JP2014105250A - Urethane prepolymer composition, two liquid-type coating agent and synthetic imitation leather using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environment-responsive urethane prepolymer composition used by reacting an active hydrogen in its component with a crosslinking agent to achieve higher molecular weight, having little restriction of usable life with a liquid state from 30°C with no solvent without using an organic solvent and water, hardly generating release of a volatile organic substance to atmosphere, and to provide a two liquid-type coating agent and a synthetic imitation leather using the same.SOLUTION: There is provided an urethane prepolymer composition which is used by reacting an active hydrogen in its component with a crosslinking agent to achieve higher molecular weight, containing 20 to 80 mass% of a hydroxyl group terminal urethane prepolymer having the hydroxyl value of 10 to 100 mgKOH/g and further containing 20 to 80 mass% of an oligomer, as a medium of the polymer, having no urethane bound and having the hydroxyl value of 20 to 400 mgKOH/g capable of crosslinking with the crosslinking agent, substantially having nonvolatile content of 100%, and being in a liquid state at least at a temperature of 30°C.

Description

  The present invention relates to a urethane prepolymer composition, a two-component coating agent comprising the composition and a polyisocyanate cross-linking agent, and a synthetic artificial leather using the coating agent. More specifically, a urethane prepolymer composition having a substantially non-volatile content of 100%, which does not use an organic solvent, has a large influence on the environment, a two-component coating agent using the composition, and the coating agent. It relates to the synthetic artificial leather used. In the present invention, the synthetic artificial leather is any one of artificial leather, synthetic leather, and leather.

  Conventionally, as an environmentally-friendly urethane resin, for example, an aqueous type (see Patent Document 1), a TPU (thermoplastic polyurethane resin elastomer) type, a moisture-curing hot melt type (see Patent Document 2), an NCO-based block, and the like A type (see Patent Document 3), an ultraviolet ray (energy ray) curing type (see Patent Document 4), and the like are known. These are all used for the production of synthetic artificial leather.

  However, the environment-friendly urethane resins described above have the following problems. For the water-based type, a process of evaporating and removing water contained in the coating liquid is essential for forming a film. The hot melt type and TPU type must be heated and melted at 100 to 150 ° C. and 200 to 250 ° C., respectively. For this reason, there also exists the subject that the restriction | limiting about what is called usable time which can be used as a coating liquid is received. In addition, since the UV curable type can be handled as a coating solution at room temperature, there is no such problem as described above, but when the UV transmission to the coating film is insufficient, uneven curing occurs, especially in the thick film. There exists a subject that it is difficult to produce this in a favorable state. Further, in the case of the NCO group block type, there is a problem that the dissociated blocking agent is released because the coating agent is formed by dissociating the blocking agent during curing.

JP 2002-086662 A JP 2003-049147 A JP 2006-070058 A JP 2010-189797 A

  Accordingly, an object of the present invention is to provide a urethane prepolymer composition that solves the above-mentioned problems of the prior art. More specifically, it is a urethane prepolymer of a type that does not cause problems in the ultraviolet curing type or NCO group block type, and is used by increasing the molecular weight by reacting the active hydrogen in the component with a crosslinking agent, , Organic solvent and water, no solvent, liquid from 30 ° C, can be handled at temperatures from 30 ° C to 80 ° C, has few restrictions on pot life, and volatile organic substances into the atmosphere It is to provide an environment-friendly urethane prepolymer composition in which almost no release occurs. Another object of the present invention is to form a skin layer or an adhesive layer with a two-component coating agent comprising a urethane prepolymer composition having the above characteristics and a polyisocyanate crosslinking agent, and the coating agent. To provide synthetic artificial leather.

  The above object is achieved by the present invention described below. That is, the present invention is a urethane prepolymer composition that is used by increasing the molecular weight by reacting active hydrogen in its components with a crosslinking agent, and at least a hydroxyl group-terminated urethane prepolymer having a hydroxyl value of 10 to 100 mgKOH / g. 20 to 80% by mass, and further contains 20 to 80% by mass of an oligomer having a hydroxyl value of 20 to 400 mgKOH / g and having no urethane bond, which can be crosslinked with the above-mentioned crosslinking agent, as the polymer medium. A urethane prepolymer composition having a non-volatile content of 100% and being liquid at a temperature of at least 30 ° C.

  As a preferable form of the urethane prepolymer composition described above, the hydroxyl group-terminated urethane prepolymer is a reaction product of an oligomer, a glycol component and an isocyanate compound; at least the hydroxyl group-terminated urethane prepolymer per molecule. The oligomer having 2 or 3 functional groups and the urethane bond-free oligomer has at least one of 2 or 3 functional groups per molecule; the oligomer used as the polymer medium further includes a short chain Mixing glycol is mentioned.

  As another embodiment, the present invention comprises 90 to 150 equivalent% of a polyisocyanate crosslinking agent having an NCO content of 5 to 35 mass% with respect to the average hydroxyl value of the urethane prepolymer composition. A two-component coating agent is provided.

  As another embodiment, the present invention provides a synthetic artificial leather comprising a base material and a skin layer, and the skin layer is formed of the above-mentioned two-component coating agent.

  As another embodiment, the present invention comprises a base material, an adhesive layer, and a skin layer, and the adhesive layer and the skin layer are formed by the two-component coating agent described above. Provide fake leather. As a preferable form of the synthetic artificial leather described above, an aqueous surface treatment agent is further applied to the surface of the skin layer.

  Moreover, the two-component coating agent using the urethane prepolymer composition of the present invention together with a crosslinking agent is applied to the release paper, and after heat-curing, it is heat-pressed to the surface of the synthetic artificial leather intermediate product. Thus, it can be suitably used in a method for producing a synthetic artificial leather that forms a skin, or a method for producing a synthetic artificial leather in which a coating agent is heated and cured after direct application to form a skin layer. Further, the two-component coating agent using the urethane prepolymer composition of the present invention together with a crosslinking agent is applied to the release paper, and the surface of the skin layer formed after heat-curing (in contact with the release paper) Furthermore, the coating agent is applied as an adhesive layer to the surface opposite to the coated surface, and this is applied to a substrate such as a nonwoven fabric, a woven fabric, or a knitted fabric, and then heat-cured to produce a synthetic dummy. It is suitably used in a method for producing synthetic artificial leather for producing leather.

  According to the present invention, there is no solvent without using an organic solvent or water, and it is liquid at a temperature of at least 30 ° C. and can be handled at a temperature of 30 ° C. to 80 ° C. The resulting coating agent is excellent in workability and the coating film obtained is stable and of good quality. By using this coating agent, it is possible to provide environmentally friendly synthetic artificial leather products. A useful urethane prepolymer composition is provided. Since the urethane prepolymer composition of the present invention does not contain an organic solvent or water, for example, when used in the production of synthetic artificial leather, the solvent evaporation removal step can be omitted. When used for the formation of synthetic artificial leather skin layers and adhesive layers, environmentally friendly products are provided because volatile organic matter, which was a problem during production, is rarely released into the atmosphere. it can.

Next, the present invention will be described in more detail with reference to preferred embodiments.
The urethane prepolymer composition of the present invention is a urethane prepolymer composition used by increasing the molecular weight by reacting, for example, a crosslinking agent such as polyisocyanate with active hydrogen in the component, and has a hydroxyl value of 10 to 100 mgKOH / 20 to 80% by mass of a hydroxyl group-terminated urethane prepolymer of g, and further 20 to 80% by mass of an oligomer having a hydroxyl value of 20 to 400 mgKOH / g and having no urethane bond as the polymer medium. And is substantially 100% non-volatile and liquid at a temperature of at least 30 ° C. Here, “substantially non-volatile content of 100%” as used in the present invention means that the solvent used for the reaction and dilution used in the conventional polyurethane solution is not used, but the remaining volatile components such as unreacted monomers are used. It means that the remaining volatile components are 5% or less.

  As a result of intensive studies to solve the above-mentioned problems of the prior art, the inventors of the present invention consisted of an oligomer / urethane prepolymer having a specific hydroxyl value and a solid content of substantially 100% by mass. When the composition is made into a material of a two-component coating agent that increases the molecular weight by reacting active hydrogen in these components with a crosslinking agent such as a polyisocyanate crosslinking agent, the coating agent obtained is, for example, The present invention has been found to be extremely useful for forming an adhesive layer and a skin layer of synthetic artificial leather. That is, the composition is in a liquid state at a temperature of at least 30 ° C., and more specifically in a liquid state at a temperature of 30 ° C. to 80 ° C. Therefore, when the coating agent is used, the pot life is long. The coating can be performed in a good state, and the formed adhesive layer and skin layer are excellent in properties, and as a result, synthetic artificial leather excellent in various performances can be obtained.

