 parts of 4,4′-MDI were reacted at 80 ° C. for 3 hours to obtain a prepolymer (b-4) having an NCO content of 5.0%.

Production Example 5
5,000 parts of polyalkylene polyol (2) and 2,390 parts of 4,4′-MDI were reacted at 80 ° C. for 3 hours to obtain a prepolymer (b-5) having an NCO content of 8.0%.

Production Example 6
A fully dried pressure-resistant reaction vessel was charged with 262 parts of GR monoallyl ether and 0.2 part of potassium hydroxide, sealed, and then dehydrated under reduced pressure at 100 ° C. to confirm that the water content was 0.05% or less. After reducing the internal temperature of the vessel to 95 ° C. under reduced pressure, 738 parts of PO was introduced from the bottom of the vessel in the range of 90 to 100 ° C. and reacted at 90 to 100 ° C. for 2 hours. After cooling to 70 ° C., nitrogen was blown from the top of the reaction vessel, and 1% water was added and stirred and mixed in an atmosphere with a gas phase oxygen concentration of 0%. Subsequently, 5 parts of an adsorbent was added and stirred and mixed at 70 to 80 ° C. to adsorb the potassium hydroxide catalyst, followed by filtration under nitrogen pressure (gas phase oxygen concentration 0%). 0.5 part of 2,6-di-t-butyl-4-methylphenol (antioxidant) was added and heated at a gas phase oxygen concentration of 0% to a temperature range of 95 to 105 ° C., followed by dehydration under reduced pressure. When the water content reached 0.05%, the mixture was immediately cooled to obtain an unsaturated group-containing polyol (a1-1) having a hydroxyl value of 224.4 mgKOH / g (only numerical values are shown below).

Production Example 7
In Production Example 6, containing 262 parts of GR monoallyl ether and 133 parts of DPG and PO738 parts in the same manner as in Production Example 6 except that a mixture of AGE 226 parts and PO641 parts is contained. A polyol (a1-2) was obtained.

Production Example 8
In Production Example 6, 262 parts of GR monoallyl ether was replaced with 133 parts of DPG, and 738 parts of PO were replaced with AGE 113 parts from the bottom of the kettle in the range of 90 to 100 ° C. and reacted at 90 to 100 ° C. for 2 hours. I let you. Next, a mixture of 317 parts of EO and 437 parts of PO was introduced from the bottom of the kettle in the range of 90 to 100 ° C., and reacted at 90 to 100 ° C. for 2 hours. Thereafter, in the same manner as in Production Example 6, an unsaturated group-containing polyol (a1-3) having a hydroxyl value of 112.2 was obtained.

Production Example 9
In a reaction vessel equipped with a stirrer, 270 parts of unsaturated group-containing polyol (a1-1), 67 parts of polyalkylene polyol (1) and 2 parts of catalyst (1) were charged, stirred, mixed and heated to 70 ° C. . Next, 1,000 parts of prepolymer (b-1) whose temperature was adjusted to 70 ° C. was added (NCO / OH equivalent ratio = 0.98 / 1), and after stirring, the PBD film (B-1) (bag) immediately After pouring in and sealing, it was made to react at 80 degreeC for 10 hours, and the millable urethane resin (A-1) was obtained. The proportion of (B-1) based on the weight of (A-1) was 2.2%.

Production Example 10
In Production Example 9, in place of 270 parts of the unsaturated group-containing polyol (a1-1) and 67 parts of the polyalkylene polyol (1), 304 parts of the unsaturated group-containing polyol (a1-2) and polyalkylene polyol (1) 304 And in place of PBD film (B-1), except that LDPE film (B-3) (bag) was used (NCO / OH equivalent ratio = 0.98 / 1). A millable urethane resin (A-2) was obtained. The proportion of (B-3) based on the weight of (A-2) was 1.8%.

