Resin composition, molded article thereof, and transparent resin modifier

Abstract

To provide a polyurethane-containing acrylic resin composition and a molded article thereof in which reduction in transparency is suppressed, and which exhibit excellent mechanical properties such as impact resistance, particularly low-temperature impact resistance, and tensile properties, as well as a transparent resin modifier therefor.SOLUTION: A resin composition comprises a polyurethane containing a polyurethane structural unit (X) represented by formula (1) and a urea structural unit (Y) represented by formula (2), and a poly(meth)acrylate. A transparent resin modifier comprises this polyurethane.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyurethane-containing acrylic resin composition having excellent impact resistance, particularly low-temperature impact resistance, and mechanical properties such as tensile properties, and suppressing a decrease in transparency, a molded article thereof, and a transparent resin modifier therefor. [Background technology]

[0002] Acrylic resins, typified by polymethyl methacrylate, have excellent transparency and weather resistance, and molded articles made from them have beautiful appearances. As a result, they are widely used in a variety of applications, including signage, display items, lighting items, interior decoration items, building components, transportation equipment components, electronic equipment components, medical equipment components, and other equipment-related parts, as well as optical components, transportation-related parts, aquarium supplies, sanitary products, and amusement equipment.

[0003] However, acrylic resins have the drawback of poor impact resistance. Conventionally, in order to improve the impact resistance of acrylic resins, a method has been adopted in which diene rubbers containing butadiene as the main component are blended. In this case, although impact resistance is improved due to the excellent rubber elasticity of the butadiene rubber, it is known that weather resistance and heat resistance are deteriorated due to residual double bonds.

[0004] Polyurethanes are known as modifiers that maintain transparency in addition to weather resistance and low-temperature impact resistance. The physical properties of polyurethanes can be varied widely, from hard to soft, depending on the raw materials used. In particular, it is known that polyurethane rubbers with excellent elasticity, stretchability, durability, and abrasion resistance can be obtained by using polyol components with polymer segments whose glass transition temperatures are below room temperature, such as poly(tetramethylene oxide) diol and poly(ε-caprolactone) diol, as raw materials. Such polyurethane rubbers can be an effective source of rubber for improving the impact resistance of acrylic resins.

[0005] For example, Patent Document 1 proposes a method for producing an acrylic resin cast plate with excellent impact resistance by radically polymerizing a syrup-like mixture consisting of a monomer component whose main constituent is methyl methacrylate and polyurethane with alkenyl groups attached to both ends.

[0006] Furthermore, Patent Document 2 proposes a method for simultaneously improving impact resistance and heat distortion resistance by adding a low molecular weight crosslinking agent and a chain transfer agent such as a mercaptan to a polyurethane-containing syrup, or by adding a low molecular weight crosslinking agent to a polyurethane-containing syrup that has been prepolymerized and then curing the syrup.

[0007] The methods of Patent Documents 1 and 2 show that polyurethane is an effective rubber source for improving the impact resistance of the cured acrylic liquid syrup, but the impact resistance of the resulting cured product still does not reach a satisfactory level.

[0008] Patent Document 3 focuses on the molecular weight of polyurethane, and proposes that by using a modified polyurethane with a high molecular weight that is copolymerizable with an acrylic monomer, a phase-separated structure of the cured product is developed, thereby forming a morphology with a microphase-separated structure in which the polyurethane component and the acrylic component are dispersed at a level that allows transparency to be maintained. In Patent Document 3, in order to maintain transparency, the interface and morphology are controlled by copolymerization. This is because the refractive index of polyurethane is different from that of the acrylic resin, and is intended to suppress light scattering at the phase separation interface and by polyurethane fine particles. As a result, the amount of polyurethane that can be added is limited within the range where these controls are effective, which has led to problems such as a limit to the effect of adding polyurethane on improving impact resistance. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Special Publication No. 48-42956 [Patent Document 2] Japanese Patent Application Publication No. 3-54217 [Patent Document 3] Japanese Patent Application Publication No. 11-147988 Summary of the Invention [Problem to be solved by the invention]

[0010] In view of the above-mentioned problems of the conventional art, an object of the present invention is to provide a polyurethane-containing acrylic resin composition and molded article thereof which are excellent in impact resistance, particularly low-temperature impact resistance, and mechanical properties such as tensile properties, and which are inhibited from decreasing in transparency, as well as a transparent resin modifier therefor. [Means for solving the problem]

[0011] The present inventors have discovered that by introducing a specific urea structural unit into polyurethane, it is possible to adjust the refractive index of the polyurethane itself and provide a transparency modifier that is less restricted by interfaces and morphology. This eliminates restrictions on the amount that can be added to acrylic resins, allowing for greater freedom in resin composition and product design, and making it possible to provide resin compositions and molded articles thereof that meet a wide range of needs. The present invention was achieved based on these findings and is summarized as follows.

[0012] [1] A resin composition comprising a polyurethane containing a polyurethane structural unit (X) represented by the following formula (1) and a urea structural unit (Y) represented by the following formula (2), and a poly(meth)acrylate.

[0013] [ka]

[0014] (In formula (1), x and m are integers of 1 or more. R in formulas (1) and (2) is an aliphatic group which may have a substituent and which may contain a ring structure, or an aromatic group which may have a substituent. R' in formula (2) is an aliphatic group which may have a substituent and which may contain a ring structure, or an aromatic group which may have a substituent. R and R' may be the same or different.)

[0015] [2] The resin composition according to [1], wherein the content of the polyurethane in the resin composition is 1% by mass or more and less than 30% by mass.

[0016] [3] The resin composition according to [1] or [2], wherein the polyurethane is produced using an aliphatic dihydroxy compound and a dicarbamate compound represented by the following formula (3) as raw materials:

[0017] [ka]

[0018] (In the above formula (3), R 1 represents an aliphatic group which may have a substituent or an aromatic group which may have a substituent, R 2 represents an aliphatic group consisting of only carbon and hydrogen atoms or an aromatic group consisting of only carbon and hydrogen atoms.

[0019] [4] A molded article made of the resin composition according to any one of [1] to [3].

[0020] [5] A transparent resin modifier comprising a polyurethane containing a polyurethane structural unit (X) represented by the following formula (1) and a urea structural unit (Y) represented by the following formula (2):

[0021] [ka]

[0022] (In formula (1), x and m are integers of 1 or more. R in formulas (1) and (2) is an aliphatic group which may have a substituent and which may contain a ring structure, or an aromatic group which may have a substituent. R' in formula (2) is an aliphatic group which may have a substituent and which may contain a ring structure, or an aromatic group which may have a substituent. R and R' may be the same or different.) [Effects of the Invention]

[0023] According to the present invention, there are provided a polyurethane-containing acrylic resin composition and a molded article thereof which are excellent in impact resistance, particularly low-temperature impact resistance, and mechanical properties such as tensile properties, and which are inhibited from decreasing in transparency, and a transparent resin modifier therefor. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the present invention.

[0025] [Resin composition] The resin composition of the present invention is a resin composition containing a polyurethane (hereinafter sometimes referred to as the "polyurethane of the present invention") containing a polyurethane structural unit (X) represented by the following formula (1) (hereinafter sometimes simply referred to as the "polyurethane structural unit (X)") and a urea structural unit (Y) represented by the following formula (2) (hereinafter sometimes simply referred to as the "urea structural unit (Y)"), and a poly(meth)acrylate.

[0026] [ka]

[0027] (In formula (1), x and m are integers of 1 or more. R in formulas (1) and (2) is an aliphatic group which may have a substituent and which may contain a ring structure, or an aromatic group which may have a substituent. R' in formula (2) is an aliphatic group which may have a substituent and which may contain a ring structure, or an aromatic group which may have a substituent. R and R' may be the same or different.)

