JP2021038278A - Polyurethane for synthetic leather - Google Patents

Abstract

To provide a polyurethane for synthetic leather which is excellent in flexibility and bendability at a low temperature and chemical resistance.SOLUTION: The polyurethane for synthetic leather contains a structural unit derived from a compound having a plurality of isocyanate groups, a structural unit derived from at least one compound selected from the group consisting of polyols and polyamines, and a structural unit derived from a polyether polycarbonate diol represented by the following formula (A) and having a number average molecular weight determined from a hydroxyl value of 600 or more. (R represents a C2-10 divalent hydrocarbon group; n represents an integer of 2-30; and m represents an integer of 1-20.)SELECTED DRAWING: None

Description

In the present invention, a polyurethane for synthetic leather having improved flexibility, flexibility and chemical resistance at low temperature by using a polyether polycarbonate diol having a specific structure as a raw material, and a synthetic leather using this polyurethane for synthetic leather. Regarding laminates.

In recent years, synthetic leather has been widely used as a fashion material and an interior material because it has a texture and durability equal to or higher than that of natural leather. Artificial leather or synthetic leather is formed of a base material made of non-woven fabric, woven or knitted fabric, a resin layer laminated or filled therein, a porous resin film layer, an adhesive layer, a skin layer, or the like. Polyurethane is generally used as the resin used for each of these layers.

Conventionally, the raw materials for the main soft segment of polyurethane produced on an industrial scale are ether type represented by polytetramethylene ether glycol, polyester polyol type represented by adipate ester, and polylactone represented by polycaprolactone. It is classified into a type or a polycarbonate type typified by a polycarbonate diol (Non-Patent Document 1).
For example, an ether type polyurethane for synthetic leather using polytetramethylene ether glycol has been proposed (Patent Document 1).
Further, a polycarbonate type polyurethane for synthetic leather using a polycarbonate diol has been proposed (Patent Document 2).

Ether-type polyurethane is said to be excellent in flexibility and elasticity, but inferior in chemical resistance. On the other hand, polycarbonate-type polyurethane typified by polycarbonate diol is considered to be the best durable grade in terms of chemical resistance, and is widely used as a high-quality resin for synthetic leather.

However, currently widely available polycarbonate diols are mainly polycarbonate diols synthesized from 1,6-hexanediol, which have high crystallinity and therefore have soft segment cohesiveness when made into polyurethane. There was a problem that the flexibility, elongation, and flexibility were poor, especially at low temperatures, and the application was limited.

An aqueous polyurethane-polyurea dispersion based on a polyether polycarbonate polyol has been proposed as a coating material having excellent hydrolysis stability, but the specific composition and effect for the purpose of polyurethane for synthetic leather have been clarified. (Patent Document 3).

JP 2015-189886 Japanese Unexamined Patent Publication No. 2013-108196 Special Table 2009-523867

"Basics and Applications of Polyurethane" pp. 96-106, supervised by Katsuji Matsunaga, CMC Publishing Co., Ltd., published in November 2006

Polyurethanes for synthetic leather are desired to be further improved in durability such as flexibility, flexibility, and chemical resistance, especially at low temperatures, in their applications. In the conventional polyurethane for synthetic leather, it is difficult to achieve both flexibility and flexibility at low temperature and durability such as chemical resistance.

An object of the present invention is to provide a polyurethane for synthetic leather having excellent flexibility, flexibility and chemical resistance at low temperatures, and a synthetic leather laminate using the polyurethane for synthetic leather.

As a result of diligent studies to solve the above problems, the present inventor has found that the above problems can be solved by producing polyurethane for synthetic leather using a specific polyether polycarbonate diol as a raw material. It was.

The present invention has been achieved based on such findings, and the gist of the present invention is as follows.

[1] A structural unit derived from a compound having a plurality of isocyanate groups, a structural unit derived from at least one compound selected from the group consisting of polyols and polyamines, and a hydroxyl group represented by the following formula (A). Polyurethane for synthetic leather containing a structural unit derived from a polyether polycarbonate diol having a number average molecular weight of 600 or more determined from the value.

(In the above formula (A), R represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n is an integer of 2 to 30, and m is an integer of 1 to 20. ), Multiple Rs may be the same or different.)

[2] The polyurethane for synthetic leather according to [1], wherein R in the formula (A) is an n-butylene group.

[3] The polyurethane for synthetic leather according to [1] or [2], wherein n in the formula (A) is an integer of 2 to 20.

[4] The polyurethane for synthetic leather according to any one of [1] to [3], wherein m in the formula (A) is an integer of 4 to 20.

[5] At least one compound selected from the group consisting of the polyol and polyamine is at least one compound selected from the group consisting of ethylenediamine, isophoronediamine and hexamethylenediamine [1] to [4]. Polyurethane for synthetic leather described in any of.

[6] At least one compound selected from the group consisting of the polyol and polyamine is at least one selected from the group consisting of 1,4-butanediol, ethylene glycol, propylene glycol and 1,6-hexanediol. The polyurethane for synthetic leather according to any one of [1] to [4], which is a compound of.

[7] The compound having a plurality of isocyanate groups is at least one compound selected from the group consisting of 4,4'-dicyclohexylmethane diisocyanate, 1,6-hexamethylene diisocyanate and isophorone diisocyanate [1] to. The polyurethane for synthetic leather according to any one of [6].

[8] The ratio of the structural unit derived from the polyether polycarbonate diol represented by the formula (A) to the structural unit derived from the compound having a plurality of isocyanate groups is 20 to 60 mol% [1] to The polyurethane for synthetic leather according to any one of [7].

[9] A synthetic leather laminate in which a base cloth, an adhesive layer, an intermediate layer, and a skin layer containing the polyurethane for synthetic leather according to any one of [1] to [8] are laminated in this order.

[10] A synthetic leather laminate in which a base cloth, an adhesive layer, an intermediate layer containing the polyurethane for synthetic leather according to any one of [1] to [8], and an epidermis layer are laminated in this order.

According to the present invention, by using a polyether polycarbonate diol having a specific structure as a raw material, it is possible to provide a polyurethane for synthetic leather having excellent flexibility, flexibility and chemical resistance at low temperatures.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

[Polyurethane for synthetic leather]
The polyurethane for synthetic leather of the present invention (hereinafter, may be simply referred to as "polyurethane of the present invention") is derived from a compound having a plurality of isocyanate groups (hereinafter, may be referred to as "polyisocyanate compound"). A structural unit derived from at least one compound selected from the group consisting of a polyol and a polyamine (hereinafter, may be referred to as a “chain extender”), and represented by the following formula (A). , A structural unit derived from a polyether polycarbonate diol having a number average molecular weight of 600 or more determined from the hydroxyl value (hereinafter, may be referred to as "polyether polycarbonate diol (A)"), and is a polyisocyanate compound. It is produced by using a chain extender and a polyether polycarbonate diol (A) as raw materials.

(In the above formula (A), R represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n is an integer of 2 to 30, and m is an integer of 1 to 20. ), Multiple Rs may be the same or different.)

<Polyisocyanate compound>
The polyisocyanate compound used as a raw material for producing polyurethane for synthetic leather of the present invention may be any compound having two or more isocyanate groups, and various known polyisocyanate compounds such as aliphatic, alicyclic or aromatic can be mentioned. Be done.

For example, the carboxyl groups of tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate and dimer acid were converted into isocyanate groups. Aliphatic diisocyanate compounds such as dimerge diisocyanate; 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and Alicyclic diisocyanate compounds such as 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 1,5-pentamethylene diisocyanate; xylylene diisocyanate, 4,4'-diphenyldiisocyanate, Toluene diisocyanate (2,4-toluene diisocyanate, 2,6-toluene diisocyanate), m-phenylenediisocyanate, p-phenylenediisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4' -Dibenzyldiisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylenediocyanate, polymethylene polyphenyl isocyanate, phenylenediisocyanate and m-tetramethyl Examples thereof include aromatic diisocyanate compounds such as xylylene diisocyanate. These may be used alone or in combination of two or more.