Production Example 11
In Production Example 9, instead of 270 parts of unsaturated group-containing polyol (a1-1), 67 parts of polyalkylene polyol (1) and 1,000 parts of prepolymer (b-1), an unsaturated group-containing polyol (a1- 3) Millable urethane resin (A-3) was prepared in the same manner as in Production Example 9 except that 970 parts and 1,000 parts of prepolymer (b-2) were used (NCO / OH equivalent ratio = 0.98 / 1). )
The proportion of (B-1) based on the weight of (A-3) was 1.5%.

Production Example 12
In Production Example 9, 296 parts of TMP monoallyl ether and prepolymer (b-1) were replaced with 270 parts of unsaturated group-containing polyol (a1-1), 67 parts of polyalkylene polyol (1) and 1,000 parts of prepolymer (b-1). Millable urethane resin (A-4) was obtained in the same manner as in Production Example 9 except that 1,000 parts of polymer (b-3) was used (NCO / OH equivalent ratio = 0.98 / 1).
The proportion of (B-1) based on the weight of (A-4) was 2.3%.

Production Example 13
In a reaction vessel equipped with a stirrer, 54.5 parts of unsaturated group-containing polyol (a1-1), 13.5 parts of polyalkylene polyol (1), and 0.04 part of catalyst (1) were charged and stirred. And heated to 60 ° C. Next, 201.9 parts of prepolymer (b-1) whose temperature was adjusted to 60 ° C. was poured into a PBD film (B-2) (bag), sealed, and reacted at 60 ° C. for 10 hours to produce a millable urethane resin ( A-5) was obtained. The proportion of (B-2) based on the weight of (A-5) was 10%.

Production Example 14
In Production Example 9, 270 parts of unsaturated group-containing polyol (a1-1), 67 parts of polyalkylene polyol (1), 1,000 parts of prepolymer (b-1) and 2 parts of catalyst were used instead of unsaturated groups. Polyol (a1-2) 3,040 parts, polyalkylene polyol (1) 3,040 parts, prepolymer (b-4) 10,000 parts and catalyst 20 parts (NCO / OH equivalent ratio = 0.98) / 1) Except that, it was carried out in the same manner as in Production Example 9 to obtain a millable urethane resin (A-6). The proportion of (B-1) based on the weight of (A-6) was 0.2%.

Production Example 15
In Production Example 9, 296 parts of TMP monoallyl ether and prepolymer (b-1) were replaced with 270 parts of unsaturated group-containing polyol (a1-1), 67 parts of polyalkylene polyol (1) and 1,000 parts of prepolymer (b-1). Millable urethane resin (A-7) was obtained in the same manner as in Production Example 9 except that 1,000 parts of the polymer (b-5) was used (NCO / OH equivalent ratio = 0.98 / 1).
The proportion of (B-1) based on the weight of (A-7) was 2.2%.

Comparative production example 1
Millable urethane resin (ratio A-1) was obtained in the same manner as in Production Example 9 except that PBD film (B-1) was replaced with LLDPE film (B-4) (bag) in Production Example 9. The ratio of (B-4) based on the weight of (Ratio A-1) was 2.2%.

Comparative production example 2
A mixing vessel equipped with a stirrer was charged with a polyol component consisting of 270 parts of polyalkylene polyol (1), 67 parts of polyalkylene polyol (1), and 2 parts of catalyst (1). Heated. In another mixing vessel, 1,000 parts of prepolymer (b-1) was placed, and after substitution with nitrogen, the mixture was heated to 70 ° C. with stirring. Next, using the pumps from the two mixing vessels, mixing into the twin screw extruder through the mixer section so that the NCO / OH equivalent ratio of the prepolymer (b-1) and the polyol in the polyol component is 0.98 / 1. The liquid was continuously supplied. The temperature of the twin screw extruder was 210 ° C., and the millable urethane resin (ratio A-2) was extruded from the extruder into a sheet shape.

Comparative production example 3
In Production Example 9, instead of 270 parts of unsaturated group-containing polyol (a1-1), 67 parts of polyalkylene polyol (1), 1,000 parts of prepolymer (b-1) and PBD film (B-1), The same procedure as in Production Example 9 was conducted except that 296 parts of TMP monoallyl ether, 1,000 parts of prepolymer (b-5) and LLDPE film (B-4) were used, and millable urethane resin (ratio A-3) was used. Obtained. The ratio of (B-4) based on the weight of (Ratio A-3) was 2.2%.