[0028] The polyurethane of the present invention contains the polyurethane structural unit (X) and the urea structural unit (Y), thereby suppressing a decrease in transparency and a decrease in tensile properties, and improving the impact resistance, particularly the low-temperature impact resistance, of the poly(meth)acrylate. Although the details of this mechanism are not clear, it is thought to be as follows. That is, impact resistance can be improved by blending a polyurethane with a poly(meth)acrylate. In this case, the polyurethane of the present invention contains urea structural units (Y) in addition to polyurethane structural units (X), and thus has excellent flexibility at low temperatures, and can suppress a decrease in tensile properties while improving low-temperature impact resistance, thereby enabling the improvement of these mechanical properties to be more effectively exerted. Furthermore, the refractive index of acrylic resins is about 1.49, but the polyurethane of the present invention containing the polyurethane structural unit (X) and the urea structural unit (Y) can also be controlled to a value close to the refractive index of this acrylic resin, for example, about 1.494 to 1.498, and the decrease in transparency due to the difference in refractive index can also be suppressed.

[0029] The polyurethane of the present invention may be a copolymer polyurethane containing polyurethane structural units (X) and urea structural units (Y), or a mixture of a polyurethane containing polyurethane structural units (X) but not containing urea structural units (Y) and a polyurethane containing urea structural units (Y) but not containing polyurethane structural units (X). Alternatively, the polyurethane may be a mixture of a polyurethane containing polyurethane structural units (X) and urea structural units (Y) and a polyurethane containing polyurethane structural units (X) but not containing urea structural units (Y) and / or a polyurethane containing urea structural units (Y) but not containing polyurethane structural units (X).

[0030] [Polyurethane] <Equation (1) and Equation (2)> First, formula (1) representing the polyurethane structural unit (X) contained in the polyurethane of the present invention and formula (2) representing the urea structural unit (Y) will be explained.

[0031] In the formula (1), from the viewpoint of availability of raw material monomers, x is preferably 7 or less, more preferably 5 or less, and even more preferably 3 or less. In particular, x is preferably 2 or 3. When x is within the above range, flexibility is obtained and a polyurethane with excellent impact resistance can be obtained.

[0032] In the formula (1), m is 1 or more, preferably 2 or more, more preferably 4 or more, and even more preferably 6 or more. On the other hand, from the viewpoint of the reactivity of the raw material monomers, m is preferably 100 or less, more preferably 80 or less, even more preferably 60 or less, and particularly preferably 40 or less. When m is equal to or less than the above upper limit, the compatibility between the raw material monomers during polyurethane production is good, and poor polymerization due to poor compatibility can be prevented.

[0033] In formula (1), x and m are integers of 1 or more, but when the polyurethane of the present invention contains two or more urethane structural units (X) with different x and m, x and m are their average values, including decimal points. Therefore, if the average values ​​of x and m are 1 or more and within the above-mentioned preferred ranges, they fall within the scope of the present invention.

[0034] R in formulas (1) and (2) and R′ in formula (2) are aliphatic groups which may have a substituent and may contain a ring structure, or aromatic groups which may have a substituent. Examples of the aliphatic group which may have a substituent R or R' and which may contain a ring structure include an alkylene group having 2 to 12 carbon atoms, an oxyalkylene group having 2 to 12 carbon atoms, a dioxyalkylene group having 3 to 12 carbon atoms, and a trioxyalkylene group having 4 to 12 carbon atoms. Examples of the aliphatic group which has a ring structure include a cycloalkylidene group having 3 to 10 carbon atoms. Examples of the substituents that these aliphatic groups may have include a halogen atom, a nitro group, a cyano group, an aryl group, an alkoxy group, an aryloxy group, a carboxylic acid group, an alkoxycarbonyl group, an acyl group, and an acyloxy group. Examples of the aromatic group of R and R' which may have a substituent include a phenylene group, a tolylene group, and a naphthylene group. Examples of the substituents that these aromatic groups may have include the above-mentioned aliphatic groups, halogen atoms, nitro groups, cyano groups, aryl groups, alkoxy groups, aryloxy groups, carboxylic acid groups, alkoxycarbonyl groups, acyl groups, and acyloxy groups.

[0035] R and R' may be the same or different, but the number of carbon atoms in R and R' is preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. On the other hand, the number of carbon atoms in R and R' is preferably 12 or less, more preferably 10 or less, and even more preferably 8 or less. When the carbon numbers of R and R' are within the above range, excellent compatibility is achieved.

[0036] From the viewpoint of compatibility, R and R' are each independently preferably an alkylene group having 2 to 12 carbon atoms, more preferably an alkylene group having 3 to 6 carbon atoms, and even more preferably an alkylene group having 4 to 6 carbon atoms.

[0037] The structure of the polyurethane of the present invention can be estimated by alkaline hydrolysis of the polyurethane to obtain a low molecular weight compound.

[0038] <Ratio of urethane structural unit (X) and urea structural unit (Y)> In the polyurethane of the present invention, the proportion of the urea structural unit (Y) in the total of the urethane structural unit (X) represented by the formula (1) and the urea structural unit (Y) represented by the formula (2) (hereinafter, sometimes referred to as the "urea abundance ratio") is preferably 1 mol % or more.

[0039] The proportion of urea in the polyurethane of the present invention is preferably 5 mol % or more, more preferably 10 mol % or more, and particularly preferably 15 mol % or more, and is preferably 75 mol % or less, more preferably 70 mol % or less, and even more preferably 65 mol % or less. When the ratio of urea is within the above range, the flexibility-imparting effect of the urethane structural unit (X) and the strength-improving effect of the urea structural unit (Y) can be effectively achieved at the same time, and the impact resistance of the poly(meth)acrylate can be improved while maintaining the tensile properties.

[0040] The inclusion of urea structural units (Y) can improve the tensile strength of the polyurethane itself, and when made into a transparent resin modifier described below, can improve the retention of tensile strength, etc. However, if the amount of urea structural units (Y) is greater than the above-mentioned upper limit, the torque during polymerization in the polyurethane production process may increase too much, making it difficult to sufficiently distill off by-product alcohols such as phenol from the system, or the viscosity may increase too much, making it difficult to mold the polyurethane at temperatures below the decomposition temperature of the urethane bond. The urea content of the polyurethane of the present invention can be measured by the method described in the Examples section below.

[0041] <Other structural units> The polyurethane of the present invention may contain other structural units, for example, structural units other than the urethane structural unit (X) and the urea structural unit (Y), i.e., urethane structural units other than the urethane structural unit (X) represented by the above formula (1), carbonate structural units, ester structural units, etc., as copolymerization components, within the scope of the present invention. However, when the polyurethane of the present invention contains other structural units, in order to reliably obtain the effects of the present invention due to the inclusion of the urethane structural units (X) and the urea structural units (Y), the polyurethane preferably contains 80 mol % or more of the urethane structural units (X) and the urea structural units (Y) in total, and more preferably 90 to 100 mol %, of all structural units contained in the polyurethane (100 mol %). Other structural units may also be contained as copolymerized polyurethanes with the polyurethane structural unit (X) and / or the urea structural unit (Y), or may be contained as a mixture with polyurethanes containing other structural units.

[0042] <Zero shear viscosity at 200°C> The zero shear viscosity of the polyurethane of the present invention at 200°C is preferably 2 Pa·s or more, more preferably 4 Pa·s or more. When the zero shear viscosity at 200°C is 2 Pa·s or more, good kneadability with poly(meth)acrylate can be obtained. On the other hand, the zero shear viscosity at 200°C is preferably 2000 Pa·s or less, more preferably 1500 Pa·s or less, and even more preferably 1000 Pa·s or less. When the zero shear viscosity at 200°C is equal to or less than the above upper limit, good kneadability with poly(meth)acrylate can be obtained. That is, the zero shear viscosity at 200°C is an index of the molecular weight in the present invention, and when this value is within a preferred range, the kneading properties are excellent.