Hereinafter, the background of achieving the present invention will be described.
In general, when a composition containing, for example, a polyisocyanate crosslinking agent is applied to a urethane prepolymer containing a hydroxyl group having a solid content of 100% (that is, no solvent), the viscosity of the composition can be applied. In order to reduce the viscosity, it is necessary to heat at a temperature of 80 ° C to 130 ° C. For this reason, this composition has the restriction that the pot life is short, and there is a problem that the workability is inferior and the properties of the formed coating film are inferior. On the other hand, in the case of a one-shot mixed composition comprising an oligomer, a monomer (short-chain glycol), and a polyisocyanate cross-linking agent, the viscosity is low and the above heating process can be simplified, but the obtained synthesis There is a problem that the performance of the artificial leather is not satisfactory.

  In general, in order to design a urethane prepolymer to be liquid at 30 ° C. with a solid content of 100%, an amorphous polyol or diisocyanate compound is used as a forming component at 30 ° C., and There is a limitation of shortening the molecular weight. However, according to the study by the present inventors, the prepolymer obtained in this way can be applied as it is, but in this case, due to the fluidity of the prepolymer derived from the low molecular weight. A part of the formed coating film (coating liquid) flows to create a ripple pattern, so-called “coating film flow phenomenon” occurs, and a uniform film cannot be formed. For this reason, what was obtained with the coating liquid using the said prepolymer cannot maintain the quality as synthetic artificial leather.

  On the other hand, when the molecular weight of the urethane prepolymer is increased, the above-described problem of the flow phenomenon of the coating film is improved. In this case, in order to lower the prepolymer to the coating viscosity, the temperature is higher than 80 ° C. High temperature heating is required, and the pot life is extremely shortened, making it difficult to perform good coating.

  Therefore, it prevents the flow phenomenon of the coating liquid derived from the low molecular weight of the prepolymer, and stabilizes the performance of the synthetic artificial leather obtained when used for forming the adhesive layer and skin layer of the synthetic artificial leather. In order to achieve this, it is desired that the urethane prepolymer has a composition capable of keeping the handling temperature low during coating while increasing the molecular weight of the urethane prepolymer to a stable region where the above-mentioned problems do not occur.

  As a result of intensive studies from the above viewpoint, the present inventors have used a hydroxyl group-terminated urethane prepolymer having a hydroxyl value of 10 to 100 mgKOH / g, and further, for example, a crosslinking agent such as polyisocyanate as a medium for the prepolymer. A urethane prepolymer composition is formed by using an oligomer having a hydroxyl value of 20 to 400 mgKOH / g and not having a urethane bond, and the composition is made to have a high molecular weight with a crosslinking agent such as a polyisocyanate crosslinking agent. The present inventors have found that these problems can be solved, and have reached the present invention.

  Furthermore, the present inventors have determined that the mass content ratio of the urethane prepolymer in the mixed composition of the urethane prepolymer and the oligomer serving as the medium depends on the composition of the urethane prepolymer and the type of oligomer used as the medium. It was found that it is necessary to contain the urethane prepolymer in a range of 20 to 80% by mass or more, although the amount is different. More preferably, it is 35% or more, and can be arbitrarily set within the above range. That is, when the content of the urethane prepolymer is less than 20%, the amount of the oligomer used as the prepolymer medium becomes too large to be sufficiently supplemented with the urethane prepolymer. When used for forming a layer or the like, the obtained synthetic artificial leather is inferior in wear resistance. On the other hand, if it exceeds 80%, when the polyisocyanate crosslinking agent is reacted to increase the molecular weight of the composition and used, the viscosity becomes high during the reaction and an internal gel is generated. Can not be. As will be described later, the urethane prepolymer composition of the present invention can be used by mixing a short-chain glycol with an oligomer in order to improve the strength and durability of the formed film. If the mixing ratio is too high, the cold stretch resistance of the synthetic artificial leather formed decreases, so this point must be taken care of when short-chain glycols are used in combination.

  That is, in the present invention, a urethane prepolymer, which is designed to be liquid at a temperature of 30 ° C., can be applied at 30 to 80 ° C., and has a mixing ratio in the above range and each component has a specific hydroxyl value. For example, when forming a skin layer or an adhesive layer of synthetic artificial leather using a composition, a method of reacting a cross-linking agent such as a polyisocyanate cross-linking agent with the active hydrogen of each of the oligomer and the urethane prepolymer. By increasing the molecular weight of the composition, it was possible to obtain an excellent synthetic artificial leather. Hereinafter, the details of the urethane prepolymer composition of the present invention and the synthetic artificial leather obtained by using the composition will be described.

[Urethane prepolymer composition]
The urethane prepolymer composition of the present invention contains a hydroxyl group-terminated urethane prepolymer having a hydroxyl value of 10 to 100 mgKOH / g, and an oligomer having a hydroxyl value of 20 to 400 mgKOH / g is used in combination as the polymer medium. Each is contained in a specific ratio. Furthermore, the composition is substantially 100% non-volatile and is liquid at a temperature of at least 30 ° C. Here, the urethane prepolymer composition of the present invention is characterized by being in a liquid state at a temperature of 30 ° C., but is not particularly defined by the viscosity at 30 ° C. Hereinafter, the material which comprises this composition is demonstrated. In addition, the urethane prepolymer composition of the present invention having the above configuration may be hereinafter referred to as the composition.

(Hydroxyl-terminated urethane prepolymer)
The hydroxyl group-terminated urethane prepolymer constituting the urethane prepolymer composition of the present invention has a hydroxyl value of 10 to 100 mgKOH / g, and more preferably 20 to 100 mgKOH / g. When the hydroxyl value exceeds 100 mgKOH / g, for example, when the composition is used for the skin layer of synthetic artificial leather, the above-described flow phenomenon of the coating film occurs, and a uniform film cannot be formed. The quality as synthetic artificial leather cannot be maintained. On the other hand, when the hydroxyl value is less than 10 mgKOH / g, when the polyisocyanate cross-linking agent is reacted to increase the molecular weight of the composition, the composition becomes highly viscous during the reaction and an internal gel is generated. It becomes impossible to provide high quality products.

  The hydroxyl-terminated urethane prepolymer constituting the present invention can be synthesized by reacting an oligomer such as a polyol with an isocyanate compound, and in particular, it is a reaction product of an oligomer, a glycol component and an isocyanate compound. preferable. A polyol etc. are mentioned as an oligomer used in this case. For example, as a more suitable material for forming a synthetic artificial leather skin layer or adhesive layer, the urethane prepolymer may be a copolymer formed with an oligomer polyol, a short-chain glycol, and an isocyanate compound. To do. By comprising in this way, the synthetic | combination artificial leather obtained will satisfy | fill the performance calculated | required on the market, such as abrasion resistance performance and cold stretch-proof performance, on a higher level.

<Polyol>
Examples of polyols that can be used in producing the hydroxyl group-terminated urethane prepolymer constituting the present invention include polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, butadiene polyols, polyacryl polyols, and fats and oils. Examples thereof include a modified polyol, a silicone-modified polyol, a polycaprolactone polyol, a polyvalerolactone polyol, and a mixture thereof. In the case of producing a urethane prepolymer by selecting a polyol from these, in order to give fluidity at 30 ° C. to the urethane prepolymer composition of the present invention obtained by mixing the prepolymer and an oligomer used as a medium ( In other words, in order to be liquid at a temperature of 30 ° C., a composition that forms a liquid when a polyol that forms a liquid at 30 ° C. is selected or when the produced urethane prepolymer is mixed with an oligomer as a medium. Is preferably selected. Further, as described above, when producing the hydroxyl group-terminated urethane prepolymer constituting the present invention, for example, a high molecular weight obtained by reacting a polyisocyanate crosslinking agent to increase the molecular weight of the composition. In order to improve the strength and durability of the molecular weight coating, it is also a preferred form to copolymerize the polyol and the short chain glycol as mentioned above. In addition, the detail of the short chain glycol which can be used for manufacture of the above-mentioned urethane prepolymer is mentioned later.

