JP2019011393A - Urethane resin composition, urethan resin molded article using the same - Google Patents

Abstract

To provide an urethane resin composition excellent in workability and having long usable life, and an urethane resin molded article small in permanent compression factor and tensile permanent elongation, and excellent in abrasion resistance.SOLUTION: A urethane resin composition containing a main agent (i) containing an urethane prepolymer having an isocyanate group at a terminal (A), and a curing agent (ii) having 1,3-bishydroxyethoxy benzene, in which the urethane prepolymer (A) is a reaction product between polyol (a1) and polyisocyanate containing paraphenylene diisocyanate (a2).SELECTED DRAWING: None

Description

  The present invention relates to a urethane resin composition and a urethane resin molded product using the same.

  Molded articles obtained using a urethane resin composition are currently used in various applications such as automobile parts, home appliance parts, packaging materials, leather-like sheets, industrial rolls and the like.

  The molded product is required to have various characteristics corresponding to its use. For example, when the molded product is used as an industrial roll, the development of a urethane resin molded product having excellent wear resistance and durability is required to enable use under high-speed operation and high-load operation. I came.

  As the urethane resin molded article having excellent abrasion resistance and durability, (a) a prepolymer having an isocyanate group at a terminal obtained by reacting paraphenylene diisocyanate with a compound containing two or more active hydrogen groups; (B) a heat comprising a curing agent of 1,4-bis (2-hydroxyethoxy) benzene and trimethylolpropane, or 1,4-bis (2-hydroxyethoxy) benzene and a polyol containing an isocyanurate ring. A curable urethane elastomer (for example, see Patent Document 1) is disclosed.

  However, although the thermosetting urethane elastomer has a small distortion at the time of compressive deformation and elongation deformation, 1,4-bis (2-hydroxyethoxy) benzene used as a raw material has a high freezing point and rapidly crystallizes at 90 ° C. or less. Therefore, there is a problem that workability is remarkably inferior.

  Therefore, there has been a demand for a urethane resin composition that is excellent in workability, has small compression set and tensile permanent elongation of the obtained urethane resin molded article, and is excellent in wear resistance.

JP-A-1-126318

  The problem to be solved by the present invention is to provide a urethane resin composition having excellent workability, and a urethane resin molded article having a small compression set and tensile permanent elongation obtained by using the urethane resin composition and having excellent wear resistance. It is to be.

  As a result of diligent research to solve the above problems, the present inventor has obtained a urethane resin containing an isocyanate group-terminated urethane prepolymer which is a reaction product of a polyisocyanate containing polyphenylene diisocyanate and a polyol, and a specific curing agent. The inventors have found that the above problems can be solved by using the composition, and have completed the present invention.

  That is, the present invention provides a urethane resin composition comprising a main agent (i) containing a urethane prepolymer (A) having an isocyanate group at a terminal and a curing agent (ii) containing 1,3-bishydroxyethoxybenzene. The urethane prepolymer (A) is a reaction product of a polyol (a1) and a polyisocyanate (a2) containing paraphenylene diisocyanate, and uses the urethane resin composition The present invention relates to a molded urethane resin product.

  The urethane resin composition of the present invention has excellent workability, has a small compression set and tensile permanent elongation, and can form a urethane resin molded product having excellent wear resistance. For example, an industrial roll or a paper roll , Belts, wire saw rolls, packings, solid tires, casters, anti-vibration materials, and the like that are required to have wear resistance and durability.

  The urethane resin composition of the present invention comprises a main agent (i) containing a urethane prepolymer (A) having an isocyanate group at the terminal and a curing agent (ii) containing 1,3-bishydroxyethoxybenzene. It is characterized by that.

  As said main ingredient (i), the urethane prepolymer (A) which has an isocyanate group at the terminal is used. The “main agent” in the present invention refers to a composition exceeding 50% by mass with respect to the total amount of the composition.

  As the urethane prepolymer (A), a reaction product of a polyol (a1) and a polyisocyanate (a2) containing paraphenylene diisocyanate is used.

  Examples of the polyol (a1) include polyester polyol, polyether polyol, polycarbonate polyol, polybutadiene polyol, and polyacryl polyol. Among these, it is possible to obtain a urethane resin composition having excellent workability, and since a urethane resin molded article having a small compression set and tensile permanent elongation and excellent wear resistance can be formed, polyester polyol or Polyether polyols or polycarbonate polyols are preferred. These polyols (a1) can be used alone or in combination of two or more.

  Examples of the polyester polyol include a polyester polyol obtained by reacting a low molecular weight polyol and a polycarboxylic acid; a polyester polyol obtained by a ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone; Examples include polyester polyols obtained by polymerization. These polyester polyols can be used alone or in combination of two or more.