[0043] The zero shear viscosity at 200°C of the polyurethane of the present invention can be measured by the method described in the Examples section below.

[0044] <Refractive index> From the viewpoint of obtaining a resin composition having excellent transparency, the refractive index of the polyurethane of the present invention is preferably close to the refractive index (1.49) of poly(meth)acrylate, and is preferably 1.490 to 1.500, particularly 1.494 to 1.498, as measured by the method described in the Examples section below. Polyurethanes with such refractive indexes can be obtained, for example, by introducing specific urea structural units into polyurethanes.

[0045] [Polyurethane manufacturing method] The method for producing the polyurethane of the present invention is not particularly limited, but it can be produced, for example, by reacting a compound having urethane bonds at both ends, called a dicarbamate (A), with a polyol (B) containing two or more hydroxy groups, and a diamine (C).

[0046] The reaction of dicarbamate (A) with polyol (B) extends the polymer chain with a urethane bond, while the reaction of dicarbamate (A) with diamine (C) extends the polymer chain with a urea bond. The ratio of polyol (B) to diamine (C) may be adjusted depending on productivity and the properties of the resulting polymer. By exposing dicarbamate (A) to high temperature conditions, the dicarbamate (A) can be decomposed to produce a diamine (diamine (C') used in producing dicarbamate (A)) in the reaction system. Therefore, by using the diamine produced from dicarbamate (A) as diamine (C), it is possible to eliminate the need for separately added diamine (C).

[0047] <Method for producing dicarbamate (A)> (Carbonate (D)) Dicarbamate (A) can be produced by reacting carbonate (D), which has substituents at both ends, with diamine (C') in solution. Changing the substituents on carbonate (D) can adjust the reactivity of dicarbamate (A), and changing the skeleton of diamine (C') can adjust the urethane-urea structure of the resulting polyurethane.

[0048] The reaction for producing dicarbamate (A) proceeds without the use of any additives to promote the reaction, but a heterocyclic monocyclic tertiary amine or a metal chloride may be used as a reaction promoter. Preferred examples of heterocyclic monocyclic tertiary amines include pyridine, 2-hydroxypyridine, α-, β-, and γ-picoline, imidazole, 2-methylimidazole, pyrazole, pyrazine, pyrimidine, and pyridazine. Examples of metal chlorides include magnesium chloride, lithium chloride, nickel chloride, zinc chloride, cupric chloride, iron chloride, tin chloride, cobalt chloride, and calcium chloride. These may be used alone or in combination.

[0049] Examples of the substituent of the carbonate (D) include an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and some of the hydrogen atoms of these substituents may be substituted with halogen. From the viewpoint of reactivity, the substituent is preferably an aromatic hydrocarbon group, and examples of such a carbonate (D) include diphenyl carbonate, di-o-tolyl carbonate, di-p-chlorophenyl carbonate, di-2,6-dimethylphenyl carbonate, and di-p-methoxyphenyl carbonate. Among these, diphenyl carbonate is particularly preferred from the viewpoint of reactivity.

[0050] Furthermore, with the increasing demand for carbon-neutral materials in recent years, the production process and raw material sources of carbonate (D) are also being reviewed. Therefore, in consideration of environmental impact and availability, carbonate (D) may be an aliphatic hydrocarbon-containing carbonate before substitution with an aromatic hydrocarbon group. In this case, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, etc. can be used. Furthermore, carbonate (D) may be a carbonate with different substituents at both ends, but cyclic carbonates such as alkylene carbonates are not preferred because hydroxy groups are formed at both ends, and therefore cannot be used as carbonate (D). Chain carbonates are used as carbonate (D). The carbonate (D) may be used alone or in combination of two or more kinds.

[0051] (Diamine(C)·Diamine(C')) The internal structure of the diamine (C') used to produce the dicarbamate (A), or the diamine (C) used as needed during polyurethane production, is preferably selected according to the required performance of the polyurethane to be produced. Generally, when aromatic diamines are used, mechanical properties such as rigidity and heat resistance can be imparted, but optical properties tend to be yellowish. Furthermore, when aliphatic diamines are used, mechanical properties such as flexibility and high extensibility and optical properties such as colorless transparency can be imparted. Two or more diamines may be used to achieve a balance between mechanical and optical properties. Furthermore, the diamine (C) and the diamine (C') may be the same or different. When the same diamine (C) and diamine (C') are used, a polyurethane in which R in the formulas (1) and (2) is the same as R' in the formula (2) is obtained. When different diamines (C) and (C') are used, polyurethanes in which R in the formulas (1) and (2) and R' in the formula (2) are different are obtained.

[0052] Representative examples of preferred diamines (C') and (C) include aromatic diamines such as 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,3'-dichloro-4,4'-diaminodiphenylmethane, and 3,3'-dimethoxy-4,4'-diaminodiphenylmethane, as well as aliphatic diamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine (1,6-diaminohexane), octamethylenediamine, and decamethylenediamine. Among these, aliphatic diamines are particularly preferred. To achieve high flexibility, diamines containing ether chains, which have weak hydrogen bonds and a low glass transition temperature, may be used. These diamines may be used alone or in combination of two or more.

[0053] <Polyol (B)> Examples of the polyol (B) include diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, etc. Depending on the application of the resulting polyurethane, trihydric alcohols such as trimethylolpropane, hexanetriol, and glycerin, polyether polyols, polyester polyols, and polycarbonate polyols may also be used. These polyols (B) may be used alone or in combination of two or more.

[0054] Among these, polyether polyols are preferred, and among these, polytrimethylene ether glycol and polytetramethylene ether glycol (PTMG) are preferred, with polytetramethylene ether glycol being particularly preferred. When polytrimethylene ether glycol is used, a urethane structural unit (X) in which x is 2 in the formula (1) is obtained. When polytetramethylene ether glycol is used, a urethane structural unit (X) in which x is 3 in the formula (1) is obtained.

[0055] When a polyether polyol such as PTMG is used, its number average molecular weight is preferably not more than 8,000, more preferably not more than 6,000, and even more preferably not more than 5,000. When the number average molecular weight of the polyether polyol such as PTMG is not more than the above upper limit, compatibility with the dicarbamate (A) is good, and poor polymerization due to poor compatibility can be prevented. On the other hand, there is no particular lower limit to the number average molecular weight of polyether polyols such as PTMG, but from the viewpoint of flexibility of the polymerized polymer, it is preferably 200 or more, particularly 400 or more. Here, the number average molecular weight is usually 1 It is measured by H-NMR, but for commercially available products, the product inspection value can be used. Therefore, m in the formula (1) is a number that satisfies such a number average molecular weight, and is particularly preferably 3 to 60, as described above.

[0056] <Urethane catalyst> A urethane catalyst may be used when reacting the dicarbamate (A) with the polyol (B). Urethane catalysts are broadly classified into amines and metals, with amines including diethylenetriamine, dimethylcyclohexylamine, and dimethylpyrelazine. Metals including tin chloride, dibutyltin oxide, dibutyltin dilaurate, tetrabutoxytitanium, lead octoate, magnesium chloride, lithium chloride, nickel chloride, zinc chloride, copper chloride, iron chloride, cobalt chloride, and calcium chloride. These urethane catalysts may be used alone or in combination of two or more.

[0057] Although the reaction can be accelerated by increasing the amount of urethane catalyst used, there is a risk that the catalytic activity per unit mass will decrease, side reactions will be accelerated, or the catalyst will remain in the resin, affecting the quality. From these viewpoints, the upper limit of the amount of urethane catalyst used relative to the raw material dicarbamate (A) is usually 10 mol%, preferably 5 mol%, and more preferably 1 mol%, and the lower limit is usually 0.01 μmol%, preferably 0.05 μmol%, and more preferably 0.1 μmol%.