Among these, 4,4'-dicyclohexylmethane diisocyanate, 1,6-hexamethylene diisocyanate and isophorone diisocyanate are preferable because the balance of the physical properties of the obtained polyurethane is preferable and they can be industrially obtained in large quantities at low cost.

<Chain extender>
The chain extender used as a raw material for producing the polyurethane of the present invention is a low molecular weight compound having at least two active hydrogens that react with an isocyanate group, and is selected from polyols and polyamines.

Specific examples thereof include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, and 1,9-nonanediol. , 1,10-decanediol, 1,12-dodecanediol and other linear diols; 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diol -1,3-Propanediol, 2-Methyl-2-propyl-1,3-Propanediol, 2,4-Heptanediol, 1,4-Dimethylolhexane, 2-Ethyl-1,3-hexanediol, 2 , 2,4-trimethyl-1,3-pentanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, dimerdiol and other diols having branched chains. Diols having an ether group such as diethylene glycol and propylene glycol; diols having an alicyclic structure such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and 1,4-dihydroxyethylcyclohexane, xylylene glycol, Diols having aromatic groups such as 1,4-dihydroxyethylbenzene and 4,4'-methylenebis (hydroxyethylbenzene); polyols such as glycerin, trimethylolpropane, pentaerythritol; N-methylethanolamine, N-ethylethanol Hydroxyamines such as amines; ethylenediol, 1,3-diaminopropane, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediol, 4,4'-diaminodicyclohexylmethane, 2-hydroxyethylpropylenediol, di-2-hydroxy Ethylethylenediol, di-2-hydroxyethylpropylenediol, 2-hydroxypropylethylenediol, di-2-hydroxypropylethylenediamine, 4,4'-diphenylmethanediol, methylenebis (o-chloroaniline), xylylene diamine, diphenyldiol, tri Polyamines such as rangeamine, hydrazine, piperazine, N, N'-diaminopiperazine; and the like can be mentioned.

One of these chain extenders may be used alone, or two or more thereof may be used in combination.

Among these, ethylenediamine, isophoronediamine, and hexamethylenediamine are preferable from the viewpoint of easy handling and controllability of the reaction.
In addition, ethylene glycol, 1,4-, is excellent in flexibility and elastic recovery due to the excellent phase separation between the soft segment and the hard segment of the obtained polyurethane, and in that it can be industrially obtained in large quantities at low cost. Butanediol, propylene glycol and 1,6-hexanediol are preferred.

<Polyester Polycarbonate Diol (A)>
The polyether polycarbonate diol (A) used as a raw material for producing the synthetic leather polyurethane of the present invention is represented by the following formula (A).
In the following formula (A), when m = 1, it is called "polyether carbonate diol" instead of "polyether polycarbonate diol", but in the present invention, it is represented by the formula (A). It is also referred to as "polyether polycarbonate diol (A)" including the polyether carbonate diol.

(In the above formula (A), R represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n is an integer of 2 to 30, and m is an integer of 1 to 20. ), Multiple Rs may be the same or different.)

In the above formula (A), R is preferably a linear or branched alkylene group having 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, and particularly preferably a butylene group having 4 carbon atoms or 2 having 5 carbon atoms. -Methylbutylene group, especially preferably n-butylene group. That is, it is preferable that RO-in the formula (A) is derived from polytetramethylene ether glycol from the viewpoints of industrial availability and excellent physical properties of the obtained polyurethane.

In the above formula (A), if n is less than 2, the flexibility of the obtained polyurethane tends to be inferior, and if it exceeds 30, the viscosity and crystallinity of the polyether polycarbonate diol become high, the handling becomes poor, and the obtained is obtained. Polyurethane tends to be less transparent. Therefore, n is 2 to 30, preferably 2 to 20, and more preferably 2 to 15.

Further, in the above formula (A), if m is less than 1, the durability of the obtained polyurethane tends to be inferior, and if it exceeds 20, the viscosity increases, which may impair the handling at the time of polyurethane formation. Therefore, m is 1 to 20, preferably 4 to 20, and more preferably 4 to 15.

The polyether polycarbonate diol (A) can be produced by polymerizing a polyoxyalkylene glycol and a carbonate compound in the presence of a catalyst according to a conventional method.

The polyoxyalkylene glycol used in the production of the polyether polycarbonate diol (A) is polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, polytetramethylene ether glycol obtained by copolymerizing 3-methyl tetrahydrofuran and tetrahydrofuran, neopentyl glycol and tetrahydrofuran. Polytetramethylene ether polyols, ethylene oxide and tetrahydrofuran copolymer polyether polyols, propylene oxide and tetrahydrofuran copolymer polyether glycols and the like are preferable from the viewpoint of the mechanical strength of the obtained polyurethane, and polytetramethylene ether glycol (PTMG) is preferable. Is more preferable.
The above-mentioned polyoxyalkylene glycol may be used alone or in combination of two or more.

The number average molecular weight (Mn) determined from the hydroxyl value of the polyoxyalkylene glycol used for producing the polyether polycarbonate diol (A) is preferably 150 to 3000, more preferably 200 to 2000, and even more preferably 250 to 1000. .. If the molecular weight is less than 150, the flexibility of the obtained polyurethane tends to be inferior, and if it exceeds 3000, the viscosity of the obtained polyether polycarbonate diol (A) becomes high, and the handleability tends to be poor. The number average molecular weight (Mn) determined from the hydroxyl value is specifically measured by the method described in the section of Examples described later.

Examples of the carbonate compound that can be used for producing the polyether polycarbonate diol (A) include, but are not limited to, dialkyl carbonate, diaryl carbonate, and alkylene carbonate as long as the effects of the present invention are not impaired. These may be one kind or a plurality of kinds. Of these, dialkyl carbonate and alkylene carbonate are preferable from the viewpoint of reactivity.

Specific examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate, ethylene carbonate and the like, and dimethyl carbonate and ethylene carbonate are preferable.

When producing the polyether polycarbonate diol (A), a transesterification catalyst can be used, if necessary, in order to promote the polymerization.
As the transesterification catalyst, any compound generally considered to have transesterification ability can be used without limitation.

Examples of ester exchange catalysts are long-periodic periodic tables such as lithium, sodium, potassium, rubidium, and cesium (hereinafter, simply referred to as "periodic table"), compounds of Group 1 metals (excluding hydrogen); Periodic Table Group 2 Metal Compounds such as Magnesium, Calcium, Strontium, and Rubidium; Periodic Table Group 4 Metal Compounds such as Titanium and Zirconium; Periodic Table Group 5 Metal Compounds such as Hafnium; Periodic Table No. 1 such as Cobalt Periodic Table Group 9 Metal Compounds such as Zinc; Periodic Table Group 12 Metal Compounds such as Aluminum; Periodic Table Group 13 Metal Compounds such as Aluminum; Periodic Table Group 14 Metal Compounds such as Germanium, Tin, Lead; Antimon, Bismus, etc. Periodic Table Group 15 Metal Compounds; Examples include lanthanide metal compounds such as lanthanum, cesium, europium, and itterbium. Of these, from the viewpoint of increasing the ester exchange reaction rate, a compound of the Group 1 metal (excluding hydrogen) of the Periodic Table, a compound of the Metal of Group 2 of the Periodic Table, a compound of the Metal of Group 4 of the Periodic Table, and a compound of the Group 5 of the Periodic Table Compounds of Group Metals, Compounds of Group 9 Metals of the Periodic Table, Compounds of Metals of Group 12 of the Periodic Table, Compounds of Metals of Group 13 of the Periodic Table, and Compounds of Metals of Group 14 of the Periodic Table are preferable. Compounds (excluding hydrogen) and compounds of Group 2 metal of the periodic table are more preferable, and compounds of Group 2 metal of the periodic table are even more preferable. Among the compounds of Group 1 metals (excluding hydrogen) in the periodic table, compounds of lithium, potassium and sodium are preferable, compounds of lithium and sodium are more preferable, and compounds of sodium are even more preferable. Among the compounds of the Group 2 metal in the periodic table, magnesium, calcium and barium compounds are preferable, calcium and magnesium compounds are more preferable, and magnesium compounds are even more preferable. These metal compounds are mainly used as hydroxides, salts and the like. Examples of salts when used as salts include halide salts such as chlorides, bromides and iodides; carboxylates such as acetates, formates and benzoates; inorganic acid salts such as carbonates and nitrates. Sulfonates such as methanesulfonic acid, toluenesulfonic acid, and trifluoromethanesulfonic acid; phosphorus-containing salts such as phosphates, hydrogen phosphates, and dihydrogen phosphates; acetylacetonate salts; and the like. The catalyst metal can also be used as an alkoxide such as methoxide or ethoxide.