  Examples of the low molecular weight polyol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, 1,3-butanediol and the like having a molecular weight of about 50 to 300. Aliphatic polyols such as cyclohexane dimethanol, and polyols having an aromatic structure such as bisphenol A and bisphenol F.

  Examples of the polycarboxylic acid that can be used for the production of the polyester polyol include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid; terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid. And aromatic polycarboxylic acids such as anhydrides or esterified products thereof.

  Examples of the polyether polyol include polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran. Moreover, what carried out addition polymerization of the alkylene oxide by using the 1 type (s) or 2 or more types of the compound which has 2 or more of active hydrogen atoms as an initiator is mentioned. Examples of the compound having two or more active hydrogen atoms include propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, diester, and the like. Examples include glycerin, trimethylolethane, trimethylolpropane, water, hexanetriol and the like. Examples of the alkylene oxide include propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran. These polyether polyols can be used alone or in combination of two or more.

  The polycarbonate polyol is obtained by an esterification reaction of carbonic acid and a carbonate ester with a polyhydric alcohol. Examples of the polyhydric alcohol include 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. These polycarbonate polyols can be used alone or in combination of two or more.

  As the polyisocyanate (a2), it is possible to obtain a urethane resin composition having excellent workability, and to form a urethane resin molded article having a small compression set and tensile permanent elongation and excellent wear resistance. Therefore, paraphenylene diisocyanate is used as an essential component.

  Moreover, as said polyisocyanate (a2), another polyisocyanate can be combined and used as needed.

  Examples of the other polyisocyanates include polyisocyanates having an aliphatic cyclic structure such as cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate; 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane. Aromatic polyisocyanates such as diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate; and aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate.

  The reaction between the polyol (A) and the polyisocyanate (B) is, for example, when the isocyanate group equivalent of the polyisocyanate (B) is represented by [NCO] and the hydroxyl equivalent of the polyol is represented by [OH]. The equivalent ratio ([NCO] / [OH]) between the polyisocyanate (B) and the polyol (A) is preferably in the range of 0.5 to 2.5, preferably in the range of 0.7 to 1.1. It is more preferable to carry out with.

  As the curing agent (ii), 1,3-bishydroxyethoxybenzene is essential.

  Moreover, as said hardening | curing agent (ii), another hardening | curing agent can be combined and used as needed.

  Examples of the other curing agent include ethylene glycol, 1,4-butanediol, trimethylolpropane, 1,4-bishydroxyethoxybenzene, and the like.

  As a urethane resin molding of this invention, what heat-molded the said urethane resin composition is mentioned, for example.

  Examples of the heat molding method include a method of injecting the uniformly mixed urethane resin composition into a sheet-like mold or a cylindrical mold and thermosetting.

  As the thermosetting, it is preferable to perform primary curing at 100 to 150 ° C. for 1 to 4 hours, and then perform secondary curing at 90 to 130 ° C. for 10 to 20 hours.

  After the thermosetting, it is preferable that the urethane reaction of the urethane resin composition is completed.

  The urethane resin molded product of the present invention can be suitably used for applications requiring wear resistance and durability, such as industrial rolls, papermaking rolls, belts, wire saw rolls, packings, solid tires, casters, and anti-seismic materials. .

(Synthesis Example 1: Synthesis of urethane prepolymer (1))
In a four-necked flask equipped with a thermometer, a stirrer, and an inert gas inlet, 24 parts by mass of paraphenylene diisocyanate, 70 parts by mass of polyester polyol (“Polylite CMA-1024” manufactured by DIC Corporation) and polyester polyol (manufactured by DIC Corporation) 30 parts by weight of “Polylite OD-X-2380”) was charged and reacted at 80 ° C. for 4 hours to obtain a urethane prepolymer (1).

(Synthesis Example 2: Synthesis of urethane prepolymer (2))
A four-necked flask equipped with a thermometer, a stirrer, and an inert gas inlet was charged with 26 parts by mass of paraphenylene diisocyanate and 100 parts by mass of a polyester polyol (“Polylite OD-X-2518” manufactured by DIC Corporation) at 80 ° C. It was made to react for 4 hours and the urethane prepolymer (2) was obtained.

(Synthesis Example 3: Synthesis of urethane prepolymer (3))
A four-necked flask equipped with a thermometer, a stirrer, and an inert gas inlet is charged with 26 parts by mass of paraphenylene diisocyanate and 100 parts by mass of polytetramethylene glycol ("PTMG1000" manufactured by Mitsubishi Chemical Corporation), and is heated at 80 ° C for 4 hours. Reaction was performed to obtain a urethane prepolymer (3).