[0058] <Polyurethane manufacturing method> The polyurethane of the present invention can be produced by a conventionally known polymerization method, and the polymerization method is not particularly limited. Examples of the polymerization method include solution polymerization and melt transesterification. Particularly preferred methods among these methods will be specifically described below.

[0059] Generally, in polycondensation, if the molar ratio of the reacting substituents is equal, the molecular weight will theoretically be at its maximum. However, in actual reactions, even if the molar ratio is matched, deviations can occur due to factors such as monomer decomposition and side reactions. In the case of isocyanates, which are widely used in polyurethanes, these include reactions with impurities such as water in polyols, and excessive consumption due to the generation of allophanate groups and biuret groups.

[0060] On the other hand, in the case of dicarbamate (A), heat causes carbon dioxide to escape from the urethane bond, generating an amine terminal and forming a urea bond.Urea bonds have weaker hydrogen bonds than urethane bonds, and as a result, they can exhibit crystallinity depending on the structure of the adjacent segments, making it possible to design a wider range of higher-order structures than polyurethane alone.

[0061] To actively introduce urea bonds, in addition to carrying out a polymerization reaction at a high temperature to generate amine in the system as described above, it is possible to add a diamine (C) as a monomer together with the polyol (B). The polycondensation method used in this case can be a known polymerization method, but melt polymerization may be carried out by heating above the melting point of each monomer and melting and stirring to react, or solution polymerization may be carried out by dissolving in a solvent. Melt polymerization is preferred from the viewpoint that a purification step after polycondensation is not required.

[0062] When the polyurethane of the present invention is produced using dicarbamate (A) and polyol (B) without adding a separate diamine (C), in order to achieve both the tensile strength and extensibility derived from the urethane structural unit (X) and the rigidity derived from the urea structural unit (Y), the upper limit of the amount of dicarbamate (A) used per mole of polyol (B) is typically 1.30 mol, preferably 1.25 mol, and more preferably 1.20 mol, and the lower limit is typically 0.70 mol, preferably 0.75 mol, and more preferably 0.80 mol per mole of polyol (B). If this molar ratio is too small, the resulting polyurethane will have many terminal OH groups, which tends to deteriorate the thermal stability of the resin. On the other hand, if this molar ratio is too large, the transesterification reaction rate will decrease, making it difficult to produce a polyurethane with the desired molecular weight, or the amount of dicarbamate (A) remaining in the resin will increase, which may cause odor during molding or when the molded product is formed.

[0063] On the other hand, when the polyurethane of the present invention is produced using dicarbamate (A), polyol (B), and diamine (C), for the same reasons as above, the upper limit of the amount of dicarbamate (A) used is usually 1.30 mol, preferably 1.25 mol, and more preferably 1.20 mol per 1 mol of the total of polyol (B) and diamine (C), and the lower limit is usually 0.70 mol, preferably 0.75 mol, and more preferably 0.80 mol per 1 mol of the total of polyol (B) and diamine (C). It is preferable to use the polyol (B) in an amount of 90 to 100 mol %, particularly 95 to 100 mol %, and the diamine (C) in an amount of 0 to 10 mol %, particularly 0 to 5 mol %, based on the total amount of the polyol (B) and the diamine (C).

[0064] In the melt transesterification method, the reaction temperature is not particularly limited, but is usually 100 to 250°C. The final pressure during the reaction is not particularly limited, but is usually a reduced pressure of 2 Torr or less. As a specific operation, the melt polycondensation reaction may be carried out under the above conditions while removing by-products.

[0065] The polyurethane of the present invention is significantly affected by heat history and oxidation, which can lead to a deterioration in color. Therefore, it is preferable to set the reaction temperature at 250°C or lower and to select reduced pressure conditions with a lower limit of about 0.05 Torr to prevent oxygen leakage from the equipment due to excessive reduced pressure.

[0066] The reaction can be carried out in either a batch or continuous manner. When carried out in a batch manner, the order in which the reaction substrates (reaction raw materials), catalyst, additives, etc. are mixed can be any order as long as the desired polyurethane is obtained, and an appropriate order can be set as desired.

[0067] In the production of the polyurethane of the present invention, the reaction temperature during polycondensation is important in controlling the abundance ratio of urea in the polyurethane of the present invention and the molecular weight (as mentioned above, the molecular weight of the polyurethane of the present invention is indicated by the zero shear viscosity at 200°C). It is preferable to adjust the reaction temperature, along with the molar ratio of the raw materials charged, depending on the abundance ratio and molecular weight of urea in the target polyurethane.

[0068] [One embodiment of a method for producing polyurethane] An example of an embodiment of the method for producing a polyurethane of the present invention will be given below, but the method for producing a polyurethane of the present invention is not limited to the following method in any way.

[0069] The polyurethane of the present invention can be produced, for example, by reacting a compound having urethane bonds at both ends, which is a dicarbamate compound represented by the following formula (3) (hereinafter, may be referred to as "dicarbamate compound (3)"), with an aliphatic dihydroxy compound.

[0070] [ka]

[0071] (In the above formula (3), R 1 represents an aliphatic group which may have a substituent or an aromatic group which may have a substituent, R 2 represents an aliphatic group consisting of only carbon and hydrogen atoms or an aromatic group consisting of only carbon and hydrogen atoms.

[0072] <Dicarbamate compound (3)> R in formula (3) represents the dicarbamate compound (3) used as a raw material for producing the polyurethane of the present invention. 1 has the same meaning as R' or R in the formula (2), and therefore the explanation thereof will be omitted. Also, R 2Examples of the aliphatic group consisting of only carbon atoms and hydrogen atoms include alkyl groups having 1 to 12 carbon atoms. Examples of the substituent that these aliphatic groups may have include alkyl groups having 1 to 12 carbon atoms. R 2 Examples of the aromatic group consisting of only carbon atoms and hydrogen atoms include a phenyl group, a tolyl group, a naphthyl group, etc. Examples of the substituent that these aromatic groups may have include the above-mentioned aliphatic groups and halogen atoms.

[0073] R 1 From the viewpoint of compatibility, the alkylene group is preferably a linear alkylene group having 2 to 12 carbon atoms, more preferably a linear alkylene group having 3 to 6 carbon atoms, and even more preferably a linear alkylene group having 4 to 6 carbon atoms. R 2 From the viewpoint of reactivity, a methyl group, an ethyl group, or a phenyl group is preferred.

[0074] As described above, such a dicarbamate compound (3) can be obtained by reacting a carbonate compound (dicarbamate (A)) having a substituent at its terminal with a diamine compound (diamine (C')) in a solution.

[0075] <Aliphatic dihydroxy compounds> Examples of the aliphatic dihydroxy compound that can be used include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and butylene glycol, as well as polyether polyols, polyester polyols, and polycarbonate polyols. Among these, polyether polyols are preferred, and polytrimethylene ether glycol (x=2) or polytetramethylene ether glycol (x=3) represented by the following formula (4) are particularly preferred from the viewpoint of compatibility with the dicarbamate compound (3), with polytetramethylene ether glycol (PTMG) being particularly preferred.

[0076] [ka]

[0077] (In the above formula (4), x and m have the same meanings as in the above formula (1), but preferably x is an integer of 2 or 3, and m is preferably an integer of 1 to 500, more preferably 3 to 60.)

[0078] The number average molecular weight (or molecular weight) of the aliphatic dihydroxy compound is preferably not more than 8,000, more preferably not more than 6,000, and particularly preferably not more than 5,000. When the number average molecular weight of the aliphatic dihydroxy compound is not more than the upper limit, compatibility with the dicarbamate compound (3) is good, and polymerization failure due to poor compatibility can be prevented. On the other hand, in the case of polyether polyols and the like, there is no particular lower limit to the number average molecular weight, but from the viewpoint of the flexibility of the resulting polymer, it is preferably 200 or more, particularly 400 or more. 1 Although this is a value measured by H-NMR, for commercially available products, product inspection values ​​can be used. Therefore, m in the formula (4) is preferably a number that satisfies this number-average molecular weight. Generally, polyether polyols and the like are provided as a mixture of compounds with different m in the formula (4). In this case, the value of m is shown as an average value and is not necessarily an integer, but in a single compound, m is preferably an integer between 1 and 500.