Of these, preferably, acetates, nitrates, sulfates, carbonates, phosphates, hydroxides, halides, acetylacetonate salts, etc. of at least one metal selected from Group 2 metals in the periodic table. Alkoxides are used, more preferably acetates, carbonates, hydroxides and acetylacetonate salts of Group 2 metals of the periodic table, and more preferably acetates, carbonates and hydroxides of magnesium and calcium. Acetylacetonate salts are used, particularly preferably magnesium, calcium acetate, and acetylacetonate salts, and most preferably magnesium acetylacetonate.

In the production of the polyether polycarbonate diol (A), the amount of the carbonate compound used is not particularly limited, but it is usually a molar ratio to 1 mol of the total of polyoxyalkylene glycol, and the lower limit is preferably 0.35, more preferably 0. It is 50, more preferably 0.60, and the upper limit is preferably 1.00, more preferably 0.98, still more preferably 0.97. If the amount of the carbonate compound used exceeds the above upper limit, the proportion of the obtained polyether polycarbonate diol (A) whose terminal group is not a hydroxyl group may increase, or the molecular weight may not be within the predetermined range. The polymerization may not proceed until.

When the transesterification catalyst described above is used in producing the polyether polycarbonate diol (A), the amount used is preferably an amount that does not affect the performance even if it remains in the obtained polycarbonate diol.

The upper limit of the weight ratio of the metal to the weight of the raw material polyoxyalkylene glycol is preferably 500% by weight, more preferably 100% by weight, and more preferably 50% by weight. More preferably, it is particularly preferably 10 wt ppm. On the other hand, the lower limit is preferably 0.01 wt ppm, more preferably 0.1 wt ppm, and even more preferably 1 wt ppm, as the amount at which sufficient polymerization activity can be obtained.

The reaction temperature at the time of the transesterification reaction can be arbitrarily adopted as long as a practical reaction rate can be obtained. Usually, the lower limit of the reaction temperature is preferably 70 ° C., more preferably 100 ° C., and even more preferably 130 ° C. The upper limit of the reaction temperature is usually preferably 250 ° C., more preferably 230 ° C., and even more preferably 200 ° C. By setting the reaction temperature to the above upper limit or less, it is possible to prevent quality problems such as coloring of the obtained polyether polycarbonate diol (A) and formation of an ether structure.

Furthermore, the reaction temperature is preferably 180 ° C. or lower, more preferably 170 ° C. or lower, and further preferably 160 ° C. or lower throughout the entire process of the transesterification reaction for producing the polyether polycarbonate diol (A). preferable. By setting the reaction temperature to 180 ° C. or lower throughout the entire process, it is possible to prevent easy coloring depending on the conditions.

The transesterification reaction can be carried out at normal pressure, but the transesterification reaction is an equilibrium reaction, and the reaction can be biased to the production system by distilling the produced light boiling component out of the system. Therefore, usually, in the latter half of the reaction, it is preferable to adopt a reduced pressure condition and carry out the reaction while distilling off the light boiling component. Alternatively, it is also possible to carry out the reaction while distilling off the light boiling component generated by gradually lowering the pressure from the middle of the reaction. In particular, it is preferable to increase the degree of reduced pressure at the end of the reaction to distill off by-produced monoalcohols, phenols, cyclic carbonates and the like.
The upper limit of the reaction pressure at the end of the reaction at this time is preferably 10 kPa, more preferably 5 kPa, and even more preferably 1 kPa.
In order to effectively distill off the light boiling component, the reaction can be carried out while flowing an inert gas such as nitrogen, argon or helium into the reaction system.

When a low boiling carbonate compound is used in the transesterification reaction, the reaction is carried out near the boiling point of the carbonate compound at the beginning of the reaction, and as the reaction progresses, the temperature is gradually raised to further proceed the reaction. The method can also be adopted. By doing so, it is possible to prevent distillation of the unreacted carbonate compound at the initial stage of the reaction.

Furthermore, for the purpose of preventing distilling of these raw materials, it is also possible to attach a rectification tower and a reflux tube to the reactor, distill and separate the carbonate compound and the light boiling component, and carry out the reaction while refluxing the carbonate compound. In this case, the charged raw materials are not lost and the amount ratio of the reagent can be accurately adjusted.

The polymerization reaction can be carried out by a batch method or a continuous method, but it is preferable to carry out the polymerization reaction by a continuous method from the viewpoint of product stability and the like. The apparatus to be used may be of any type of tank type, tube type and tower type, and a known polymerization tank or the like equipped with various stirring blades can be used. The atmosphere during the temperature rise of the apparatus is not particularly limited, but from the viewpoint of product quality, it is preferably carried out in an inert gas such as nitrogen gas under normal pressure or reduced pressure.

The polymerization reaction is completed when the target molecular weight is reached while measuring the molecular weight of the produced polyether polycarbonate diol (A). The reaction time required for the polymerization varies greatly depending on the presence or absence and type of the polyoxyalkylene glycol, carbonate compound, and catalyst used, and therefore cannot be unconditionally specified, but is usually preferably 50 hours or less. It is more preferably 30 hours or less, and further preferably 20 hours or less.

When a catalyst is used in the polymerization reaction, the catalyst usually remains in the obtained polyether polycarbonate diol (A), and the remaining catalyst may make it impossible to control the polyurethaneization reaction. In order to suppress the influence of the remaining catalyst, it is preferable to add a catalyst deactivating agent such as a phosphorus compound having a molar equivalent to that of the transesterification catalyst used to inactivate the transesterification catalyst. Further, after the addition of the catalyst deactivator, the transesterification catalyst can be efficiently inactivated by heat treatment or the like as described later.

Examples of the phosphorus-based compound used for inactivating the ester exchange catalyst include inorganic phosphoric acid such as phosphoric acid and phosphoric acid, dibutyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, and subphosphate. Examples thereof include organic phosphate esters such as triphenyl phosphate. One of these may be used alone, or two or more thereof may be used in combination.

The amount of the phosphorus compound used is not particularly limited, but may be approximately the same molar amount as the transesterification catalyst used, and specifically, the upper limit is preferably 1 mol with respect to 1 mol of the transesterification catalyst used. It is 5 mol, more preferably 2 mol, and the lower limit is preferably 0.8 mol, more preferably 1.0 mol. When a smaller amount of the phosphorus compound is used, the inactivation of the ester exchange catalyst in the reaction product is not sufficient, and when the obtained polyether polycarbonate diol (A) is used as a raw material for polyurethane production. , The reactivity of the polyether polycarbonate diol (A) to the isocyanate group may not be sufficiently reduced. Further, if a phosphorus compound exceeding this range is used, the obtained polyether polycarbonate diol (A) may be colored.