  Examples of the polycarbonate-based polyol that can be used in producing the hydroxyl group-terminated urethane prepolymer listed above include, for example, short chain glycols as described later, dialkyl carbonate, alkylene carbonate, and the like alone or a mixture thereof. And polyols obtained by condensation reaction. Also in these, as described above, in order to give fluidity to the urethane prepolymer composition at 30 ° C., a polycarbonate-based polyol that is liquid at 30 ° C. is selected, or the produced urethane prepolymer is used as an oligomer as a medium. It is preferable to select a liquid composition when mixed. More specific examples include copolycarbonate diol of 1,5 pentanediol / 1,6 hexanediol = 50/50 (molar ratio).

  Examples of the polyether-based polyol that can be used in producing the above-mentioned hydroxyl-terminated urethane prepolymer include polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, and the like. It is done. In addition to the above, low molecular weight polyols and glycols and ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran (hereinafter abbreviated as THF) and the like can be obtained by addition polymerization of these alone or a mixture thereof by a known method. And a copolymer. Also in these, as described above, in order to give fluidity to the urethane prepolymer composition at 30 ° C., a polyether polyol that forms a liquid at 30 ° C. is selected, or the produced urethane prepolymer is an oligomer as a medium. It is preferable to select a composition that forms a liquid state when mixed with. More specifically, for example, poly-THF, THF-neopentyl glycol copolymer polyol and the like can be mentioned.

  Examples of the polyester-based polyol that can be used in producing the hydroxyl group-terminated urethane prepolymer listed above include, in addition to the condensates of short-chain glycols and dibasic acids described below, polyols and glycols as initiators. And lactone-based polyols such as polylactone diol, polycaprolactone diol, and polymethylvalerolactone diol obtained by ring-opening polymerization of lactone. Examples of the dibasic acid include succinic acid, glutaric acid, adipic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, tartaric acid, oxalic acid, malonic acid, pimelic acid, and suberin. Acid, glutaconic acid, azelaic acid, 1,4-cyclohexyldicarboxylic acid, α-hydromuconic acid, β-hydromuconic acid, α-butyl-α-ethylglutaric acid, α, β-diethylsuccinic acid, etc. Or two or more types. Also in these, as described above, in order to give fluidity to the urethane prepolymer composition at 30 ° C., a polyol that forms a liquid at 30 ° C. is selected, or the produced urethane prepolymer is mixed with an oligomer as a medium. In this case, it is preferable to select a liquid composition.

<Short chain glycol>
As described above, when producing the hydroxyl-terminated urethane prepolymer constituting the present invention, in order to improve the strength and durability of the film formed by increasing the molecular weight of the composition of the present invention, together with the above-mentioned polyols Short chain glycols can be copolymerized. Examples of the short-chain glycol that can be used in this case include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8- Examples include aliphatic glycols such as octanediol, 1,9-nonanediol, and neopentyl glycol, alicyclic glycols such as bishydroxymethylcyclohexane and cyclohexane-1,4diol, and aromatic glycols such as xylylene glycol.

<Isocyanate compound>
The hydroxyl group-terminated urethane prepolymer constituting the present invention can be synthesized by reacting an isocyanate compound with the polyol as described above. As an isocyanate compound which can be used when manufacturing a hydroxyl-terminated urethane prepolymer, the following are mentioned, for example. 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate, naphthalene diisocyanate, diphenyl ether diisocyanate, diphenyl sulfone diisocyanate , And the like, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine methyl ester diisocyanate, methylene diisocyanate, isopropylene diisocyanate, lysine diisocyanate, 1,5-octylene diisocyanate, Aliphatic, such as dimer acid diisocyanate, and isophorone diisocyanate , Cyclohexane diisocyanate, 4,4′-methylenedicyclohexyl diisocyanate, hydrogenated tolylene diisocyanate, isopropylidene dicyclohexyl-4,4′-diisocyanate, and the like.

  Among the isocyanate compounds listed above, in order to give the synthesized urethane prepolymer a liquid region at 30 ° C., in particular, 1,6-hexane diisocyanate, isophorone diisocyanate, 4,4′- Methylene dicyclohexyl diisocyanate, 2,4-tolylene diisocyanate / 2,6 tolylene diisocyanate = 80/20 (hereinafter referred to as TDI (−80)) and the like are preferable.

<Method for synthesizing hydroxyl-terminated urethane prepolymer>
In the synthesis of the hydroxyl group-terminated urethane prepolymer constituting the present invention, a conventionally known method can be used, and is not particularly limited. However, in order to promote the reaction, a conventionally known amine system used for urethane synthesis reaction is used. These organic metal catalysts can be used alone or in combination of two or more.

(Oligomer used as a medium)
The urethane prepolymer composition of the present invention uses a hydroxyl group-terminated urethane prepolymer having a hydroxyl value of 10 to 100 mgKOH / g constructed as described above, and further has a hydroxyl value of 20 to 400 mgKOH / g as a prepolymer medium. It is characterized in that it is composed of an oligomer having no urethane bond and is substantially liquid with a non-volatile content of 100% at a temperature of at least 30 ° C. In addition, in the above, the hydroxyl value in the case where a plurality of oligomers are mixed and used is represented by the average value of the mixture.

  Hereinafter, the oligomer used as the medium of the urethane prepolymer will be described. The hydroxyl value of the oligomer used as a medium in the present invention is required to be 20 to 400 mgKOH / g. That is, when the hydroxyl value of the oligomer used in combination as a medium exceeds 400 mgKOH / g, for example, when a film such as a skin layer of synthetic leather is formed, a urethane prepolymer composition containing the oligomer is converted to a polyisocyanate. When the polymer is cured with a cross-linking agent such as a cross-linking agent, the resulting film becomes hard. On the other hand, when the hydroxyl value is less than 20 mgKOH / g, the melt viscosity is high, and when mixed with a hydroxyl group-terminated urethane prepolymer, it does not become liquid at 30 ° C.

  A polyol is suitable as an oligomer used as a prepolymer medium constituting the urethane prepolymer composition of the present invention. Moreover, in order to improve the strength and durability of a film formed by increasing the molecular weight of the composition of the present invention, in the present invention, a short-chain glycol as described later can be mixed with an oligomer used as a medium.

  Suitable polyols for use as the medium basically include those similar to those used for the synthesis of the hydroxyl-terminated urethane prepolymer described above. Usable polyols include, for example, polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, butadiene polyols, polyacryl polyols, oil-modified polyols, silicone-modified polyols, polycaprolactone polyols, and polyvalerolactone polyols. Or a mixture thereof. In particular, in order to give fluidity at 30 ° C. to the urethane prepolymer composition of the present invention that is configured in a mixed state with the hydroxyl group-terminated urethane prepolymer described above, is a polyol that is liquid at 30 ° C. selected? It is preferable to select a composition that forms a liquid state when mixed with the urethane prepolymer synthesized as described above.

  Specific examples of the polycarbonate-based polyol and the polyether-based polyol described above are the same as those used for the synthesis of the hydroxyl group-terminated urethane prepolymer described above, and thus the description thereof is omitted.

  In addition, as described above, the oligomer used as a medium constituting the urethane prepolymer composition of the present invention includes a short-chain glycol for improving the strength and durability of the film formed by increasing the molecular weight of the composition. Can be mixed. As for the amount used, it is preferable to mix the short-chain glycol in the range of about 0.5 to 50 parts by mass, more preferably 1 to 25 parts by mass with respect to 100 parts by mass of the oligomer used as the medium. That is, if the mixing ratio of the short-chain glycol is too high, for example, when it is used for forming a skin layer of synthetic artificial leather, the cold stretch resistance is undesirably lowered. Examples of the short-chain glycols to be mixed at this time include the same short-chain glycols used for the synthesis of the hydroxyl-terminated urethane prepolymer. For example, ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4 Fats such as butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, etc. Aromatic glycols such as aliphatic glycols, bishydroxymethylcyclohexane and cyclohexane-1,4diol, and xylylene glycols.

(Composition of hydroxyl-terminated urethane prepolymer and oligomer used as medium)
The urethane prepolymer composition of the present invention contains 20 to 80% by mass of the hydroxyl group-terminated urethane prepolymer described above and 20 to 80% by mass of an oligomer used as a medium. More preferably, although it depends on the composition of the urethane prepolymer and the type of oligomer used as the medium, it is more preferable that the mass content ratio of the urethane prepolymer in the composition is 35% by mass or more.