[0079] The above aliphatic dihydroxy compounds may be used alone or in combination of two or more.

[0080] As mentioned above, depending on the intended use of the polyurethane, a trihydric alcohol such as trimethylolpropane, hexanetriol, or glycerin may be used in combination with the above aliphatic dihydroxy compound.

[0081] <Polyurethane manufacturing method> As described above, the melt polymerization method can also be used as a method for producing polyurethane in one embodiment of the present invention. The melt polymerization method does not use solvents or highly toxic compounds, so it can reduce the environmental impact and is also excellent in productivity and quality stability.

[0082] When producing polyurethane by melt polymerization, the starting compounds, dicarbamate compound (3) and aliphatic dihydroxy compound, are melted and mixed, preferably in the presence of the aforementioned urethane catalyst, and the degree of polymerization is increased while removing elimination components from the system. Toward the end of the polymerization, the reaction is continued under high temperature and high vacuum conditions until the desired molecular weight is achieved. Once the reaction is complete, the molten resin is removed from the reactor, yielding the polyurethane of the present invention.

[0083] The polymer chain elongates when a dicarbamate compound (3) undergoes a transesterification reaction with an aliphatic dihydroxy compound. Generally, in polycondensation, the molecular weight is theoretically maximized when the molar ratio of the reacting substituents is equal. However, in actual reactions, even if the molar ratio is matched, deviations can occur due to monomer decomposition and side reactions.

[0084] Furthermore, it is important to properly control the balance between temperature and pressure in the reaction system. If either the temperature or pressure is changed too quickly, unreacted monomers may be distilled out of the reaction system. As a result, the molar ratio of the aliphatic dihydroxy compound to the dicarbamate compound (3) may change, and a polyurethane with the desired molecular weight may not be obtained.

[0085] The molar ratio of the dicarbamate compound (3) to the aliphatic dihydroxy compound to be reacted is preferably 0.70 or more, more preferably 0.75 or more, and even more preferably 0.80 or more, and is preferably 1.30 or less, more preferably 1.25 or less, and even more preferably 1.20 or less.

[0086] A method for producing a polyurethane according to one embodiment of the present invention is carried out in two or more multi-stage steps. The polymerization reaction may be carried out in two or more stages using one polymerization reactor by sequentially changing the reaction conditions, or in two or more stages using two or more reactors by changing the conditions for each reactor. It is believed that a multi-stage polymerization method using two or more stages allows the polycondensation reaction to proceed smoothly, resulting in a higher molecular weight polymer. As a result, it is possible to obtain a polyurethane that is flexible and has both excellent tensile strength and tensile elongation.

[0087] The first reaction step according to one embodiment of the present invention is a step in which an aliphatic dihydroxy compound and a dicarbamate compound (3) are reacted under stepwise reduced pressure conditions of from normal pressure to 1000 Pa. As used herein, "normal pressure" refers to a pressure of 101.3 kPa. Furthermore, as used herein, "reacting" refers to mixing raw materials and subjecting them to reaction conditions. After mixing, the raw materials may be stirred. Here, "reducing the pressure stepwise" includes cases where the pressure continues to decrease linearly during the reaction process, a stepwise decrease, a temporary increase in pressure followed by a subsequent decrease in pressure, etc. The pressure reduction may be uniform or uneven.

[0088] In the first-stage reaction step, a monohydroxy compound, which is a by-product of the reaction between an aliphatic dihydroxy compound and a dicarbamate compound (3), is distilled out of the reaction system. At this time, by gradually reducing the pressure, effects such as suppressing the distillation of unreacted monomers can be obtained. On the other hand, for example, if the first-stage reaction step is carried out at atmospheric pressure, the reaction time increases, which not only results in a waste of energy costs but also may increase side reactions. Furthermore, if the pressure is suddenly reduced in the first-stage reaction step, unreacted monomers are distilled off, which may result in failure to obtain the desired polymer or copolymer.

[0089] Specifically, the following reaction conditions can be adopted in the first reaction step. That is, the internal temperature of the polymerization reactor is preferably 80°C or higher, more preferably 100°C or higher, and even more preferably 120°C or higher. If the reaction temperature condition is below this lower limit, the monomer may not melt and the reaction may not proceed. On the other hand, since urethane bonds decompose at high temperatures, the reaction temperature is preferably 280°C or lower, more preferably 260°C or lower, and even more preferably 240°C or lower. The final pressure of the polymerization reactor (hereinafter, "pressure" refers to absolute pressure) is preferably 1500 Pa or more, more preferably 2000 Pa or more. Setting the pressure at or above the lower limit prevents the distillation of monomers in the early stage of the reaction, and allows the production of a polymer with a high degree of polymerization. On the other hand, the upper limit of the final pressure is preferably 30 kPa or less, particularly 15 kPa or less, in order to distill off the monohydroxy compound. The reaction time of the first-stage reaction step is preferably 15 to 240 minutes. By setting the reaction time to the above-mentioned lower limit or more, it is possible to promote the production of oligomers and prevent the distillation of monomers in the second-stage reaction step. Furthermore, by setting the reaction time to the above-mentioned upper limit or less, it is possible to prevent unintended side reactions and obtain a polymer with little coloration. The reaction time is preferably less than 240 minutes, more preferably less than 180 minutes, and even more preferably less than 120 minutes.

[0090] In the reaction of the first stage reaction step, the lower the vacuum pressure, the more the polymerization reaction can be accelerated, but on the other hand, the amount of unreacted monomer distilled increases. In order to simultaneously suppress the distillation of unreacted monomer and accelerate the reaction by reducing the pressure, it is effective to use a reactor equipped with a reflux condenser. The use of a reflux condenser is particularly effective in the early stages of the reaction when there is a large amount of unreacted monomer.

[0091] Following the first-stage reaction step, the second-stage reaction step is a step in which the reaction product obtained in the first-stage reaction step is reacted under conditions in which the final pressure is 1000 Pa or less, preferably 500 Pa or less and 5 Pa or more. In the second-stage reaction step, the vacuum pressure is gradually reduced, and the polymerization reaction is allowed to proceed to the desired molecular weight while the by-product monohydroxy compound is continuously removed from the reaction system. The internal temperature in the second-stage reaction step may be the same as the internal temperature in the first-stage reaction step, or may be higher or lower. The final internal temperature is preferably 80°C or higher, more preferably 100°C or higher, and even more preferably 120°C or higher. On the other hand, it is preferably 280°C or lower, more preferably 260°C or lower, and even more preferably 240°C or lower. By setting the reaction temperature at or above the lower limit, the by-product monohydroxy compound can be efficiently removed from the reaction system. On the other hand, by setting the reaction temperature at or below the upper limit, coloration and decomposition of the resulting polymer can be prevented. In the second-stage reaction step, a reduced pressure of 1000 Pa or lower is not particularly problematic, but the final vacuum pressure is preferably 1000 Pa or lower, more preferably 500 Pa or lower, and even more preferably 300 Pa or lower, in order to remove residual low-molecular-weight compounds from the polymer.

[0092] The reaction time of the second-stage reaction step is preferably within 15 to 240 minutes. By setting the reaction time to the above-mentioned lower limit or more, the monohydroxy compound by-produced up to the second-stage reaction step can be efficiently removed from the reaction system. Furthermore, by setting the reaction time to the above-mentioned upper limit or less, coloration and decomposition of the polymer can be prevented.