The inactivation of the transesterification catalyst by adding a phosphorus-based compound can be carried out at room temperature, but it is more efficient when heat-treated. The temperature of this heat treatment is not particularly limited, but the upper limit is preferably 180 ° C, more preferably 150 ° C, further preferably 120 ° C, particularly preferably 100 ° C, and the lower limit is preferably 50 ° C, more preferably. Is 60 ° C, more preferably 70 ° C. If the temperature is lower than this, the inactivation of the transesterification catalyst takes time and is not efficient, and the degree of inactivation may be insufficient. On the other hand, at a temperature exceeding 180 ° C., the obtained polyether polycarbonate diol (A) may be colored. The time for reacting with the phosphorus compound is not particularly limited, but is usually 1 to 5 hours.

The amount of catalyst remaining in the polyether polycarbonate diol (A) is preferably 100 ppm by weight or less, particularly preferably 10 wt ppm or less in terms of metal, from the viewpoint of controlling the polyurethaneization reaction. On the other hand, the required amount of catalyst is preferably 0.01 wt ppm or more, particularly 0.1 wt ppm or more, particularly 5 wt ppm or more in terms of metal.

In the polyether polycarbonate diol (A), the carbonate compound used as a raw material at the time of production may remain. The residual amount of the carbonate compound in the polyether polycarbonate diol (A) is not limited, but it is preferably small, and the upper limit of the weight ratio to the polycarbonate diol (A) is preferably 5% by weight, more preferably 3% by weight. , More preferably 1% by weight. If the content of the carbonate compound of the polyether polycarbonate diol (A) is too large, the reaction during polyurethane formation may be hindered. On the other hand, the lower limit thereof is not particularly limited, but is preferably 0.1% by weight, more preferably 0.01% by weight, and even more preferably 0% by weight.

The polyoxyalkylene glycol used in the production may remain in the polyether polycarbonate diol (A). The residual amount of the polyoxyalkylene glycol in the polyether polycarbonate diol (A) is not limited, but is preferably small, and the weight ratio to the polyether polycarbonate diol (A) is preferably 1% by weight or less, more preferably. Is 0.1% by weight or less, more preferably 0.05% by weight or less. If the residual amount of polyoxyalkylene glycol in the polyether polycarbonate diol (A) is large, the molecular length of the soft segment site when polyurethane is used may be insufficient, and desired physical properties may not be obtained.

The lower limit of the hydroxyl value of the polyether polycarbonate diol (A) is usually 22.4 mg-KOH / g, preferably 28.1 mg-KOH / g, more preferably 37.4 mg-KOH / g, and the upper limit is usually 187.0 mg. -KOH / g, preferably 140.3 mg-KOH / g, more preferably 124.7 mg-KOH / g. If the hydroxyl value is less than the above lower limit, the viscosity may become too high and handling at the time of polyurethane formation may be difficult, and if the above upper limit is exceeded, the flexibility of the obtained polyurethane for synthetic leather may be insufficient.
Specifically, the hydroxyl value of the polyether polycarbonate diol (A) is measured by the method described in the section of Examples described later.

The lower limit of the number average molecular weight (Mn) determined from the hydroxyl value of the polyether polycarbonate diol (A) used in the present invention is 600, preferably 800, more preferably 1000, and even more preferably 1500. On the other hand, the upper limit is preferably 5,000, more preferably 4,000, and even more preferably 3,000. If the Mn of the polyether polycarbonate diol (A) is less than the above lower limit, sufficient flexibility may not be obtained when polyurethane for synthetic leather is used. On the other hand, if the above upper limit is exceeded, the viscosity increases, which may impair the handling during polyurethane formation.

<(A) / Isocyanate ratio>
The ratio of the structural unit derived from the polyether polycarbonate diol (A) to the structural unit derived from the polyisocyanate compound contained in the polyurethane for synthetic leather of the present invention (hereinafter, may be referred to as "(A) / isocyanate ratio"). ) Is preferably 20 to 60 mol%, more preferably 25 to 55 mol%. When the (A) / isocyanate ratio is within the above range, the polyurethane of the present invention contains a structural unit derived from the polyether polycarbonate diol (A), which has an effect of improving flexibility, flexibility and chemical resistance at low temperatures. Can be sufficiently obtained, which is preferable.
The (A) / isocyanate ratio of the polyurethane of the present invention can be measured by the method described in the section of Examples described later.

<Molecular weight>
The molecular weight of the polyurethane for synthetic leather of the present invention is appropriately adjusted according to its use, and is not particularly limited, but the polystyrene-equivalent weight average molecular weight (Mw) measured by GPC may be 50,000 to 500,000. It is preferably 100,000 to 300,000, more preferably 100,000 to 300,000. If Mw is smaller than the above lower limit, sufficient strength and hardness may not be obtained, and if it is larger than the above upper limit, handleability such as workability tends to be impaired.

[Manufacturing method of polyurethane for synthetic leather]
The polyurethane for synthetic leather of the present invention can be produced by a usual polyurethane-forming reaction except that a polyether polycarbonate diol (A), a polyisocyanate compound and the above-mentioned chain extender are used. At this time, the usage amount ratio of the polyether polycarbonate diol (A) and the polyisocyanate compound is preferably adjusted so that the above-mentioned polyether polycarbonate diol (A) unit / polyisocyanate compound unit molar ratio can be obtained.

As an example of the production of the polyurethane for synthetic leather of the present invention, a polyol other than the polyether polycarbonate diol (A) and the polyether polycarbonate diol (A) used as needed (hereinafter, may be referred to as "other polyol"). ), A method in which a polyisocyanate compound and a chain extender are mixed and reacted in a batch (hereinafter, may be referred to as a "one-step method"), or firstly used with a polyether polycarbonate diol (A) as necessary. After preparing a prepolymer having isocyanate groups at both ends by reacting the polyol and the polyisocyanate compound of the above, a method of reacting the prepolymer with a chain extender (hereinafter, may be referred to as a "two-step method") or the like. is there.

In the two-step method, the polyether polycarbonate diol (A) and other polyols used as needed are reacted with 1 equivalent or more of the polyisocyanate compound in advance, so that both terminal isocyanates of the portion corresponding to the soft segment of polyurethane are obtained. It goes through the process of preparing an intermediate. As described above, when the prepolymer is once prepared and then reacted with the chain extender, it may be easy to adjust the molecular weight of the soft segment portion, and when it is necessary to reliably perform phase separation between the soft segment and the hard segment. Is useful.

<Chain terminator>
When producing the polyurethane for synthetic leather of the present invention, a chain terminator having one active hydrogen group can be used, if necessary, for the purpose of controlling the molecular weight of the obtained polyurethane.

Examples of these chain terminators include aliphatic monools such as methanol, ethanol, propanol, butanol, and hexanol having one hydroxyl group, diethylamine, dibutylamine, n-butylamine, monoethanolamine, and diethanolamine having one amino group. , Morpholine and other aliphatic monoamines are exemplified.
These may be used alone or in combination of two or more.

<Catalyst>
In the polyurethane forming reaction in producing the polyurethane for synthetic leather of the present invention, amines such as triethylamine, N-ethylmorpholin, triethylenediamine, diazabicycloundecene, and 1,4-diazabicyclo [2.2.2] octane System catalysts or acid catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and sulfonic acid, tin compounds such as trimethyltin laurate, dibutyltin dilaurate, dioctyltin dilaurate, and dioctyltin dineodecanetes, and titanium compounds. A known urethane polymerization catalyst typified by an organic metal salt such as, etc. can also be used. One type of urethane polymerization catalyst may be used alone, or two or more types may be used in combination.

<Other polyols>
When producing the polyurethane for synthetic leather of the present invention, other polyols other than the polyether polycarbonate diol (A) may be used in combination, if necessary. Here, the other polyol is not particularly limited as long as it is used in the production of ordinary polyurethane, and examples thereof include a polyether polyol, a polyester polyol, a polycaprolactone polyol, and a polycarbonate polyol. For example, when the polyether polycarbonate diol (A) and the polyether polyol are used in combination, a polyurethane having further improved low temperature characteristics, which is a characteristic of the polyether polycarbonate diol (A), can be obtained.
When other polyols are used in combination, the weight ratio of the polyether polycarbonate diol (A) to the combined weight of the polyether polycarbonate diol (A) and the other polyol is preferably 50% or more, more preferably 70% or more. If the weight ratio of the polyether polycarbonate diol (A) is small, the physical balance of chemical resistance, flexibility at low temperature, and flexibility, which are the characteristics of the present invention, may be lost.