(Other additives)
In addition to the components described above, the urethane prepolymer composition of the present invention, if necessary, depending on the purpose of use, for example, an ultraviolet absorber, an antioxidant, a colorant, a flame retardant, an inorganic filler such as silica, alumina, Organic fillers such as urethane beads and acrylic beads can be contained.

[Two-component coating agent]
The urethane prepolymer composition of the present invention described above is used when forming a film by reacting active hydrogen in the component with a crosslinking agent to increase the molecular weight. The urethane prepolymer composition of the present invention has a high molecular weight when used as a skin agent for forming a skin layer on the surface of a substrate or as an adhesive for bonding a separately formed skin layer to a substrate. Examples of the crosslinking agent used for the crosslinking reaction include a polyisocyanate (including a blocking agent) crosslinking agent, a melamine crosslinking agent, an epoxy crosslinking agent, and a carbodiimide crosslinking agent. In particular, the crosslinking method of the coating film comprising the urethane prepolymer composition of the present invention is preferably a crosslinking method using a polyisocyanate crosslinking agent utilizing reactivity with hydroxyl groups or urethane groups in the components. Furthermore, considering the suppression of the release of volatile organic substances into the atmosphere, the polyisocyanate cross-linking agent is preferably a non-blocking agent and used in a two-pack type.

  The urethane prepolymer composition of the present invention becomes an environment-friendly and excellent two-component coating agent by mixing with a polyisocyanate crosslinking agent. The polyisocyanate crosslinking agent for constituting the two-component coating agent preferably has an NCO content of 5 to 35% by mass. The two-component coating agent of the present invention contains a polyisocyanate crosslinking agent having an NCO content of 5 to 35% by mass with respect to the average hydroxyl value of the urethane prepolymer composition of the present invention at 90 to 150 equivalent%. It is characterized by.

  The polyisocyanate crosslinking agent used above is not particularly limited as long as it is within the scope of the present invention, and those that have been widely used in the past can be used. Specifically, HDI (hexamethylene diisocyanate), TDI (tolylene diisocyanate), MDI (diphenylmethane diisocyanate) and other bullet types, isocyanurate types, adduct types, modified liquid types, etc., alone or in combination Can be used in combination. The NCO content of the polyisocyanate crosslinking agent is preferably 5 to 35% by mass. The amount of the polyisocyanate crosslinking agent used is preferably in the range of 90% to 150%, particularly preferably 98% to 110% of the reaction equivalent with respect to the average hydroxyl value of the urethane prepolymer composition. Examples of commercially available products include lupranate MP-102 [NCO content 22.8%], lupranate MI [NCO content 33.3%], lupranate MM103 [NCO content 29.5%] (above, All are manufactured by BASF), Duranate 24A-100 [NCO content 23.5%], Duranate TLA-100 [NCO content 21.1%] (all are manufactured by Asahi Kasei Chemicals Corporation), and the like. It is done.

[Synthetic leather]
The above-described two-component coating agent comprising the urethane prepolymer composition of the present invention and a polyisocyanate crosslinking agent can be suitably used particularly when producing synthetic artificial leather. Specifically, in a synthetic artificial leather composed of a base material and an outer skin layer, or in a synthetic artificial leather composed of a base material, an adhesive layer and an outer skin layer, the outer skin layer, or the outer skin layer and the adhesive layer By forming using the two-component coating agent of the present invention, it becomes an excellent synthetic artificial leather of the present invention which is an environment-friendly product. The two-component coating agent of the present invention contains a urethane prepolymer composition having a specific mixing ratio that is liquid at a temperature of 30 ° C. and can be applied at 30 to 80 ° C. When the agent layer is formed of the composition, the pot life is long, and the composition can be applied to a substrate or the like in a good state. Further, the urethane prepolymer constituting the composition coated on a substrate or the like, and the active hydrogen possessed by the oligomer of the medium, respectively, and the polysiloxane constituting the two-component coating agent of the present invention. By making the composition have a high molecular weight by a method of reacting with an isocyanate crosslinking agent, an excellent synthetic artificial leather having no problem of “coating flow phenomenon” can be obtained. Since the two-component coating agent of the present invention does not contain an organic solvent or water, when a synthetic artificial leather is produced as described above, almost no volatile organic matter is released into the atmosphere. , Environmentally friendly products can be provided.

  The two-component coating agent of the present invention used when forming a skin layer, an adhesive layer or the like of the synthetic artificial leather of the present invention contains the urethane prepolymer composition of the present invention described above. . For this reason, the content ratio of the hydroxyl group-terminated urethane prepolymer in the two-component coating agent and the oligomer having no urethane bond as the polymer medium is the mass content ratio of the urethane prepolymer in the composition, It is 20 mass%-80 mass%. When the composition of the present invention is used as a material for forming synthetic artificial leather, a more preferable mass content ratio of the urethane prepolymer is 35% by mass or more. If the mass content ratio of the urethane prepolymer is less than 20% by mass, it is difficult to sufficiently supplement the amount of the oligomer having no urethane bond with the urethane prepolymer, and the resulting synthetic artificial leather has wear resistance. It becomes inferior. On the other hand, when it exceeds 80% by mass, when the polyisocyanate cross-linking agent is reacted to increase the molecular weight of the composition, the viscosity becomes high during the reaction and an internal gelled product is generated. There is a negative effect that the service cannot be provided.

  However, the other components can be arbitrarily set as long as the above range is satisfied. In addition, when the urethane prepolymer composition of the present invention is used as a material for forming the synthetic artificial leather of the present invention, a short-chain glycol can be mixed with an oligomer to be contained as a prepolymer medium. If the mixing ratio of the short-chain glycol in the inside becomes too high, the cold stretch resistance of the resulting synthetic artificial leather tends to decrease. For this reason, when mixing short chain glycol with the oligomer used as a prepolymer medium, it is preferable to make the quantity into the range of about 0.5-50 mass parts with respect to 100 mass parts of oligomers.

  The hydroxyl value of the hydroxyl-terminated urethane prepolymer constituting the present invention is 10 to 100 mgKOH / g, but when used as a synthetic artificial leather forming material, it is particularly preferably 20 to 100 mgKOH / g. When the hydroxyl value exceeds 100 mgKOH / g, a flow phenomenon of the coating film occurs, a uniform film cannot be formed, and the quality as a synthetic artificial leather cannot be maintained. On the other hand, when the hydroxyl value is less than 10 mgKOH / g, the viscosity becomes high during the reaction with the cross-linking agent, and an internal gel is generated, making it difficult to provide high-quality synthetic artificial leather.

  Moreover, the synthetic artificial leather obtained by the two-component coating agent containing this by making the hydroxyl-terminated urethane prepolymer constituting the present invention a copolymer of a polyol and a short-chain glycol, It satisfies the performance required in the market, such as wear resistance and cold stretch resistance, at a high level.

  As described above, the hydroxyl value of the oligomer, which is a prepolymer medium, constituting the urethane prepolymer composition of the present invention is 20 mgKOH / g or more and 400 mgKOH / g or less. When a two-component coating agent containing an oligomer having a hydroxyl value exceeding 400 mgKOH / g is used as a material for forming a synthetic artificial leather skin layer, the urethane prepolymer composition is increased in molecular weight by a polyisocyanate crosslinking agent. The film obtained by (curing) becomes hard. Therefore, when a skin layer is formed using such a composition, the surface of the synthetic artificial leather obtained becomes hard, and when used for forming an adhesive layer, adhesion may be insufficient.

As a specific method for producing a synthetic artificial leather using the two-component coating agent of the present invention, for example, there are methods as shown below. By these methods, synthesis with high performance and flexibility is possible. You can get fake leather.
(1) After applying the two-component coating agent of the present invention to a release paper and heat-curing (for example, 150 ° C./2 to 7 minutes) to form a skin layer, the obtained skin layer is A method for producing synthetic artificial leather, in which a skin is formed by thermocompression bonding to a polyurethane leather surface produced by a wet method or a dry method.
(2) After directly applying the two-component coating agent of the present invention to the above-described polyurethane leather surface, the coated surface is cured by heating (for example, 150 ° C./2 to 7 minutes) to form a skin layer. , A method for producing synthetic artificial leather having a skin surface.
(3) The two-component coating agent of the present invention is applied to a release paper and cured by heating (for example, 150 ° C./2 to 7 minutes) to form a skin layer, and then the surface of the skin layer (The surface opposite to the surface in contact with the release paper) is coated with the two-component coating agent of the present invention to form an adhesive layer, which is suitable for bonding the adhesive layer to a base fabric. Pre-curing (for example, conditions of 120 ° C./1-5 minutes). Then, the pre-cured adhesive layer is bonded to the base fabric, and then completely cured (for example, 150 ° C./2 to 7 minutes), and then peeled off from the release paper to obtain a synthetic artificial leather .