(Example 1: Production of urethane resin molded product (1))
The urethane prepolymer (1) obtained in Synthesis Example 1 adjusted to a temperature of 80 ° C. and 1,3-bishydroxyethoxybenzene (hereinafter abbreviated as “DER”) at 100 ° C. NCO / OH = 1.05 After mixing and stirring at a mixing ratio of (molar ratio) and then degassing under reduced pressure for 1 minute, the mixture was poured into a sheet mold having a length of 200 mm × width of 200 mm × thickness of 2 mm and a cylindrical mold having a diameter of 400 mm × thickness of 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to produce sheet-like and columnar urethane resin moldings (1).

(Example 2: Production of urethane resin molding (2))
The urethane prepolymer (2) obtained in Synthesis Example 2 adjusted to 80 ° C. and DER at 100 ° C. were mixed and stirred at a blending ratio of NCO / OH = 1.05 (molar ratio), and then depressurized for 1 minute. After foaming, it was poured into a sheet mold having a length of 200 mm × width of 200 mm × thickness of 2 mm and a cylindrical mold having a diameter of 400 mm × thickness of 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to prepare sheet-like and columnar urethane resin molded products (2).

(Example 3: Production of urethane resin molded product (3))
The urethane prepolymer (3) obtained in Synthesis Example 3 adjusted to a temperature of 80 ° C. and DER at 100 ° C. were mixed and stirred at a blending ratio of NCO / OH = 1.05 (molar ratio), and then depressurized for 1 minute. After foaming, it was poured into a sheet mold having a length of 200 mm × width of 200 mm × thickness of 2 mm and a cylindrical mold having a diameter of 400 mm × thickness of 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to produce sheet-like and columnar urethane resin molded products (3).

(Example 4: Production of urethane resin molded product (4))
A mixture of DER / BHEB = 4/6 (weight ratio) of DER and BHEB obtained in Synthesis Example 3 adjusted to 80 ° C. and NCO / OH = 1.05 (molar ratio). Then, after degassing under reduced pressure for 1 minute, the mixture was poured into a sheet mold having a length of 200 mm × width 200 mm × thickness 2 mm and a cylindrical mold having a diameter 400 mm × thickness 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to produce sheet-like and columnar urethane resin molded articles (4).

(Comparative Example 1: Production of urethane resin molded product (C1))
The urethane prepolymer (1) obtained in Synthesis Example 1 adjusted to a temperature of 80 ° C. and 1,4-butanediol (hereinafter abbreviated as “1,4-BG”) at 40 ° C. are NCO / OH = 1. The mixture was mixed and stirred at a mixing ratio of 0.05 (molar ratio), then degassed under reduced pressure for 1 minute, and then poured into a sheet mold having a length of 200 mm × width 200 mm × thickness 2 mm and a cylindrical mold having a diameter 400 mm × thickness 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to produce sheet-like and columnar urethane resin moldings (C1).

(Comparative Example 2: Production of urethane resin molded product (C2))
The urethane prepolymer (1) obtained in Synthesis Example 1 adjusted to a temperature of 100 ° C. and 1,4-bishydroxyethoxybenzene (hereinafter abbreviated as “BHEB”) at 120 ° C. NCO / OH = 1.05 After mixing and stirring at a mixing ratio of (molar ratio) and then degassing under reduced pressure for 1 minute, the mixture was poured into a sheet mold having a length of 200 mm, a width of 200 mm, and a thickness of 2 mm and a cylindrical mold having a diameter of 400 mm and a thickness of 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to produce sheet-like and columnar urethane resin moldings (C2).

(Comparative Example 3: Production of urethane resin molded product (C3))
The urethane prepolymer (2) obtained in Synthesis Example 2 adjusted to 80 ° C. and 1,4-BG at 40 ° C. were mixed and stirred at a blending ratio of NCO / OH = 1.05 (molar ratio), then 1 After degassing for 10 minutes under reduced pressure, the mixture was poured into a sheet mold having a length of 200 mm, a width of 200 mm, and a thickness of 2 mm and a cylindrical mold having a diameter of 400 mm and a thickness of 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to produce sheet-like and columnar urethane resin moldings (C3).

(Comparative Example 4: Production of urethane resin molded product (C4))
The urethane prepolymer (2) obtained in Synthesis Example 2 adjusted to 100 ° C. and 120 ° C. BHEB were mixed and stirred at a blending ratio of NCO / OH = 1.05 (molar ratio), and then degassed under reduced pressure for 1 minute. After that, it was poured into a sheet mold having a length of 200 mm, a width of 200 mm, and a thickness of 2 mm and a cylindrical mold having a diameter of 400 mm and a thickness of 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to produce sheet-like and columnar urethane resin molded articles (C4).