<One-step method>
The one-step method is also called a one-shot method, and is a method in which a reaction is carried out by collectively charging a polyether polycarbonate diol (A) with another polyol, a polyisocyanate compound, and a chain extender used as needed. ..

The amount of the polyisocyanate compound used in the one-step method is not particularly limited, but is 1 equivalent of the total number of hydroxyl groups of the polyether polycarbonate diol (A) and other polyols, and the total number of hydroxyl groups and amino groups of the chain extender. If so, the lower limit is preferably 0.7 equivalents, more preferably 0.8 equivalents, still more preferably 0.9 equivalents, particularly preferably 0.95 equivalents, and the upper limit is preferably 3.0 equivalents. It is more preferably 2.0 equivalents, even more preferably 1.5 equivalents, and particularly preferably 1.1 equivalents.

If the amount of the polyisocyanate compound used is too large, unreacted isocyanate groups cause a side reaction, and the viscosity of the obtained polyurethane tends to be too high, making it difficult to handle or impairing flexibility. If it is too small, the molecular weight of polyurethane will not be sufficiently large, and there is a tendency that sufficient polyurethane strength cannot be obtained.

The amount of the chain extender used is not particularly limited, but when the number obtained by subtracting the number of isocyanate groups of the polyisocyanate compound from the total number of hydroxyl groups of the polyether polycarbonate diol (A) and other polyols is set to 1 equivalent, the lower limit is set to 1 equivalent. , Preferably 0.7 equivalents, more preferably 0.8 equivalents, even more preferably 0.9 equivalents, particularly preferably 0.95 equivalents, with an upper limit of preferably 3.0 equivalents, more preferably 2.0 equivalents. , More preferably 1.5 equivalents, and particularly preferably 1.1 equivalents. If the amount of the chain extender used is too large, the obtained polyurethane tends to be difficult to dissolve in the solvent and it tends to be difficult to process, and if it is too small, the obtained polyurethane is too soft and has sufficient strength and hardness, elastic recovery performance and elasticity. Retention performance may not be obtained or heat resistance may deteriorate.

<Two-step method>
The two-step method is also called a prepolymer method, and there are mainly the following methods.
(I) Reaction of a polyisocyanate compound / (polyether polycarbonate diol (A) and other polyol) with an excess polyisocyanate compound and a polyether polycarbonate diol (A) and other polyols used as necessary in advance. A method for producing a polyurethane having a prepolymer having an isocyanate group at the end of the molecular chain by reacting from an amount having an equivalent ratio of more than 1 to 10.0 or less, and then adding a chain extender to the prepolymer (ii). The reaction equivalent ratio of the polyisocyanate compound / (polyether polycarbonate diol (A) and other polyol) to the excess polyether polycarbonate diol (A) and other polyol used as needed is 0. A method for producing a polyurethane by reacting it from 1 or more to less than 1.0 to produce a prepolymer having a hydroxyl group at the end of the molecular chain, and then reacting it with a polyisocyanate having an isocyanate group at the end as a chain extender.

The two-step method can be carried out in the absence of a solvent or in the presence of a solvent.

Polyurethane production by the two-step method can be performed by any of the methods (1) to (3) described below.
(1) A prepolymer is synthesized by directly reacting a polyisocyanate compound, a polyether polycarbonate diol (A), and another polyol without using a solvent, and is used as it is for a chain extension reaction.
(2) The prepolymer is synthesized by the method of (1), then dissolved in a solvent, and used for the subsequent chain extension reaction.
(3) Using a solvent from the beginning, the polyisocyanate compound, the polyether polycarbonate diol (A) and other polyol are reacted, and then a chain extension reaction is carried out.

In the case of the method (1), in the chain extension reaction, the polyurethane is obtained in the form of coexisting with the solvent by a method such as dissolving the chain extender in a solvent or simultaneously dissolving the prepolymer and the chain extender in the solvent. This is very important.

The amount of the polyisocyanate compound used in the two-step method (i) is not particularly limited, but the number of isocyanate groups when the total number of hydroxyl groups of the polyether polycarbonate diol (A) and other polyols is 1 equivalent. The lower limit is preferably an amount exceeding 1.0 equivalent, more preferably 1.2 equivalent, further preferably 1.5 equivalent, and the upper limit is preferably 10.0 equivalent, more preferably 5.0 equivalent, and further. It is preferably in the range of 3.0 equivalents.

If the amount of this polyisocyanate compound used is too large, excess isocyanate groups tend to cause side reactions and it is difficult to reach the desired physical properties of the polyurethane, and if it is too small, the molecular weight of the obtained polyurethane does not increase sufficiently and the strength is increased. And thermal stability may be low.

The amount of the chain extender used is not particularly limited, but the lower limit is preferably 0.1 equivalent, more preferably 0.5 equivalent, and even more preferably 0. It is 8 equivalents, with an upper limit preferably in the range of 5.0 equivalents, more preferably 3.0 equivalents, and even more preferably 2.0 equivalents.

When the chain extension reaction is carried out, monofunctional organic amines and alcohols may coexist for the purpose of adjusting the molecular weight.

The amount of the polyisocyanate compound used in producing the prepolymer having a hydroxyl group at the end in the two-step method (ii) is not particularly limited, but is the total of the polyether polycarbonate diol (A) and other polyols. When the number of hydroxyl groups is 1 equivalent, the lower limit is preferably 0.1 equivalent, more preferably 0.5 equivalent, still more preferably 0.7 equivalent, and the upper limit is preferably 0.99. Equivalent, more preferably 0.98 equivalent, even more preferably 0.97 equivalent.

If the amount of this polyisocyanate compound used is too small, the process until the desired molecular weight is obtained in the subsequent chain extension reaction tends to be long, and the production efficiency tends to decrease. If the amount is too large, the viscosity of the obtained polyurethane becomes too high. Flexibility may be reduced, handling may be poor, and productivity may be poor.

The amount of the chain extender used is not particularly limited, but when the total number of hydroxyl groups of the polyether polycarbonate diol (A) used in the prepolymer and other polyols is 1 equivalent, the equivalent of the isocyanate group used in the prepolymer is used. The lower limit is preferably 0.7 equivalents, more preferably 0.8 equivalents, still more preferably 0.9 equivalents, and the upper limit is preferably less than 1.0 equivalents, more preferably 0.99 equivalents. It is in the range of equivalents, more preferably 0.98 equivalents.

When the chain extension reaction is carried out, monofunctional organic amines and alcohols may coexist for the purpose of adjusting the molecular weight.

The chain extension reaction is usually carried out at 0 ° C. to 250 ° C., but this temperature varies depending on the amount of solvent, reactivity of raw materials used, reaction equipment and the like, and is not particularly limited. If the temperature is too low, the reaction may proceed too slowly, or the solubility of the raw material or polymer may be low, resulting in a long production time. If the temperature is too high, side reactions or decomposition of the obtained polyurethane may occur. .. The chain extension reaction may be carried out while defoaming under reduced pressure.

Further, a catalyst, a stabilizer, or the like can be added to the chain extension reaction, if necessary.
Examples of the catalyst include amine-based catalysts such as triethylamine, tributylamine, N-ethylmorpholine and triethylenediamine, acid-based catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid and sulfonic acid, trimethyltin laurate, dibutyltin dilaurate and dioctyltin. Known urethane polymerization catalysts typified by tin-based compounds such as dilaurate and dioctyltin dineodecanete, and organic metal salts such as titanium-based compounds can be used. One type of urethane polymerization catalyst may be used alone, or two or more types may be used in combination.
Stabilizers include, for example, 2,6-dibutyl-4-methylphenol, distearylthiodipropionate, N, N'-di-2-naphthyl-1,4-phenylenediamine, tris (dinonylphenyl) phos. Examples include compounds such as Phenol, and one type may be used alone, or two or more types may be used in combination.
If the chain extender is a highly reactive one such as a short-chain aliphatic amine, it may be carried out without adding a catalyst.