  The synthetic artificial leather of the present invention that can be produced as described above can be further coated with an aqueous surface treatment agent on the surface of the skin layer. By performing the surface treatment with the surface treatment agent, it becomes possible to obtain a more excellent synthetic artificial leather.

  The synthetic artificial leather of the present invention obtained by a simple method as described above has a strong skin layer, excellent adhesion and texture, and selection of an oligomer used as a medium constituting the urethane prepolymer composition of the present invention. In addition, hydrolysis, light resistance, heat resistance, oleic acid resistance, cold resistance, and solvent resistance can be applied to the skin layer and adhesive layer by combining polyols, short-chain glycols, and isocyanate compounds used in the synthesis of urethane prepolymers. And is suitable for manufacturing all synthetic artificial leather products such as shoes, bags, clothing, furniture, and vehicle seats.

  Hereinafter, the present invention will be described more specifically with reference to examples, comparative examples, and application examples using the same, but the present invention is not limited thereto. In the following text, “parts” and “%” are based on mass.

[Examples and Comparative Examples]
Example 1
100 parts of a copolycarbonate diol (liquid at 20 ° C.) of 1,5 pentanediol / 1,6 hexanediol = 50/50 (molar ratio) having a hydroxyl value of 56.1 mgKOH / g, and 6.2 parts of ethylene glycol In addition, 16.8 parts of HDI was added and reacted at 70 ° C. for 1 hour. Thereafter, 300 ppm of DBU-octylate was added as a catalyst and reacted for another 3 hours to obtain a urethane prepolymer having a solid content of 100% and a hydroxyl value of 45.6 mgKOH / g at 20 ° C.

  In addition to the urethane prepolymer obtained above, 74.4 parts of poly-THF (liquid at 20 ° C.) having a hydroxyl value of 172.6 mgKOH / g and 1,5 having a hydroxyl value of 56.1 mgKOH / g 73.6 parts of a copolycarbonate diol (liquid at 20 ° C.) of pentanediol / 1,6 hexanediol = 50/50 (molar ratio) was added. As a result, the urethane prepolymer composition of this example having a urethane prepolymer content of 45%, an average hydroxyl value of 83.3 mgKOH / g, and liquid at 30 ° C. was obtained.

(Example 2)
100 parts of a copolycarbonate diol (liquid at 20 ° C.) of 1,5 pentanediol / 1,6 hexanediol = 50/50 (molar ratio) having a hydroxyl value of 56.1 mgKOH / g and 3.1 parts of ethylene glycol In addition, 12.6 parts of HDI was added and reacted at 70 ° C. for 1 hour. Then, 250 ppm of zinc 2-ethylhexylate was added as a catalyst and reacted for another 3.5 hours to obtain a urethane prepolymer liquid at 20 ° C. having a solid content of 100% and a hydroxyl value of 24.2 mgKOH / g. It was.

  In addition to the urethane prepolymer obtained above, 93 parts of poly-THF (liquid at 20 ° C.) having a hydroxyl value of 172.6 mgKOH / g and 1,5-pentanediol having a hydroxyl value of 56.1 mgKOH / g 117 parts of a copolycarbonate diol (liquid at 20 ° C.) of 1,6 hexanediol = 50/50 (molar ratio) was added. This obtained the urethane prepolymer composition of the present Example which is liquid at 30 ° C., having a urethane prepolymer content of 36% in the composition and an average hydroxyl value of 78.0 mgKOH / g.

(Example 3)
85 parts of a copolycarbonate diol (liquid at 20 ° C.) of 1,5 pentanediol / 1,6 hexanediol = 50/50 (molar ratio) having a hydroxyl value of 224.4 mgKOH / g and a hydroxyl value of 140.3 mgKOH / G of 1,5 pentanediol / 1,6 hexanediol = 50/50 (molar ratio) of copolycarbonate diol (liquid at 20 ° C.) 15 parts, ethylene glycol 16.6 parts, TDI (− 80) was added and reacted at 100 ° C. for 1 hour. Thereafter, 300 ppm of DBU-octylate was added as a catalyst, and the mixture was further reacted for 3 hours to obtain a urethane prepolymer having a solid content of 100% and a hydroxyl value of 92.0 mgKOH / g at 20 ° C.

  To the urethane prepolymer obtained above, 110.7 parts of poly-THF (liquid at 20 ° C.) having a hydroxyl value of 172.6 mgKOH / g and a hydroxyl value of 224.4 mgKOH / g, 1,5 158.2 parts of a copolycarbonate diol (liquid at 20 ° C.) of pentanediol / 1,6 hexanediol = 50/50 (molar ratio) was added. As a result, a urethane prepolymer composition of this example having a liquid content at 30 ° C. having a urethane prepolymer content of 38% and an average hydroxyl value of 161.1 mgKOH / g was obtained.

Example 4
100 parts of a THF-neopentyl glycol copolymer polyol (liquid at 20 ° C.) having a hydroxyl value of 62.3 mgKOH / g, 15.0 parts of 1,4 butanediol, and 29.0 parts of TDI (−80) And reacted at 100 ° C. for 1 hour. Thereafter, 150 ppm of dibutyltin dilaurate was added as a catalyst, and the mixture was further reacted for 2.5 hours to obtain a urethane prepolymer having a solid content of 100% and a hydroxyl value of 43.3 mgKOH / g at 20 ° C.

  To the urethane prepolymer part obtained above, 100 parts of THF-ethylene glycol copolymer polyol (liquid at 20 ° C.) having a hydroxyl value of 62.3 mgKOH / g was further added. This obtained the urethane prepolymer composition of the present Example which is liquid at 30 ° C. with a content of urethane prepolymer in the composition of 59% and an average hydroxyl value of 51.1 mgKOH / g.

(Example 5)
100 parts of a THF-neopentyl glycol copolymer polyol (liquid at 20 ° C.) having a hydroxyl value of 62.3 mgKOH / g, 10.0 parts of 1,4-butanediol, and 24 of TDI (−80) .2 parts were added and reacted at 100 ° C. for 1 hour. Thereafter, 250 ppm of DBU-oleate was added as a catalyst, and further reacted for 3.5 hours to obtain a urethane prepolymer having a solid content of 100% and a hydroxyl value of 23.4 mgKOH / g at 20 ° C. It was.

  To the urethane prepolymer obtained above, 500 parts of THF-ethylene glycol copolymer polyol (liquid at 20 ° C.) having a hydroxyl value of 62.3 mgKOH / g was further added. As a result, a urethane prepolymer composition of this example having a content of urethane prepolymer in the composition of 21% and an average hydroxyl value of 54.1 mgKOH / g and being liquid at 30 ° C. was obtained.

(Comparative Example 1)
80 parts of 1,5-pentanediol / 1,6 hexanediol = 50/50 (molar ratio) copolycarbonate diol (liquid at 20 ° C.) having a hydroxyl value of 56.1 mgKOH / g and a hydroxyl value of 62.3 mgKOH / G of THF-neopentylglycol copolymer polyol (liquid at 20 ° C.) 20 parts, 1.5 parts of 1,4 butanediol, 24.2 parts of TDI (−80) are added, and 100 ° C. For 1 hour. Then, 150 ppm of dioctyltin diacetate was added and reacted for another 3 hours to obtain a urethane prepolymer of Comparative Example which was liquid at 30 ° C. and had a solid content of 100% and a hydroxyl value of 26.3 mgKOH / g.

(Comparative Example 2)
100 parts of THF-neopentyl glycol copolymer polyol (liquid at 20 ° C.) having a hydroxyl value of 62.3 mgKOH / g, 10.0 parts of 1,3 butanediol, and 4,4′-methylenedicyclohexyl diisocyanate 29.1 parts were added and reacted at 110 ° C. for 2 hours. Thereafter, 150 ppm of dibutyltin dilaurate was added as a catalyst, and the mixture was further reacted for 2 hours to obtain a urethane prepolymer having a solid content of 100% and a hydroxyl value of 44.9 mgKOH / g at 20 ° C.

  To the urethane prepolymer obtained above, 300 parts of polyethylene glycol (liquid at 20 ° C.) having a hydroxyl value of 561.0 mgKOH / g was further added. This obtained the urethane prepolymer composition of the comparative example whose average hydroxyl value is 397.5 mgKOH / g and whose content rate of the urethane prepolymer in a composition is 32%, and is liquid at 30 degreeC.