Comparative production example 4
In Comparative Production Example 2, millable urethane resin was prepared in the same manner as Comparative Production Example 2 except that 1,000 parts of prepolymer (b-4) was used instead of 1,000 parts of prepolymer (b-1). (Ratio A-4) was obtained.

Examples 1-9
According to the composition of Table 1, <kneading component 1> among the blended components was kneaded for 10 minutes with a Banbury mixer. Next, <kneading component 2> was added and kneaded for 10 minutes with two kneading rolls. The kneaded product was extruded into a bar shape having a cross section of 20 mm × width 20 mm using an extruder, and then heated at 160 ° C. for 10 minutes to obtain millable urethane rubbers (1) to (9).

Comparative Examples 1-4
According to the composition of Table 1, millable urethane rubbers (Ratio 1) to (Ratio 4) were obtained in the same manner as in Examples 1-9.

About each molded article of Examples 1-9 and Comparative Examples 1-4, extrusion moldability and a cross-sectional state were measured. The results are shown in Table 1. The test method is as follows.
<Test method>
(1) Extrudability According to ASTM D2230-96 (2002) e1 (B evaluation), a garbage die (an evaluation die used in the ASTM. Extrudability is evaluated for an extruded product extruded from the die). The extrusion moldability of the extruded product was evaluated according to the following criteria.
<Evaluation criteria>
The following criteria [1] and [2] were evaluated according to the evaluation criteria described in the ASTM.
That is, the evaluation result of [1] and the evaluation result of [2] are described in order. For example, if either [1] or [2] is excellent, the evaluation is “10A”, [1] and [2] ] Is described as “1E”.
[1] Sharpness and continuity of 30 ° edge portion. Evaluated in 10 grades of 1 (bad) to 10 (good).
[2] Surface smoothness A five-step evaluation of A (good) to E (bad).
(2) Cross-sectional state The millable urethane rubber extruded product was cut in the length direction, and it was visually confirmed whether there was any unmelted film in the millable urethane rubber. The cross-sectional state was evaluated according to the following criteria.
<Evaluation criteria>
○: No unmelted film ×: Unmelted film (3) Mechanical strength (tensile strength, elongation)
In accordance with “Vulcanized rubber and thermoplastic rubber-Determination of tensile properties” described in JIS K6251: 2004, No. 3 dumbbell specimens were punched from a sheet press-formed to a thickness of 2 mm and measured.

  From the results of the examples, the millable urethane rubber obtained by the production method of the present invention is excellent in moldability because no cross-linking reaction occurs during the production of the millable urethane resin, and has good mechanical properties with no unmelted film. In particular, it can be seen that a material using PBD as (B) exhibits further excellent mechanical properties, and a material added with a polymer elastic body exhibits further excellent moldability.

  The manufacturing method of the millable urethane rubber of the present invention is excellent in work efficiency, and the resulting millable urethane rubber is excellent in moldability and has good mechanical properties. Therefore, industrial rolls (such as paper transport rolls), industrial belts ( It can be suitably used for a wide range of applications such as a conveyor belt and the like, and an industrial sheet (a waste disposal site impermeable sheet and the like).

Claims (5)

A thermoplastic resin film having a melting point of 60 to 110 ° C. with a mixed liquid of a polyol component (a) and an isocyanate component (b) containing a polyol having at least one ethylenically unsaturated group in the molecular side chain A vulcanizing agent is added to the millable urethane resin (A) which is reacted and cured on the surface of (B) or in a bag, and melted, kneaded and cured without removing (B). Manufacturing method of millable urethane rubber. The production method according to claim 1, wherein the proportion of (B) based on the weight of (A) is 0.01 to 10%. The method according to claim 1 or 2, further comprising adding a polymer elastic body, melting, kneading and curing. Millable urethane rubber obtained by the production method according to claim 1. An industrial roll, belt or sheet comprising the millable urethane rubber according to claim 4.