<Additives>
The polyurethane for synthetic leather of the present invention includes heat stabilizers, light stabilizers, colorants, fillers, stabilizers, ultraviolet absorbers, antioxidants, anti-adhesive agents, flame retardants, anti-aging agents, inorganic fillers and the like. Various additives can be added and mixed as long as the characteristics of the polyurethane of the present invention are not impaired.

Compounds that can be used as heat stabilizers include phosphoric acid, aliphatic, aromatic or alkyl group-substituted aromatic esters of phosphoric acid, hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, and poly. Phosphonates, dialkylpentaerythritol diphosphite, dialkylbisphenol A diphosphite and other phosphorus compounds; phenolic derivatives, especially hindered phenol compounds; thioethers, dithioates, mercaptobenzimidazoles, thiocarbanilides, thiodipropionic acid esters Sulfur-containing compounds such as those used; tin compounds such as sumalate and dibutyltin monooxide can be used.

Specific examples of the hindered phenol compound include "Irganox 1010" (trade name: manufactured by BASF Japan Ltd.), "Irganox 1520" (trade name: manufactured by BASF Japan Ltd.), and "Irganox 245" (trade name: manufactured by BASF Japan Ltd.). )
And so on.
Examples of phosphorus compounds include "PEP-36", "PEP-24G", "HP-10" (trade name: manufactured by ADEKA Corporation), "Irgafos 168" (trade name: manufactured by BASF Japan Ltd.), etc. Can be mentioned.

Specific examples of the sulfur-containing compound include thioether compounds such as dilauryl thiopropionate (DLTP) and distearyl thiopropionate (DSTP).

Examples of the light stabilizer include benzotriazole-based and benzophenone-based compounds, and specifically, "TINUVIN622LD", "TINUVIN765" (all manufactured by Ciba Specialty Chemicals Co., Ltd.), "SANOL LS-2626". , "SANOL LS-765" (all manufactured by Sankyo Co., Ltd.) and the like can be used.

Examples of the ultraviolet absorber include "TINUVIN328" and "TINUVIN234" (all manufactured by Ciba Specialty Chemicals Co., Ltd.).

Coloring agents include direct dyes, acidic dyes, basic dyes, metal complex salt dyes and other dyes; inorganic pigments such as carbon black, titanium oxide, zinc oxide, iron oxide and mica; and coupling azo and condensed azo dyes. Examples thereof include organic pigments such as anthraquinone-based, thioindigo-based, dioxazone-based, and phthalocyanine-based.

Examples of the inorganic filler include short glass fibers, carbon fibers, alumina, talc, graphite, melamine, and white clay.

Examples of the flame retardant include phosphorus-containing organic compounds, halogen-containing organic compounds such as bromine and chlorine, addition of ammonium polyphosphate, aluminum hydroxide, antimony oxide and the like, and reactive flame retardants.

These additives may be used alone or in combination of two or more in any combination and ratio.

The lower limit of the amount of these additives added to the polyurethane is preferably 0.01% by weight, more preferably 0.05% by weight, further preferably 0.1% by weight, and the upper limit is preferably 10% by weight. %, More preferably 5% by weight, even more preferably 1% by weight. If the amount of the additive added is too small, the effect of the addition cannot be sufficiently obtained, and if it is too large, it may precipitate in the polyurethane or cause turbidity.

[Synthetic leather]
As a method for producing synthetic leather using the polyurethane for synthetic leather of the present invention, a known method can be used, for example, as shown in "Artificial Leather / Synthetic Leather Japan Textile Consumption Science Society (2010)". Manufactured by the method. In general, synthetic leather indicates a woven fabric or knitted fabric as a base material, and may be distinguished as a component different from artificial leather using a non-woven fabric as a base material. However, in recent years, the distinction has become less strict, such as attaching woven or knitted fabrics to impart strength to the non-woven fabric. The polyurethane for synthetic leather in the present invention can be equally applied to polyurethane for artificial leather, and also includes a composition that distinguishes between synthetic leather and artificial leather, and the effects of the present invention are exhibited in both cases. To do.

In the synthetic leather using the polyurethane for synthetic leather of the present invention, for example, a microporous layer containing a polyurethane resin is formed on a base cloth as a base material, and a polyurethane resin for a skin layer is laminated via an adhesive layer. It is manufactured by containing a polyurethane resin on a base material filled with a resin such as polyurethane, or by laminating a microporous layer on the polyurethane resin. The polyurethane of the present invention may be applied or impregnated into the above-mentioned base material, contained in an adhesive layer, used as an epidermis layer, or used in other layers.

Examples of the embodiment of the synthetic leather using the polyurethane for synthetic leather of the present invention include the following synthetic leather laminates (1) or (2).
(1) Synthetic leather laminate in which the base cloth, the adhesive layer, the intermediate layer, and the skin layer containing the polyurethane for synthetic leather of the present invention are laminated in this order (2) The base cloth, the adhesive layer, and the book Synthetic leather laminate in which the intermediate layer containing the polyurethane for synthetic leather of the present invention and the epidermis layer are laminated in this order.

<Base material>
As the base material, a base cloth can be used, and specifically, synthetic fibers such as polyester, polyamide, polyacrylonitrile, polyolefin and polyvinyl alcohol, natural fibers such as cotton and hemp, and recycled rayon, sufu and acetate. Knitted fabrics, woven fabrics, non-woven fabrics, etc., which consist of single or blended fibers such as fibers, or multi-component fibers modified into ultrafine fibers by dissolving at least one component or dividing two-component fibers. Can be used.
This base cloth may be brushed. The brushing may be single-sided brushing or double-sided brushing. Further, the base cloth may have a multi-layer structure composed of a plurality of fibers as well as a single layer. Further, as the base cloth, a knitted fabric having a raised surface may be used.

<Microporous layer>
The base material may have a microporous layer. The wet microporous layer is produced by a general base fabric impregnation method. For example, the base cloth is immersed in the dimethylformamide solution containing the polyurethane of the present invention, or the solution is applied to the base cloth, coagulated and desolvated in water, dehydrated, and then dried under hot air at about 120 ° C. Therefore, a wet microporous layer having excellent surface smoothness can be formed.
The thickness of the wet microporous layer is preferably 50 to 400 μm, more preferably 100 to 300 μm. Optimal flexibility and volume as synthetic leather are achieved within this thickness range.

<Adhesive layer>
When the skin layer is bonded to the base material via an adhesive, a conventional adhesive such as a polyurethane resin, an acrylic resin, or an epoxy resin can be used as the adhesive used for the adhesive layer. The polyurethane of the present invention can also be used for the adhesive layer. A cross-linking agent and, if necessary, a cross-linking accelerator may be added to the adhesive used for this adhesive layer.

<Middle layer>
The intermediate layer can be appropriately set in consideration of the texture of the obtained synthetic leather, the intended use, and the like. The intermediate layer is formed of, for example, a polyurethane resin having a terminal isocyanate group and a compounding solution for a foamed layer containing water. The polyurethane resin having a terminal isocyanate group can be obtained by reacting, for example, diphenylmethane diisocyanate (MDI) as a polyisocyanate component and, for example, a polycarbonate polyol, a polyether polyol, or the like as a polyol component. The compounding solution for the intermediate layer constituting the intermediate layer may contain, for example, a foam stabilizer, a foaming catalyst, a foaming nucleating agent, and the like, if necessary. The polyurethane of the present invention can also be used for the intermediate layer.