(Comparative Example 5: Production of urethane resin molded product (C5))
The urethane prepolymer (3) obtained in Synthesis Example 3 adjusted to 80 ° C. and 1,4-BG at 40 ° C. were mixed and stirred at a blending ratio of NCO / OH = 1.05 (molar ratio), then 1 After degassing for 10 minutes under reduced pressure, the mixture was poured into a sheet mold having a length of 200 mm, a width of 200 mm, and a thickness of 2 mm and a cylindrical mold having a diameter of 400 mm and a thickness of 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to produce sheet-like and columnar urethane resin moldings (C5).

(Comparative Example 6: Production of urethane resin molded product (C6))
The urethane prepolymer (3) obtained in Synthesis Example 3 adjusted to 100 ° C. and 120 ° C. BHEB were mixed and stirred at a blending ratio of NCO / OH = 1.05 (molar ratio), and then degassed under reduced pressure for 1 minute. After that, it was poured into a sheet mold having a length of 200 mm, a width of 200 mm, and a thickness of 2 mm and a cylindrical mold having a diameter of 400 mm and a thickness of 120 mm. These molds were primarily cured at 110 ° C. for 2 hours, and then secondarily cured at 110 ° C. for 17 hours to produce sheet-like and columnar urethane resin molded articles (C6).

  The following evaluation was performed using the urethane prepolymers obtained in the above synthesis examples and the urethane resin molded products obtained in the examples and comparative examples.

[Method of evaluating workability]
400 g of prepolymer was weighed in a 500 g can and sealed with nitrogen, and stored at a predetermined working temperature. After storage, the time when the change rate of isocyanate group equivalent exceeded 3% was measured and evaluated as follows.
◎: 24 hours or more ○: 16 hours or more and less than 24 hours Δ: 8 hours or more and less than 16 hours ×: Less than 8 hours

[Measurement method of compression set]
Compression permanent distortion was measured for the cylindrical urethane resin moldings obtained in Examples and Comparative Examples in accordance with JIS-K-7312 (1996) under the conditions of a compression rate of 25% and 70 ° C. × 22 hours. The evaluation was as follows.
◎: Less than 20% ○: 20% or more and less than 25% Δ: 25% or more and less than 30% ×: 30% or more

[Measurement method of tensile permanent elongation]
The test piece similar to the tensile strength test of JIS-K-7312 (1996) was used for the sheet-like urethane resin molding obtained by the Example and the comparative example, and it was 10 minutes in the state extended | stretched between the marked lines 100%. The change rate of the distance between the marked lines after the tension was released was measured and evaluated as follows.
A: Less than 20% B: 20% or more and less than 40% X: 40% or more

[Abrasion resistance evaluation method]
In accordance with the Taber abrasion test of JIS-K-7312 (1996), the sheet-like urethane resin moldings obtained in the examples and comparative examples were loaded with 1 kg and 1000 revolutions with a Taber abrasion test device (manufactured by Toyo Seiki Seisakusho " Abrasion weight loss (mg) was measured with a rotary abrasion tester ") and evaluated as follows.
A: Less than 40 mg B: 40 mg or more and less than 60 mg x: 60 mg or more

  Compositions of urethane resin molded products (1) to (4) produced in Examples 1 to 4 and evaluation results, and compositions of urethane resin molded products (C1) to (C6) produced in Comparative Examples 1 to 6, and The evaluation results are shown in Table 1.

  From the evaluation results shown in Table 1, it was confirmed that the urethane resin composition of the present invention was excellent in workability of the urethane prepolymer. Moreover, it has confirmed that the urethane resin molding formed using the urethane resin composition of this invention has a small compression set and tensile permanent elongation, and is excellent in abrasion resistance.

  On the other hand, although Comparative Examples 1-6 is an example which does not use DER as a hardening | curing agent, it has confirmed that tensile permanent elongation and abrasion resistance were inadequate.

Claims (2)

A urethane resin composition comprising a main agent (i) containing a urethane prepolymer (A) having an isocyanate group at the terminal, and a curing agent (ii) containing 1,3-bishydroxyethoxybenzene,
The urethane resin composition, wherein the urethane prepolymer (A) is a reaction product of a polyol (a1) and a polyisocyanate (a2) containing paraphenylene diisocyanate.   A urethane resin molded product, which is a cured molded product of the urethane resin composition according to claim 1.