[0093] The total reaction time of the first and second reaction steps is preferably less than 480 minutes, more preferably less than 360 minutes, and even more preferably less than 240 minutes, in order to prevent coloration and decomposition of the resulting polymer. In addition, the total reaction time of the first and second reaction steps is preferably 30 minutes or more in terms of yield, etc.

[0094] Once it is confirmed that the specified melt viscosity (molecular weight) has been reached using the stirring power as an indicator, nitrogen is introduced into the reactor to return the pressure to normal pressure and stop the polymerization reaction. In the case of a continuous system, the polymerization reaction is stopped by continuously withdrawing the molten resin from the reactor and cooling it.

[0095] The molten resin is discharged from the die head in the form of strands, cooled and solidified, and pelletized using a rotary cutter or the like. If necessary, extrusion devolatilization, extrusion kneading, and extrusion filtration may be performed before pelletization. In these steps, additives may be mixed into the resin, low-molecular-weight components may be devolatilized using a vacuum vent, or foreign matter may be removed using a polymer filter.

[0096] According to the method for producing a polyurethane according to one embodiment of the present invention, the ratio of urea present in the produced polyurethane can be changed as desired by controlling the reaction temperature in the second reaction step. For example, the proportion of urea can be increased by setting the reaction temperature higher or lower than 200°C.

[0097] <Poly(meth)acrylate (PMMA)> The poly(meth)acrylate contained in the resin composition of the present invention and the method for producing the same are not particularly limited. In addition, commercially available poly(meth)acrylates can also be used. Commercially available poly(meth)acrylate products include, for example, Acrypet. TM (Mitsubishi Chemical Corporation).

[0098] <Other ingredients> The resin composition of the present invention may contain other components in addition to the polyurethane and poly(meth)acrylate, as needed, as long as the desired physical properties are not significantly impaired. Examples of other components include polyurethane resins not containing the aforementioned urethane structural unit (X) and urea structural unit (Y), resins other than poly(meth)acrylate, and various resin additives. Resins other than the polyurethane and poly(meth)acrylate of the present invention may be contained as copolymer components with the poly(meth)acrylate, or may be mixed with the poly(meth)acrylate.

[0099] Examples of resins other than polyurethane and poly(meth)acrylate include thermoplastic polyester resins such as polyethylene terephthalate resin, polytrimethylene terephthalate resin, and polybutylene terephthalate resin; styrene-based resins such as polystyrene resin, high impact polystyrene resin (HIPS), acrylonitrile-styrene copolymer (AS resin), acrylonitrile-styrene-acrylic rubber copolymer (ASA resin), and acrylonitrile-ethylene propylene rubber-styrene copolymer (AES resin); polyolefin resins such as polyethylene resin and polypropylene resin; polyamide resin; polyimide resin; polyetherimide resin; polycarbonate resin; polyphenylene ether resin; polyphenylene sulfide resin; polysulfone resin; polyvinyl chloride resin, etc. These resins may be contained alone or in any combination and ratio of two or more.

[0100] Examples of resin additives include heat stabilizers, antioxidants, mold release agents, light-resistant agents (HALS), flame retardants, antistatic agents, antifogging agents, lubricants, antiblocking agents, flow improvers, plasticizers, dispersants, antibacterial agents, dyes, pigments, etc. One type of resin additive may be contained, or two or more types may be contained in any combination and ratio.

[0101] [Content in resin composition] The content of the polyurethane of the present invention in the resin composition of the present invention is preferably 1% by mass or more and less than 30% by mass. When the content of the polyurethane of the present invention is 1% by mass or more, the inclusion of the polyurethane of the present invention can effectively improve mechanical properties such as impact resistance, particularly low-temperature impact resistance and tensile properties. On the other hand, when the content of the polyurethane of the present invention is less than 30% by mass, a resin composition with excellent transparency can be obtained. From these viewpoints, the content of the polyurethane of the present invention in the resin composition of the present invention is more preferably 2% by mass or more, more preferably 20% by mass or less, and even more preferably 10% by mass or less. As described above, the polyurethane of the present invention can adjust the refractive index of the polyurethane itself by introducing a specific urea structural unit, thereby suppressing a decrease in transparency due to differences in refractive index. Therefore, good effects can be exhibited over a wide range of content, from 1% by mass to less than 30% by mass, and one of its features is that it offers a high degree of freedom in resin composition and product design.

[0102] The content of poly(meth)acrylate in the resin composition of the present invention may be the remainder other than the polyurethane of the present invention in 100% by mass of the resin composition, but is usually preferably in the range of 70 to 99% by mass, or 80 to 99% by mass. If the content of poly(meth)acrylate is equal to or greater than the above lower limit, the transparency, weather resistance, and good appearance of the poly(meth)acrylate can be effectively obtained, and if it is equal to or less than the above upper limit, the contents of the polyurethane of the present invention and other components blended as necessary can be ensured, and a resin composition excellent in various physical properties can be obtained.

[0103] [Method of producing resin composition] The method for producing the resin composition of the present invention is not particularly limited, but examples thereof include the following methods 1) and 2). 1) A method of melt-kneading the polyurethane of the present invention with a poly(meth)acrylate 2) A method of melt-kneading the polyurethane of the present invention in a molten state with a poly(meth)acrylate in a molten state.

[0104] Each method will be explained below.

[0105] 1) A method of melt-kneading the polyurethane of the present invention with a poly(meth)acrylate Pellets or powder of the polyurethane of the present invention and pellets or powder of the poly(meth)acrylate are melt-kneaded using a mixing device such as a kneader, twin-screw extruder, or single-screw extruder. The polyurethane pellets or powder of the present invention and the poly(meth)acrylate pellets or powder may be mixed in solid state beforehand and then melt-kneaded. Alternatively, one of the two may be melted first in the mixing device, and the other resin may be added thereto and melt-kneaded. The temperature during melt-kneading is not particularly limited, but is preferably 140°C or higher, more preferably 160°C or higher, and even more preferably 180°C or higher. Also, it is preferably 300°C or lower, more preferably 280°C or lower, and even more preferably 260°C or lower. By maintaining the melt-kneading temperature at or above the lower limit, the polyurethane of the present invention and the poly(meth)acrylate are thoroughly mixed, thereby reducing variations in hardness and impact resistance when a molded product is produced. Furthermore, maintaining the melt-kneading temperature at or below the upper limit prevents deterioration in the color tone of the resulting resin composition.

[0106] 2) A method of melt-kneading the polyurethane of the present invention in a molten state with a poly(meth)acrylate in a molten state. The polyurethane of the present invention in a molten state and the poly(meth)acrylate in a molten state are mixed using a mixing device such as a stirring tank, static mixer, kneader, twin-screw extruder, single-screw extruder, etc. In this case, if the polyurethane is obtained by, for example, a melt transesterification method, it may be introduced into the mixing device in a molten state without being cooled and solidified.

[0107] In producing the resin composition of the present invention, in any of the above methods, pigments, dyes, release agents, heat stabilizers, etc. can be added as needed within the range that does not impair the object of the present invention. In addition, the order of mixing the components is not particularly limited.

[0108] [Physical properties of resin composition] <Light transmittance of resin composition> The transmittance of the resin composition of the present invention at a wavelength of 400 nm is preferably 70% or more, more preferably 75% or more, when the thickness is 1 mm. If the transmittance is equal to or higher than the lower limit, the finished product will have excellent aesthetic appearance. The transmittance of light at a wavelength of 400 nm of the resin composition of the present invention is measured by the method described in the Examples section below.

[0109] <-40°C Izod impact strength of resin composition> The -40°C Izod impact strength of the resin composition of the present invention is preferably 1.01 or more, more preferably 1.03 or more, and even more preferably 1.05 or more, relative to the -40°C Izod impact strength of the poly(meth)acrylate alone. If this value is equal to or greater than the above lower limit, the resin composition has excellent low-temperature impact resistance and can be used in applications that could not be applied to poly(meth)acrylate alone. The -40°C Izod impact strength of the resin composition of the present invention is measured by the method described in the Examples section below.