<Epidermis layer>
The polyurethane of the present invention can also be used for the epidermis layer. In this case, the polyurethane of the present invention may be used as it is for the skin layer, or the polyurethane of the present invention is mixed with other resins, antioxidants, ultraviolet absorbers, etc. to prepare a polyurethane solution, which is then mixed with a colorant and a colorant. It may be formed by using a skin layer compounding solution obtained by mixing an organic solvent or the like. In addition, if necessary, an antioxidant, a pigment, a dye, a flame retardant, a filler, a cross-linking agent and the like can be added to the polyurethane solution.

Examples of other resins include polyurethanes other than the polyurethane of the present invention, poly (meth) acrylic resins, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl propionate copolymers, polyvinyl butyral resins, and fibers. Examples thereof include elementary resins, polyester resins, epoxy resins and phenoxy resins, and polyamide resins.

Examples of the cross-linking agent include organic polyisocyanate, crude MDI, TDI adduct of trimethylolpropane, and polyisocyanate compounds such as triphenylmethane triisocyanate.

The epidermis layer can be formed into a desired thickness by applying the epidermis layer compounding solution containing the polyurethane of the present invention onto the release material and heating and drying. After that, an adhesive is further applied to form an adhesive layer, a base cloth such as a brushed cloth is laminated on the base cloth and dried, and after aging at room temperature for several days, the release material is peeled off to obtain synthetic leather. Be done.

In the present invention, the artificial leather or synthetic leather produced in this manner may be kneaded and wrinkled with a liquid flow dyeing machine or the like to form natural leather-like wrinkles.

<Use>
The artificial leather or synthetic leather using the polyurethane for synthetic leather of the present invention can be used for automobile interior materials, furniture, clothing, shoes, bags and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded.

〔Evaluation methods〕
The evaluation methods of the polyether polycarbonate diol, the polycarbonate diol, the polyalkylene ether glycol and the like used in the following examples and comparative examples are as follows.

[Evaluation method of polyether polycarbonate diol, polycarbonate diol, polyalkylene ether glycol]
<Hydroxy group value / number average molecular weight>
The hydroxyl values of the polycarbonate diol and the polyalkylene ether glycol were measured by a method using an acetylation reagent according to JIS K1557-1. In addition, the hydroxyl value of polyether polycarbonate diol is according to the American Materials Testing Association (ASTM), the hydroxyl group is urethanized with p-toluenesulfonyl isocyanate as a tetrahydrofuran solution, and the excess urethanization reagent is hydrolyzed with water to sample the hydroxyl group. The sulfonylamide ester produced from the above was determined by hydrolysis with a base.
From the obtained hydroxyl value, the number average molecular weight (Mn) was determined by the following formula (I).
Number average molecular weight = 2 × 56.1 / (hydroxyl value × 10 ^-3 )… (I)

[Evaluation method of polyurethane]
<Molecular weight>
Polyurethane was dissolved in dimethylacetamide to prepare a dimethylacetamide solution so that the concentration was 0.14% by weight. Using a GPC device [manufactured by Tosoh Corporation, product name "HLC-8220" (column: Tskgel GMH-XL, 2 bottles)], the dimethylacetamide solution was injected, and the weight average molecular weight (Mw) of polyurethane was converted into standard polystyrene. Was measured.

<(A) / Isocyanate ratio>
Polyurethane _{was dissolved in CDCl 3} , and 400 MHz ¹ H-NMR (AL-400 manufactured by JEOL Ltd.) was measured, and the (A) / isocyanate ratio (mol%) was determined from the signal position of each component.

<Tensile test>
A 3 cm x 3 cm test piece is cut out from the polyurethane film, and the test piece is chucked using a tensile tester (manufactured by Orientec, product name "Tencilon UTM-III-100") according to JIS K6301 (2010). A tensile test was carried out at a distance of 50 mm, a tensile speed of 500 mm / min, a temperature condition of 23 ° C. or -10 ° C., and a relative humidity of 55%. It was measured. Those having a 100% modulus of 5 MPa or less are excellent in flexibility, and the lower the ratio of the 100% modulus measured under the -10 ° C condition to the 100% modulus measured under the 23 ° C condition, the smaller the change in strength due to temperature. Delamination of the synthetic leather laminate can be suppressed. The ratio of 100% modulus measured under the condition of −10 ° C. to 100% modulus measured under the condition of 23 ° C. is preferably 1.8 or less, more preferably 1.5 or less. In addition, the elongation and strength when the test piece broke were also measured. The higher the elongation and the higher the strength, the better the flexibility and mechanical strength.

<Olein resistant acidity>
A 3 cm × 3 cm test piece was cut out from the polyurethane film, and the test piece was placed in a glass bottle having a capacity of 50 ml containing 10 ml of oleic acid as a test solvent, and allowed to stand at 80 ° C. for 18 hours. After the test, the test piece was taken out and lightly wiped with a paper wiper, and then the weight was measured with a precision balance to calculate the weight change rate (increase rate) from before the test. When the weight change rate is close to 0%, the olein acid resistance is good.

[Manufacturing and evaluation of polyether polycarbonate diol]
The following abbreviations were used for the compounds described in Synthesis Examples, Examples and Comparative Examples.
PEPCD: Polyether Polycarbonate Diol PTMG: Polytetramethylene Ether Glycol EC: Ethylene Carbonate EG: Ethylene Glycol Mg (acac) ₂ : Magnesium (II) Acetylacetonate BG: 1,4-Butanediol MDI: 4,4'-Diphenylmethane Diisocyanate PTMG # 250: Polytetramethylene ether glycol manufactured by Mitsubishi Chemical Co., Ltd., which has a hydroxyl value-based number average molecular weight (Mn) of 250 PTMG # 650: Mitsubishi Chemical Co., Ltd., which has a hydroxyl value-based number average molecular weight (Mn) of 650. Company-made polytetramethylene ether glycol

[Synthesis Example 1]
_{Put PTMG # 250: 515 g, EC: 285 g, Mg (acac) 2} : 0.25 g in a 1 L glass 4-neck flask (flask) equipped with a magnetic stir bar, distillate trap, pressure regulator and 400 mm Vigreux tube. , The inside of the flask was replaced with nitrogen gas. Under stirring, the internal temperature was raised to 150 ° C. to dissolve the contents. Then, after reacting at normal pressure for 2 hours, the pressure was lowered to 8 to 4 kPa, and the reaction was carried out for 12 hours while removing EG and EC from the system. Next, 37 g of EC (hereinafter referred to as “EC (additional 1)”) was added, the pressure was lowered to 4 to 2 kPa, and the reaction was carried out at 150 ° C. for 8 hours. Further, EC (hereinafter referred to as "EC (additional 2)"): 37 g was added, and the reaction was continued for 10 hours.
Then, an 8.5% aqueous phosphoric acid solution (1.1 mL) was added to the reaction product in the flask to inactivate the catalyst. Then, the Vigreux tube was removed, and the residual monomer was removed at 168 to 178 ° C. at 0.3 kPa or less.

The reaction product in the flask from which the residual monomer was removed was sent to a thin film distillation apparatus at a flow rate of 20 g / min, and thin film distillation (temperature: 210 ° C., pressure: 53 Pa) was performed to obtain PEPCD. As the thin film distillation apparatus, an internal condenser having a diameter of 50 mm, a height of 200 mm, and an area of 0.0314 m ^{2 and} a special molecular distillation apparatus MS-300 manufactured by Shibata Scientific Technology Co., Ltd. with a jacket were used.
The PEPCD produced in Synthesis Example 1 is referred to as "PEPCD1". Table 1 shows the properties of PEPCD1 and the number average molecular weight based on the hydroxyl value.

[Synthesis Example 2]
PEPCD was obtained in the same manner as in Synthesis Example 1 except that PTMG # 650 was used instead of PTMG # 250 and the amounts were changed to those shown in Table 1. The PEPCD produced in Synthesis Example 2 is referred to as "PEPCD2". Table 1 shows the properties of PEPCD2 and the evaluation results of the physical properties.