(Comparative Example 3)
100 parts of a 1,5 pentanediol / 1,6 hexanediol = 50/50 (molar ratio) copolycarbonate diol (liquid at 20 ° C.) having a hydroxyl value of 224.4 mgKOH / g, and 1,6 hexanediol 47.2 parts of HDI was added to 47.2 parts and reacted at 70 ° C. for 4 hours to obtain a urethane prepolymer liquid at 20 ° C. having a solid content of 100% and a hydroxyl value of 104.9 mgKOH / g. It was.

  In addition to the urethane prepolymer obtained above, 74.4 parts of poly-THF (liquid at 20 ° C.) having a hydroxyl value of 172.6 mgKOH / g and 1,5 having a hydroxyl value of 56.1 mgKOH / g 73.6 parts of a copolycarbonate diol (liquid at 20 ° C.) of pentanediol / 1,6 hexanediol = 50/50 (molar ratio) was added. This obtained the urethane prepolymer composition of the comparative example whose average hydroxyl value is 70.3 mgKOH / g, the content rate of the urethane prepolymer in a composition is 59%, and is a liquid at 30 degreeC.

(Comparative Example 4)
12.2 parts of TDI (T-80) was added to 100 parts of polypropylene glycol having a hydroxyl value of 56.1 mgKOH / g and 1.9 parts of ethylene glycol, and reacted at 100 ° C. for 1 hour. Thereafter, 120 ppm of dioctyltin diacetate was added and reacted for another 3 hours to obtain a urethane prepolymer of a comparative example having a solid content of 100% and a hydroxyl value of 9.9 mgKOH / g and a high viscosity at 100 ° C. The prepolymer produced a gel at 30 ° C.

(Comparative Example 5)
100 parts of 1,5-pentanediol / 1,6 hexanediol = 50/50 (molar ratio) copolycarbonate diol (liquid at 20 ° C.) having a hydroxyl value of 56.1 mgKOH / g, and ethylene glycol 6.2 16.8 parts of HDI was added to the part and reacted at 70 ° C. for 1 hour. Thereafter, 250 ppm of DBU-octylate was added as a catalyst, and the mixture was further reacted for 3 hours to obtain a urethane prepolymer having a solid content of 100% and a hydroxyl value of 45.6 mgKOH / g at 20 ° C.

  The urethane prepolymer obtained above further comprises 223.7 parts of poly-THF (liquid at 20 ° C.) having a hydroxyl value of 172.6 mgKOH / g and 1,5 having a hydroxyl value of 56.1 mgKOH / g. 422.1 parts of a copolycarbonate diol (liquid at 20 ° C.) of pentanediol / 1,6 hexanediol = 50/50 (molar ratio) was added. This obtained the urethane prepolymer composition of the comparative example which contains 16% of urethane prepolymers whose average hydroxyl value is 83.3 mgKOH / g. The ethylene glycol content at this time was 2.3%.

(Comparative Example 6)
By further adding 11.7 parts of ethylene glycol to 100 parts of the urethane prepolymer composition of Comparative Example 5, the content was adjusted to the same ethylene glycol content as that of the urethane prepolymer composition of Example 1, and the average A comparative urethane prepolymer composition having a hydroxyl value of 114.1 mgKOH / g was obtained.

(Characteristics of each example)
The properties of the urethane prepolymer compositions of Examples and Comparative Examples obtained as described above are summarized in Table 1 and Table 2, respectively. Specifically, the appearance of each urethane prepolymer composition at a temperature of 30 ° C., the viscosity at each liquid temperature shown in Table 1, coating suitability, the average hydroxyl value of the urethane prepolymer, the urethane prepolymer in the composition The contents and the hydroxyl values of the oligomers mixed with the urethane prepolymer constituting each composition are collectively shown.

[Application example]
Using the urethane prepolymer compositions of the above-described Examples and Comparative Examples, synthetic artificial leather was prepared by any of the following methods and evaluated by the methods described below.
(1) First, a composition to be evaluated is applied to a release paper, and then heat-cured to form a film (skin layer). Then, the obtained film is heated and pressure-bonded to the surface of a polyurethane leather base material to form a skin, and a skin layer is formed to produce a synthetic artificial leather.
(2) A method in which a synthetic artificial leather is produced by directly applying a composition to be evaluated to a substrate and then heating and curing to produce a skin layer.
(3) First, a composition to be evaluated is applied to a release paper, and then heat-cured to form a film (skin layer). Thereafter, the composition to be evaluated is further applied to the surface of the formed skin layer (the surface opposite to the surface in contact with the release paper) to form a semi-cured adhesive layer. Finally, a method of producing a synthetic artificial leather by bonding the formed adhesive layer surface to a base material such as a fabric and then heat-curing.

(Application 1)
While maintaining the urethane prepolymer composition of Example 3 at 70 ° C., 100 parts of the composition was reacted with lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. 55.5 parts of the group equivalent of 105% and 2 parts of FTR-5570 black (manufactured by Dainichi Seika Kogyo Co., Ltd .: 100% solid content colorant) are mixed to produce composition-1 before curing. did. Next, the pre-curing composition-1 was applied to a release paper (trade name: DNTP-155T-FLAT, manufactured by Dai Nippon Printing Co., Ltd.) while heating the coater to 100 ° C. so as to have a thickness of 50 μm. Was applied in a sheet form. After the application, it was cured at 150 ° C. for 5 minutes to form a cured film on the release paper.

  Next, while maintaining the urethane prepolymer composition of Example 1 at 70 ° C., 100 parts of the composition was treated with Lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. 27.4 parts which will be 100% of the reactive group equivalent was mixed to prepare composition-2 before curing. And the said composition-2 before hardening was apply | coated to the sheet form, heating a coater to 100 degreeC on the cured film produced above so that thickness might be set to 50 micrometers. After the coating, a cured / semi-cured film laminate formed by two types of urethane prepolymer compositions was prepared by being semi-cured at 120 ° C./2 minutes. Next, the semi-cured film side of the laminate was superposed on a substrate (woven fabric). The total thickness (including the release paper) in a state of being superposed on the base material was 1,200 μm, and this was pressure-contacted with a laminating roll having a 500 μm gap heated to 120 ° C. Subsequently, it was cured at 150 ° C. for 5 minutes, and then peeled from the release paper to produce a synthetic leather (pseudo leather).

Furthermore, to the synthetic leather obtained above, an aqueous surface treating agent Rezaroid D-7602 (manufactured by Dainichi Seika Kogyo Co., Ltd.) is used under conditions of 7 to 10 g / m ² · Dry in 2 passes of 100 mesh gravure roll. Attached. Thereafter, by embossing at 200 ° C., a synthetic artificial leather (leather) having an embossed finish with clear irregularities was obtained.

(Application example 2)
While maintaining the urethane prepolymer composition of Example 4 at 60 ° C., 100 parts of the composition was composed of Duranate 24A-100 having a NCO content of 23.5% as a polyisocyanate crosslinking agent (manufactured by Asahi Kasei Chemicals Corporation). ), 16.9 parts in an amount of 98% of the reactive group equivalent, 25 ppm of dibutyltin dilaurate as a crosslinking reaction accelerator, FTR-5501 white (manufactured by Dainichi Seika Kogyo Co., Ltd .: 100% solid content colorant) ) 3 parts were mixed to prepare composition-3 before curing. Next, the pre-curing composition prepared above while heating the coater to 90 ° C. so as to have a thickness of 50 μm on a release paper (trade name: AR-99SG, manufactured by Asahi Roll Co., Ltd.) 3 was applied in sheet form. After coating, the film was cured at 150 ° C./7 minutes to form a cured film on the release paper.

  Next, while maintaining the urethane prepolymer composition obtained in Example 5 at 50 ° C., 100 parts of the composition was combined with Luplanate MI (manufactured by BASF) having a NCO content of 33.3% as a polyisocyanate crosslinking agent. Was mixed with 12.4 parts to be 102% of the reactive group equivalent to prepare composition-4 before curing. And the said composition-4 before hardening was apply | coated to the sheet form, heating a coater at 80 degreeC so that thickness might be set to 75 micrometers on the cured film produced above. After the application, a cured / semi-cured film laminate formed by two kinds of urethane prepolymer compositions was prepared by being semi-cured at 120 ° C./3 minutes. Next, the semi-cured film side of the laminate was superposed on a substrate (woven fabric). The total thickness (including the release paper) in a state of being superposed on the base material was 1,150 μm, and this was pressure-contacted with a laminate roll having a 500 μm gap heated to 100 ° C. Subsequently, it was cured under conditions of 150 ° C./7 minutes, and then peeled from the release paper to produce a synthetic leather (pseudo leather).