[0110] <Tensile modulus of resin composition> The tensile modulus of the resin composition of the present invention is not particularly limited, but from the viewpoint of mechanical strength, it is preferably 300 MPa or more, more preferably 310 MPa or more, and even more preferably 315 MPa or more. The tensile modulus of the resin composition of the present invention is measured by the method described in the Examples section below.

[0111] [Molded product] The molded article of the present invention is obtained by using the resin composition of the present invention. A conventional extrusion molding machine or injection molding machine is used to produce the molded article from the resin composition of the present invention.

[0112] The molding temperature when molding the resin composition of the present invention is preferably 140°C or higher, more preferably 160°C or higher, and even more preferably 180°C or higher. It is also preferably 300°C or lower, more preferably 280°C or lower, and even more preferably 260°C or lower. If the molding temperature is too low, the melt viscosity may increase, reducing fluidity and moldability. If the molding temperature is too high, the polyurethane in the resin composition may become discolored, which may adversely affect the color tone of the resulting molded product, which is undesirable. Furthermore, polyurethane may decompose at high temperatures.

[0113] When injection molding or extrusion molding is carried out, additives may be added to the resin composition of the present invention as appropriate within the range that does not impair the object of the present invention. Examples of such additives that can be used include known additives such as foam stabilizers, antioxidants, defoamers, abrasive grains, fillers, pigments, dyes, colorants, thickeners, surfactants, flame retardants, plasticizers, lubricants, antistatic agents, heat stabilizers, tackifiers, curing catalysts, stabilizers, silane coupling agents, and waxes. Furthermore, if necessary, conventionally known thermoplastic resins, thermosetting resins, and the like can be appropriately selected and used as blending resins within the scope of the present invention. The above-mentioned additives are merely examples, and the type and amount of use are not particularly limited as long as they do not impair the objectives of the present invention.

[0114] [Application] The resin composition of the present invention and molded articles thereof have excellent transparency and low-temperature impact resistance, and can therefore be used in a variety of fields, including civil engineering and construction and the automotive industry.

[0115] [Transparent resin modifier] The transparent resin modifier of the present invention contains a polyurethane containing a polyurethane structural unit (X) represented by the following formula (1) and a urea structural unit (Y) represented by the following formula (2).

[0116] [ka]

[0117] (In formula (1), x and m are integers of 1 or more. R in formulas (1) and (2) is an aliphatic group which may have a substituent and which may contain a ring structure, or an aromatic group which may have a substituent. R' in formula (2) is an aliphatic group which may have a substituent and which may contain a ring structure, or an aromatic group which may have a substituent. R and R' may be the same or different.)

[0118] That is, the transparent resin modifier of the present invention corresponds to the polyurethane of the present invention described above, and its suitable composition, physical properties, etc. are as explained in the section on the polyurethane of the present invention.

[0119] The transparent resin modifier of the present invention can be used as a resin modifier for improving mechanical properties such as impact resistance, particularly low-temperature impact resistance and tensile properties, without impairing transparency, by adding and mixing it in an appropriate ratio with the poly(meth)acrylate and other resins described above as those that can be contained in the resin composition of the present invention. [Example]

[0120] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to the following examples.

[0121] [Measurement and evaluation method] The physical properties of the polyurethanes produced in the following examples and the resin compositions obtained in the examples and comparative examples were measured and evaluated by the following methods.

[0122] (1) Urea content in polyurethane Surface IR was performed by ATR (attenuated total reflection) using a diamond cell with a Fourier transform infrared spectrophotometer FT / IR-4600 (manufactured by JASCO Corporation). A piece of resin is sandwiched between the diamond cells, and the measurement range is 4000 to 400 cm. -1 , resolution: 2cm -1 The measurement was carried out with 32 accumulations. Multivariate analysis was performed on the obtained peaks, and the peaks at 1731, 1721, 1704, and 1694 cm -1 The peaks at 1685, 1676, 1671, and 1663 cm are derived from the urethane structure (X). -1 The peaks were resolved as peaks derived from the urea structural unit (Y). The abundance ratio of urea was calculated based on the area ratio of these peaks.

[0123] (2) Zero shear viscosity of polyurethane Using a rheometer DHR-3 (manufactured by TA Instruments), aluminum parallel plates with a diameter of 25 mm were used, and the angular frequency was varied from 628 to 2.50 × 10 under the conditions of a test temperature of 200°C and a strain of 1%. -3Measurements were taken while changing the frequency range in rad / s, and the value at which it was determined that the complex viscosity value became constant on the low frequency side was taken as the zero shear viscosity.

[0124] (3) Refractive index of polyurethane The resulting polyurethane was dried for at least 3 hours in a vacuum dryer set at 50-80°C, and then pressed into a 1 mm thick piece using a heat press at a temperature of 80-210°C. This pressed piece was then cut into a 1 mm thick piece approximately 6 mm long and 6 mm wide using a dumbbell cutter and then scissors. The resulting test sample was measured using a Kalnew Precision Refractometer KPR-2000 (Shimadzu Corporation) at a wavelength of 587 nm using the d-line of a helium lamp. 6 nm).

[0125] (4) Manufacturing of kneaded resin samples Acrypet TM (Mitsubishi Chemical Corporation, Grade: MF001) and each polyurethane were dried for more than 3 hours in a vacuum dryer set at 80°C. The two were mixed in the specified ratio, and a total of 18 g was kneaded in a small kneader (Leo Labo) at a temperature of 220-230°C for 3 minutes.

[0126] (5) Transparency of the resin composition The resulting kneaded resin (Acrypet in Comparative Example 1) TM The sample (only) was molded in an injection molding machine (manufactured by Leo Labo) under conditions of injection pressure of 0.60-0.80 MPa, injection zone temperature of 220-230°C, and mold temperature of 70°C to obtain a flat test sample with a thickness of 1 mm. The obtained test sample was measured for light transmittance at a wavelength of 400 nm in the thickness direction using a recording spectrophotometer U-4000 (manufactured by Hitachi High-Technologies Corporation). A higher value indicates better transparency.

[0127] (6) -40°C Izod impact strength of resin composition The resulting kneaded resin (Acrypet in Comparative Example 1) TMThe sample (only) was molded in an injection molding machine (manufactured by Leo Labo) under conditions of injection pressure 0.60-0.80 MPa, injection zone temperature 220-230°C, and mold temperature 70°C to obtain a strip-shaped test sample 4 mm thick and 10 mm wide. The obtained test sample was cooled in a thermostatic bath at -40°C. The Izod impact strength of the sample immediately after cooling, measured at a temperature of 23°C and humidity of 50%, was taken as the -40°C Izod impact strength. Higher values ​​indicate better low-temperature impact resistance.

[0128] (7) Tensile modulus of resin composition The resulting kneaded resin (Acrypet in Comparative Example 1) TM The samples (only) were dried for at least 3 hours in a vacuum dryer set at 50-80°C, and then pressed in a heat press at a temperature of 80-210°C to produce 1 mm thick pressed pieces. These pressed pieces were cut with a dumbbell cutter into strips 1 mm thick, 60-65 mm long, and 9 mm wide to obtain test samples. Tensile tests were performed on the obtained test samples using a universal testing machine STB-1225L (manufactured by A&D Co., Ltd.) with an initial chuck distance of 20 mm and a tensile speed of 300 mm / min. The initial displacement in the strain-stress curve during the test was taken as the tensile modulus. A higher value indicates better mechanical strength.

[0129] [raw materials] The compounds used in the following Examples and Comparative Examples are abbreviated as follows: The compounds used were manufactured by the following manufacturers.