[Manufacturing and evaluation of polyurethane]
[Example 1]
<Manufacturing of polyurethane>
Using PEPCD2 obtained in Synthesis Example 2 as a raw material, polyurethane was produced by the following operation.
(Prepolymer (PP) conversion reaction)
A separable flask equipped with a thermocouple, a cooling tube and a stirrer was installed on an oil bath at 60 ° C., 49.6 g of PEPCD2 preheated to 80 ° C. was added, and then 4,4'-dicyclohexylmethane diisocyanate was added. (Hereinafter referred to as "H12MDI") 13.15 g and 0.23 g of triisooctylphosphite (hereinafter referred to as "TiOP") as a reaction inhibitor were added to the inside of the separable flask. The temperature was raised to 80 ° C. in about 1 hour while stirring at 60 rpm in a nitrogen atmosphere. After reaching 80 ° C., Neostan U-830 (hereinafter sometimes referred to as "U-830"; manufactured by Nitto Kasei Co., Ltd.) 0.0031 g (50 wt ppm based on the total weight of PEPCD2 and H12MDI) as a urethanization catalyst. Was added to the separable flask, the temperature of the oil bath was raised to 100 ° C. after the heat generation had subsided, and the mixture was further stirred for about 2 hours. The concentration of isocyanate groups was analyzed, and it was confirmed that the theoretical amount of isocyanate groups was consumed, and a prepolymer was obtained.

(Chain extension reaction)
63.0 g of the obtained prepolymer (hereinafter sometimes referred to as "PP") is dehydrated N, N-dimethylformamide (hereinafter sometimes referred to as "DMF"; manufactured by Wako Pure Chemical Industries, Ltd.) at 146.92 g. Diluted. The temperature of the oil bath was set to 55 ° C., and PP was dissolved while stirring at about 200 rpm to prepare a solution of PP. Next, the temperature of the oil bath was set to 35 ° C., the mixture was stirred at 150 rpm, and the isocyanate group concentration in the PP solution was analyzed. 3.48 g of isophorone diamine (hereinafter, may be abbreviated as "IPDA", manufactured by Tokyo Chemical Industry Co., Ltd.) calculated from the amount of isocyanate remaining by the analysis was added in portions. After the divided addition, the mixture was stirred for about 1 hour, and 0.18 g of morpholin (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a chain terminator. After the addition of morpholin, the mixture was further stirred for 1 hour to obtain a polyurethane having a weight average molecular weight of 147,500. Table 2 shows the properties of the obtained polyurethane and the evaluation results of the physical properties.

[Comparative Example 1]
Polyurethane was obtained in the same manner as in Example 1 except that T6002 was used instead of PEPCD2 and the amount was changed to the amount shown in Table 2. Table 2 shows the properties of the obtained polyurethane and the evaluation results of the physical properties.
Note that T6002 is a polycarbonate diol manufactured by Asahi Kasei Corporation, which has only a structural unit derived from 1,6-hexanediol and has a number average molecular weight (Mn) of 2000 based on the hydroxyl value.

[Comparative Example 2]
Polyurethane was obtained in the same manner as in Example 1 except that PTMG # 2000 was used instead of PEPCD2 and the amount was changed to the amount shown in Table 2. Table 2 shows the properties of the obtained polyurethane and the evaluation results of the physical properties.
Note that PTMG # 2000 is a polytetramethylene ether glycol manufactured by Mitsubishi Chemical Corporation, which has a number average molecular weight (Mn) of 2000 based on the hydroxyl value.

[Example 2]
<Manufacturing of polyurethane>
Using PEPCD1 obtained in Synthesis Example 1 as a raw material, polyurethane was produced by the following operation.
A separable flask equipped with a thermocouple, a cooling tube and a stirrer was installed on an oil bath at 60 ° C., and 50.56 g of PEPCD1 preheated to 80 ° C., 4.9 g of BG, and dehydrated N, N- 176.64 g of dimethylformamide (hereinafter sometimes abbreviated as "DMF"; manufactured by Wako Pure Chemical Industries, Ltd.) is added, and then 4,4'-diphenylmethanediisocyanate (hereinafter sometimes referred to as "MDI") 14 .57 g was added, and the temperature inside the separable flask was raised to 80 ° C. in about 1 hour while stirring at 60 rpm in a nitrogen atmosphere. After reaching 80 ° C., 0.0136 g of Neostan U-830 (hereinafter sometimes referred to as “U-830”, manufactured by Nitto Kasei Co., Ltd.) was added as a urethanization catalyst, and the mixture was further stirred at 80 ° C. for about 2 hours. did. Then, MDI was added in portions to adjust the molecular weight to obtain polyurethane having a molecular weight of 1524,000. Table 3 shows the properties of this polyurethane and the evaluation results of the physical properties.

[Example 3]
Polyurethane was obtained in the same manner as in Example 2 except that PEPCD2 was used instead of PEPCD1 and the amount was changed to the amount shown in Table 3. Table 3 shows the properties of the obtained polyurethane and the evaluation results of the physical properties.

[Comparative Example 3]
Polyurethane was obtained in the same manner as in Example 2 except that T6002 was used instead of PEPCD1 and the amount was changed to the amount shown in Table 3. Table 3 shows the properties of the obtained polyurethane and the evaluation results of the physical properties.

The following can be seen from Tables 2 and 3.
The polyurethane described in the examples containing a specific structural unit is clearly excellent in low temperature flexibility because of its low modulus at −10 ° C., and is useful for synthetic leather.
On the other hand, the polyurethane described in Comparative Example, for example, a polyurethane having a structural unit derived from polycarbonate diol, has a high modulus at −10 ° C. and is inferior in low temperature flexibility. Further, the chemical resistance of polyurethane having a structural unit derived from polytetramethylene ether glycol is extremely deteriorated.

Claims (10)

Obtained from the structural unit derived from a compound having a plurality of isocyanate groups, the structural unit derived from at least one compound selected from the group consisting of polyols and polyamines, and the hydroxyl value represented by the following formula (A). Polyurethane for synthetic leather containing a structural unit derived from a polyether polycarbonate diol having a number average molecular weight of 600 or more.

(In the above formula (A), R represents a divalent hydrocarbon group having 2 to 10 carbon atoms, n is an integer of 2 to 30, and m is an integer of 1 to 20. ), Multiple Rs may be the same or different.) The polyurethane for synthetic leather according to claim 1, wherein R in the formula (A) is an n-butylene group. The polyurethane for synthetic leather according to claim 1 or 2, wherein n in the formula (A) is an integer of 2 to 20. The polyurethane for synthetic leather according to any one of claims 1 to 3, wherein m in the formula (A) is an integer of 4 to 20. Any one of claims 1 to 4, wherein the at least one compound selected from the group consisting of the polyol and the polyamine is at least one compound selected from the group consisting of ethylenediamine, isophoronediamine and hexamethylenediamine. Polyurethane for synthetic leather described in. At least one compound selected from the group consisting of the polyol and polyamine is at least one compound selected from the group consisting of 1,4-butanediol, ethylene glycol, propylene glycol and 1,6-hexanediol. The polyurethane for synthetic leather according to any one of claims 1 to 4. Any of claims 1 to 6, wherein the compound having a plurality of isocyanate groups is at least one compound selected from the group consisting of 4,4'-dicyclohexylmethane diisocyanate, 1,6-hexamethylene diisocyanate and isophorone diisocyanate. The polyurethane for synthetic leather according to item 1. Any of claims 1 to 7, wherein the ratio of the structural unit derived from the polyether polycarbonate diol represented by the formula (A) to the structural unit derived from the compound having a plurality of isocyanate groups is 20 to 60 mol%. The polyurethane for synthetic leather according to item 1. A synthetic leather laminate in which a base cloth, an adhesive layer, an intermediate layer, and a skin layer containing the polyurethane for synthetic leather according to any one of claims 1 to 8 are laminated in this order. A synthetic leather laminate in which a base cloth, an adhesive layer, an intermediate layer containing the polyurethane for synthetic leather according to any one of claims 1 to 8, and an epidermis layer are laminated in this order.