(Application 3)
While maintaining the urethane prepolymer composition of Example 3 at 70 ° C., 100 parts of the composition was reacted with lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. A pre-curing composition-5 was prepared by mixing 55.1 parts of the group equivalent of 105% and 2 parts of the same FTR-5570 black used in Application Example 1. Then, after applying the pre-curing composition-5 to a release paper (trade name: AR-99SG) in a sheet form while heating the coater to 100 ° C. so that the thickness becomes 75 μm, 150 ° C. / Curing was performed for 5 minutes to form a cured film on the release paper.

  Next, the cured film prepared above was pressure bonded by applying heat at 170 ° C. from the release paper side to the raw fabric formed by forming a wet polyurethane resin foam layer on the base material (woven fabric). . Then, it peeled from the release paper and manufactured the synthetic artificial leather.

(Application 4)
While maintaining the urethane prepolymer composition of Example 2 at 70 ° C., 100 parts of the composition was mixed with lupranate MM103 (manufactured by BASF) having a NCO content of 29.5% as a polyisocyanate crosslinking agent. 20.2 parts, which is 102% of the above, and 2 parts of FTR-5570 black were mixed to prepare composition-6 before curing.

  Next, on the raw material having a wet polyurethane resin foam layer formed on the base material (woven fabric), the pre-curing composition-6 obtained above was heated to 100 ° C. so that the thickness was 75 μm. However, the pre-curing composition-6 was applied in the form of a sheet. Then, it hardened | cured on 150 degreeC / 7 minutes conditions, and the cured film was formed.

Then, the same Latheroid D-7602 as used in Example 1 was added to the cured film obtained above in a condition of 7 to 10 g / m ² · Dry with 2 passes of 100 mesh gravure roll. Thereafter, by embossing at 170 ° C., a synthetic artificial leather having an embossed finish with clear irregularities was obtained.

(Application comparison example 1)
As shown in Table 2, the urethane prepolymer of Comparative Example 4 was in a high-viscosity state during synthesis, and a gelled product lump was generated, making it impossible to produce a mixed composition with an oligomer.

(Application comparison example 2)
While maintaining the urethane prepolymer composition of Comparative Example 1 at 120 ° C., 100 parts of the composition was composed of Duranate TLA-100 (produced by Asahi Kasei Chemicals Co., Ltd.) having an NCO content of 21.1% as a polyisocyanate crosslinking agent. ) Was mixed with 9.5 parts of 100% of the reactive group equivalent to produce a pre-curing composition. However, the pre-curing composition could not be applied because the viscosity increased significantly in 2 to 3 minutes after mixing.

(Application comparison example 3)
While maintaining the urethane prepolymer composition of Comparative Example 3 at 50 ° C., 100 parts of the composition was reacted with lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. 55.1 parts of the group equivalent of 105%, DBN-octylate 300 ppm as a crosslinking reaction accelerator, and 2 parts of FTR-5570 black were mixed to prepare composition-7 before curing. Then, the composition before curing-7 while heating the coater to 80 ° C. so that the thickness becomes 50 μm on a release paper (trade name: DNTP-155T-FLAT, manufactured by Dai Nippon Printing Co., Ltd.) Was applied in a sheet form and then cured under conditions of 150 ° C./5 minutes to form a cured film on the release paper. When the obtained cured film was visually observed, a flow phenomenon of the coating film occurred.

  Next, while maintaining the urethane prepolymer composition of Example 1 at 70 ° C., 100 parts of the composition was treated with Lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. 27.4 parts which will be 100% of the reactive group equivalent was mixed to prepare composition-8 before curing. And on the film in which the flow phenomenon of the coating film produced above was seen, the pre-curing composition-8 was applied in a sheet form while heating the coater to 100 ° C. so that the thickness became 50 μm. . Thereafter, a cured / semi-cured film laminate formed by two types of urethane prepolymer compositions of Comparative Example 3 and Example 1 was prepared by being semi-cured at 120 ° C./2 minutes. Next, the semi-cured film side of the laminate was superposed on a substrate (woven fabric). The total thickness (including the release paper) when the laminate was superposed on the substrate was 1,200 μm, but this was pressure-contacted with a laminate roll with a 500 μm gap heated to 120 ° C. It was. Subsequently, it was cured at 150 ° C. for 5 minutes, and then peeled from the release paper to produce a synthetic leather. However, when the skin of the obtained synthetic leather was visually observed, holes were generated everywhere due to the flow phenomenon of the coating film produced during the production of the cured film, and a uniform film was not formed.

(Application comparison example 4)
While maintaining the urethane prepolymer composition of Comparative Example 2 at 60 ° C., 100 parts of the composition was mixed with lupranate MI (manufactured by BASF) having a NCO content of 33.3% as a polyisocyanate crosslinking agent. Of 91.2% of the above, 25 ppm of dibutyltin dilaurate as a crosslinking reaction accelerator, and 3 parts of FTR-5501 white were mixed to prepare composition-9 before curing. Next, the pre-curing composition-9 was applied to a release paper (trade name: AR-99SG) in a sheet form while heating the coater to 90 ° C. so that the thickness was 50 μm. After application, the film was cured under conditions of 150 ° C./7 minutes to form a cured film.

  Next, while maintaining the urethane prepolymer composition of Example 1 at 70 ° C., 100 parts of the composition was treated with Lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. Then, 27.4 parts, which is 100% of the reactive group equivalent, were mixed to prepare composition-10 before curing. And after apply | coating the said composition 10 before hardening to a sheet form, heating a coater to 100 degreeC so that thickness may be set to 50 micrometers on the cured film produced above, in 120 degreeC / 2 minutes. A cured / semi-cured film laminate formed by the two types of urethane prepolymer compositions of Comparative Example 2 and Example 1 was prepared by semi-curing under the above conditions. Next, the semi-cured film side of the laminate was superposed on a substrate (woven fabric). The total thickness (including the release paper) in a state of being superposed on the base material was 1,200 μm, and this was pressure-contacted with a laminating roll having a 500 μm gap heated to 100 ° C. Subsequently, it was cured under conditions of 150 ° C./5 minutes, and then peeled from the release paper to produce a synthetic leather (pseudo leather). However, the obtained synthetic leather had a hard texture.

(Application Comparative Example 5)
While maintaining the urethane prepolymer composition of Comparative Example 5 at 60 ° C., 100 parts of the composition was reacted with lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. 29.6 parts, which is 102% of the group equivalent, and 2 parts of FTR-5570 black were mixed to prepare composition-11 before curing. Next, the pre-curing composition-11 prepared above was applied to a release paper (trade name: AR-99SG) in a sheet form while heating the coater to 90 ° C. so that the thickness was 50 μm. After application, the film was cured under conditions of 150 ° C./5 minutes to form a cured film.

  Next, while maintaining the urethane prepolymer composition of Example 1 at 70 ° C., 100 parts of the composition was treated with Lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. Then, 27.4 parts to be 100% of the reactive group equivalent were mixed to prepare composition-12 before curing. And after apply | coating the said composition 12 before hardening to a sheet form, heating a coater to 100 degreeC so that thickness may be set to 50 micrometers on the cured film produced above, in 120 degreeC / 2 minutes. A cured / semi-cured film laminate formed by two types of oligomer / urethane prepolymer was prepared. Next, the semi-cured film side of the laminate was superposed on a substrate (woven fabric). The total thickness of the superposed film (including the release paper) and the substrate was 1150 μm. The superposed product was pressed and adhered with a laminate roll heated to 120 ° C. and having a gap of 500 μm. Then, after making it harden | cure on 150 degreeC / 5 minutes conditions, it peeled from the release paper and obtained the synthetic leather. The obtained synthetic leather had low surface lubricity.

(Application Comparative Example 6)
While maintaining the urethane prepolymer composition of Comparative Example 6 at 60 ° C., 100 parts of the composition was reacted with lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. 38.2 parts, which is 102% of the base equivalent, and 2 parts of FTR-5570 black were mixed to prepare composition-13 before curing. And after apply | coating the said composition 13 before hardening to a release paper (brand name: AR-99SG) in a sheet form, heating a coater to 90 degreeC so that thickness may be set to 50 micrometers, 150 degreeC / Curing was performed for 5 minutes to form a cured film.