[0130] <Diol compounds> PTMG650: Polytetramethylene ether glycol, number average molecular weight approximately 650 (Fujifilm Wako Pure Chemical Industries, Ltd.) PO3G500: Polytrimethylene ether glycol, number average molecular weight approximately 500 (Sigma-Aldrich)

[0131] <Carbonate compounds> DPC: Diphenyl carbonate (Sigma-Aldrich)

[0132] <Diamine compounds> HMDA: 1,6-diaminohexane (Tokyo Chemical Industry Co., Ltd.)

[0133] <Solvent> Dichloromethane (Fujifilm Wako Pure Chemical Industries, Ltd.) Tetrahydrofuran (Fujifilm Wako Pure Chemical Industries, Ltd.) Hexane (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0134] <Polymerization catalyst> Tin(II) chloride dihydrate (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0135] [Example 1] <Synthesis of dicarbamate> Under a nitrogen atmosphere, DPC (128 g) and dichloromethane (145 mL) were added to a reaction vessel and stirred in an ice bath. Next, a solution of HMDA (34.9 g) and dichloromethane (105 mL) was added dropwise over 10 minutes. After the addition was complete, the ice bath was removed and the mixture was stirred at room temperature for 2 hours, after which stirring was stopped. The reaction solution was concentrated, and then tetrahydrofuran (200 mL) was added, followed by hexane (200 mL). The resulting precipitate was washed with a mixture of tetrahydrofuran (300 mL) and hexane (300 mL) and then filtered under suction. The resulting solid was transferred to a metal tray and dried under reduced pressure at 50°C for 9 hours, yielding 88.1 g (82% yield) of dicarbamate 1 as a white solid.

[0136] <Production of polyurethane> A raw material mixture was prepared by adding 51.82 g (145 mmol) of dicarbamate 1 obtained in Synthesis Example 1, 80.03 g (138 mmol) of PO3G500, and 0.1661 g (0.738 mmol) of tin(II) chloride dihydrate as a catalyst to a glass reactor having an internal volume of approximately 570 mL and equipped with a reactor stirrer, a reactor heating device, and a reactor pressure adjusting device, such that the amount of tin(II) chloride dihydrate was 2.6 mmol per 1 mole of the total of dicarbamate 1 and PO3G500.

[0137] Next, the pressure inside the glass reactor was reduced to approximately 200 Pa, and then the pressure was returned to atmospheric pressure with nitrogen. This operation was repeated three times to purge the inside of the reactor with nitrogen. After nitrogen purge, the external temperature of the reactor was increased to 160°C, and the internal temperature of the reactor was gradually increased to dissolve the mixture. The agitator was then rotated at 100 rpm. Then, the pressure inside the reactor was reduced from 101.3 kPa (760 Torr) to 4000 Pa (30 Torr) absolute over 45 minutes, while distilling off phenol, which was by-produced in the oligomerization reaction of the polyether polyol compound and dicarbamate 1 inside the reactor.

[0138] Next, the pressure inside the reactor was maintained at 4000 Pa, and the temperature outside the reactor was raised to 220°C over 15 minutes while further distilling off phenol. The pressure inside the reactor was then reduced from 4000 Pa (30 Torr) to 400 Pa (3 Torr) absolute over a further 30 minutes, and the distilled phenol was removed from the system. The absolute pressure inside the reactor was then reduced to approximately 100 Pa (approximately 0.75 Torr), and the polycondensation reaction was carried out. The rotation speed of the agitator was reduced over the course of the reaction, and the polycondensation reaction was terminated when the agitator in the reactor reached a predetermined stirring power.

[0139] The pressure inside the reactor was then restored to 101.3 kPa absolute with nitrogen, and then increased to 108.0 kPa absolute, and polyurethane was withdrawn in the form of strands from the bottom of the reactor to obtain polyurethane strands. The polyurethane thus obtained was mixed with the above-mentioned procedure to obtain a kneaded resin sample, which was then subjected to various evaluations. The results are shown in Table 1.

[0140] [Example 2] Polyurethane was produced in the same manner as in Example 1, and polyurethane and ACRYPET were mixed. TM The same procedure was carried out except that the mixing ratio of was changed as shown in Table 1. The evaluation results are shown in Table 1.

[0141] [Example 3] A polyurethane was produced in the same manner as in Example 1, except that 89.98 g of PTMG650 was used instead of PO3G500, the amount of dicarbamate 1 used was 40.01 g, and the amount of tin(II) chloride dihydrate used was 0.1589 g. The polyurethane thus obtained was mixed with the above-mentioned procedure to obtain a kneaded resin sample, which was then subjected to various evaluations. The results are shown in Table 1.

[0142] [Comparative Example 1] Acrypet TM (Grade: MF001) was evaluated using the above procedures. The results are shown in Table 1.

[0143] Comparative Example 2 As polyurethane, BASF's "Elastollan NY1197A" which does not contain urea structural units (Y) was used, and this was mixed with Acrypet in the mixing ratio shown in Table 1. TM The resin composition obtained by mixing the above was evaluated according to the above procedures. The results are shown in Table 1.

[0144] Comparative Example 3 As polyurethane, BASF's "Elastollan NY585" which does not contain urea structural units (Y) was used, and this was mixed with Acrypet in the mixing ratio shown in Table 1. TM The resin composition obtained by mixing the above was evaluated according to the above procedures. The results are shown in Table 1.

[0145] [Table 1]

[0146] As is clear from Table 1, the resin compositions of Examples 1 to 3, which are resin compositions of the present invention in which the polyurethane of the present invention is mixed with poly(meth)acrylate, have excellent low-temperature impact resistance while suppressing the decrease in tensile modulus and transparency to a certain extent compared to Comparative Example 1, which contains poly(meth)acrylate alone. On the other hand, among Comparative Examples 2 and 3, which use commercially available polyurethanes that do not contain the urea structural unit (Y), the decrease in transparency is suppressed in Comparative Example 2, but the low-temperature impact resistance is significantly reduced and the tensile elongation is also insufficient.Furthermore, in Comparative Example 3, although the low-temperature impact resistance is equivalent to that of Example 3, which was the lowest among Examples 1 to 3, the tensile modulus is lower than that of any of Examples 1 to 3.

Claims

1. A resin composition comprising a polyurethane containing a polyurethane structural unit (X) represented by the following formula (1) and a urea structural unit (Y) represented by the following formula (2), and a poly(meth)acrylate. 【Chemistry 1】 (In formula (1), x and m are integers of 1 or more. R in formulas (1) and (2) is an aliphatic group which may have a substituent and may contain a ring structure, or an aromatic group which may have a substituent. R' in formula (2) is an aliphatic group which may have a substituent and may contain a ring structure, or an aromatic group which may have a substituent. R and R' may be the same or different.)

2. The resin composition according to claim 1 , wherein the content of the polyurethane in the resin composition is 1% by mass or more and less than 30% by mass.

3. 2. The resin composition according to claim 1, wherein the polyurethane is produced from an aliphatic dihydroxy compound and a dicarbamate compound represented by the following formula (3): 【Chemistry 2】 (In the above formula (3), R １ represents an aliphatic group which may have a substituent or an aromatic group which may have a substituent, R ２ represents an aliphatic group consisting of only carbon and hydrogen atoms or an aromatic group consisting of only carbon and hydrogen atoms.

4. A molded article made from the resin composition according to any one of claims 1 to 3.

5. A transparent resin modifier comprising a polyurethane containing a polyurethane structural unit (X) represented by the following formula (1) and a urea structural unit (Y) represented by the following formula (2): 【Transformation 3】 (In formula (1), x and m are integers of 1 or more. R in formulas (1) and (2) is an aliphatic group which may have a substituent and may contain a ring structure, or an aromatic group which may have a substituent. R' in formula (2) is an aliphatic group which may have a substituent and may contain a ring structure, or an aromatic group which may have a substituent. R and R' may be the same or different.)

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