  Next, while maintaining the urethane prepolymer composition of Example 1 at 70 ° C., 100 parts of the composition was treated with Lupranate MP-102 (BASF) having an NCO content of 22.8% as a polyisocyanate crosslinking agent. Then, 27.4 parts, which is 100% of the reactive group equivalent, were mixed to prepare composition-14 before curing. And after apply | coating the said composition 14 before hardening to a sheet form, heating a coater to 100 degreeC on the cured film produced above so that thickness may be set to 50 micrometers, 120 degreeC / 2 minutes. A cured / semi-cured film laminate formed by two types of urethane prepolymer compositions of Comparative Example 6 and Example 1 was prepared by semi-curing under conditions. Next, the semi-cured film side of the laminate was superposed on a substrate (woven fabric). The total thickness (including the release paper) in a state of being superposed on the base material was 1,150 μm, and this was pressure-contacted with a laminating roll having a 500 μm gap heated to 120 ° C. Next, after curing at 150 ° C. for 5 minutes, it was peeled from the release paper to produce a synthetic leather.

[Reference example]
Conventionally used in the manufacture of synthetic artificial leather, using a solvent-type skin agent and a solvent-type adhesive consisting of a preparation of the following formulation, forming a skin layer and an adhesive layer under the conditions shown below, The synthetic artificial leather of Reference Example 1 was produced by bonding to the base material (woven fabric) shown in FIG.

(Reference Example 1)
The synthetic artificial leather of Reference Example 1 was produced by forming a coating film under the above conditions under the conditions described below for producing synthetic artificial leather, forming a skin layer and an adhesive layer, aging, and peeling from the release paper.
<Skin layer>
(Preparation)
・ Rezamin ME-8106 (manufactured by Dainichi Seika Kogyo Co., Ltd., 70% solvent) 100 parts DMF 33 parts (release paper) AR-99SG
(Coating amount) 250 μm / wet
(Drying conditions) 100 ° C./2 minutes → 120 ° C./3 minutes (film thickness) about 50 μm

<Adhesive layer>
(Preparation)
・ Rezamin UD-750SA (manufactured by Dainichi Seika Kogyo Co., Ltd., 25% solvent-containing product) 100 parts ・ Rezamin UD-crosslinking agent (manufactured by Dainichi Seika Kogyo Co., Ltd., 25% solvent-containing product) 15 parts Rezamin UD-102 accelerator (manufactured by Dainichi Seika Kogyo Co., Ltd., 98% solvent) 10 parts / DMF 20 parts / MEK 20 parts (coating amount) 100 μm / wet
(Preliminary drying conditions) 80 ° C./2 minutes (film thickness) about 50 μm
(Lamination with base material) Laminate roll on fabric, pressure bonding (aging) at 40 ° C./0 μm, 50 ° C. × 48 hours

(Reference Example 2)
Synthetic artificial leather preparation conditions The following conditions are applied to a wet polyurethane resin surface that has been prepared under the following conditions using a solvent-type skin agent that has been used in the manufacture of synthetic artificial leather, and is prepared with the following formulation: The film for the skin layer formed on the release paper was pressure bonded by applying heat at 170 ° C. from the release paper side, and then peeled from the release paper to produce the synthetic artificial leather of Reference Example 2. .

<Surface of wet polyurethane resin>
(Preparation)
・ Rezamin CU-9443 (manufactured by Dainichi Seika Kogyo Co., Ltd., containing 70% solvent) 100 parts ・ 140 parts of DMF ・ Rezamin CUT-102 (manufactured by Dainichi Seika Kogyo Co., Ltd.) 3 parts ・ Seika Seven BS -780 (S) Black (manufactured by Dainichi Seika Kogyo Co., Ltd.) 5 parts (base material) woven fabric (coating amount) 1,000 μm / wet
(Coagulation) DMF 5% aq / 25 ° C / 10 minutes (Dry) 120 ° C / 5 minutes

<Skin layer>
(Preparation)
・ Rezamin ME-8106 (manufactured by Dainichi Seika Kogyo Co., Ltd., 70% solvent) 100 parts DMF 33 parts (release paper) AR-99SG
(Coating amount) 350 μm / wet
(Drying conditions) 100 ° C./2 minutes → 120 ° C./3 minutes (film thickness) about 75 μm

  The environmentally friendly synthetic artificial leather of application examples, comparative application examples, and reference examples obtained using solventless raw materials as described above has cold stretch resistance, abrasion resistance, and flexibility according to the methods and criteria described below. The evaluation results obtained are shown in Table 3.

[Evaluation method]
(Cold stretch resistance test)
About each synthetic artificial leather, after expanding and contracting 72 times -108% under the temperature condition of -10 degreeC 30,000 times, the surface state of the synthetic artificial leather was observed visually, and the following references | standards evaluated. The evaluation results are shown in Table 3.
○: No cracks Δ: Cracks occurred in 2 to 3 places ×: Many cracks occurred

(Abrasion resistance)
The wear resistance of each synthetic artificial leather was evaluated using a Gakushin type abrasion tester. Specifically, each synthetic artificial leather cut to a width of 1 cm was counted until the artificial leather was worn out when No. 6 canvas was repeatedly rubbed with a load of 1 kg. The evaluation results are shown in Table 3.

(Flexibility)
About the softness | flexibility of each synthetic artificial leather, the synthetic artificial leather of the reference example 1 was made into a reference | standard, it compared by the touch which touched with the hand, it determined by the following references | standards, and each evaluated. The evaluation results are shown in Table 3.
◎: Softer than the synthetic artificial leather of Reference Example 1 ○: Equivalent to the synthetic artificial leather of Reference Example 1 Δ: Slightly harder than the synthetic artificial leather of Reference Example 1 ×: Significantly compared to the synthetic artificial leather of Reference Example 1 hard

  The urethane prepolymer composition provided by the present invention is solvent-free without using an organic solvent or water, and is liquid at a temperature of at least 30 ° C. and can be handled at a temperature of 30 ° C. to 80 ° C. Because there are few restrictions on pot life and excellent workability, it is possible to omit the solvent evaporation and removal process, so energy consumption required for heating can be reduced and volatile organic substances are almost released into the atmosphere. Since it does not occur, it will be possible to provide environmentally friendly products, which are expected to be used in the future. The urethane prepolymer composition provided by the present invention is particularly useful for the production of synthetic artificial leather, and can be used as a material for forming the skin layer or as a combined material for forming the skin layer and the adhesive layer. Enables the production of synthetic artificial leather with low environmental impact. In addition, the synthetic artificial leather produced in this way is not inferior to the conventional one in terms of cold stretch resistance, wear resistance and flexibility, and in some cases has superior characteristics than the conventional one. It is expected to be used.

Claims (7)

It is a urethane prepolymer composition used by reacting a crosslinking agent with active hydrogen in the component to increase the molecular weight,
At least 20 to 80% by mass of a hydroxyl group-terminated urethane prepolymer having a hydroxyl value of 10 to 100 mgKOH / g,
The polymer medium contains 20 to 80% by mass of an oligomer having a hydroxyl value of 20 to 400 mg KOH / g and having no urethane bond, which can be crosslinked with the crosslinking agent, and
A urethane prepolymer composition having a substantially non-volatile content of 100% and being liquid at a temperature of at least 30 ° C.   The urethane prepolymer composition according to claim 1, wherein the hydroxyl-terminated urethane prepolymer is a reaction product of an oligomer, a glycol component, and an isocyanate compound.   The hydroxyl group-terminated urethane prepolymer has at least one of two or three functional groups per molecule, and the oligomer having no urethane bond has at least one of two or three functional groups per molecule. The urethane prepolymer composition according to 2.   It comprises 90 to 150 equivalent% of a polyisocyanate crosslinking agent having an NCO content of 5 to 35 mass% with respect to the average hydroxyl value of the urethane prepolymer composition according to any one of claims 1 to 3. A two-component coating agent characterized by that.   A synthetic artificial leather comprising a base material and a skin layer, wherein the skin layer is formed by the two-component coating agent according to claim 4.   A synthetic artificial leather comprising a base material, an adhesive layer, and a skin layer, wherein the adhesive layer and the skin layer are formed by the two-component coating agent according to claim 4.   The synthetic artificial leather according to claim 5 or 6, wherein an aqueous surface treatment agent is further applied to the surface of the skin layer.