JP2019044161A - Polyurethane resin composition for cutting work - Google Patents

Abstract

To provide a polyurethane resin composition for cutting work solving a problem of appearance deterioration by "irregularity" of an urethane resin containing carbon black, excellent in cutting workability, high in heat resistance, and having excellent antistatic properties.SOLUTION: A polyurethane resin composition for cutting work (X) containing a cured article of polyol (A) having hydroxyl value of 200 to 2000 mgKOH/g and HLB value of 10.0 to 20.0, polyol (B) having HLB value of 4.0 or more and less than 10.0, and polyisocyanate (C), and carbon black (D) with a weight ratio of the polyol (A) and the polyol (B), (A)/(B) of 90/10 to 99.9/0.1.SELECTED DRAWING: None

Description

  The present invention relates to a polyurethane resin composition for machining. Specifically, the present invention relates to a polyurethane resin composition for cutting having excellent cutting workability and antistatic performance.

  In general, as a method for imparting antistatic properties to a resin such as polyolefin, a method of adding a surfactant or carbon black is known (for example, Patent Document 1).

On the other hand, as a polyol used in a polyurethane resin composition for cutting work, a polyol having a low molecular weight and high hydrophilicity is generally used in order to satisfy the cutting workability, but it is compatible with a hydrophobic isocyanate. However, when the resin surface after reaction hardening is observed, there is a problem that “unevenness” of fine resin is observed. In particular, when carbon black is added to develop antistatic performance, there is a problem that the “unevenness” of the resin becomes noticeable with carbon black and the appearance deteriorates.

Japanese Patent Laid-Open No. 7-18150

  The object of the present invention is to solve the problem of deterioration in appearance due to “unevenness” of the above-mentioned urethane resin containing carbon black, has high heat resistance, and has excellent antistatic properties and machinability. To provide things.

The inventors of the present invention have reached the present invention as a result of studies to achieve the above object.
That is, the present invention relates to a polyol (A) having a hydroxyl value of 200 to 2000 mgKOH / g and an HLB value of 10.0 to 20.0, and a polyol (B) having an HLB value of 4.0 to less than 10.0. , A polyurethane resin composition containing a cured product of polyisocyanate (C) and carbon black (D), wherein the weight ratio (A) / (B) of polyol (A) to polyol (B) is 90 / It is a polyurethane resin composition (X) for cutting which is 10-99.9 / 0.1.

  The polyurethane resin composition for cutting according to the present invention does not generate unevenness in the appearance of the urethane resin with carbon black added for antistatic, has excellent antistatic properties, and has excellent cutting workability due to low cutting resistance. It has the effect of having.

The polyurethane resin composition for cutting (X) of the present invention has a polyol (A) having a hydroxyl value of 200 to 2000 mgKOH / g and an HLB value of 10.0 or more and 20.0 or less, and an HLB value of 4.0 or more and 10 A polyurethane resin composition containing a cured product of less than 0.0 polyol (B) and polyisocyanate (C) and carbon black (D), wherein the weight ratio of polyol (A) to polyol (B) ( A polyurethane resin composition (X) for cutting, wherein A) / (B) is 90/10 to 99.9 / 0.1.

  The polyol (A) in the present invention is a polyol having two or more hydroxyl groups having a hydroxyl value of 200 to 2000 mgKOH / g and an HLB value of 10.0 or more and 20.0 or less, and a polyoxyalkylene polyol satisfying this condition ( A1), polyester polyol (A2), etc. are mentioned, and these may be used in combination.

Polyoxyalkylene polyol (A1)
Polyhydric alcohols such as ethylene glycol, glycerin and propylene glycol; amines such as triethanolamine, ethylenediamine and toluenediamine; polyhydric phenols such as bisphenol A and bisphenol F, and mixtures thereof, and alkylene oxide (hereinafter abbreviated as AO). It is a compound to which is added.
AO to be added preferably has 2 to 8 carbon atoms, and examples thereof include propylene oxide (hereinafter sometimes abbreviated as PO), ethylene oxide (hereinafter sometimes abbreviated as EO), butylene oxide, and the like. Two or more kinds may be used, but preferred are PO alone, EO alone, and a mixture of PO and EO. The additional form when two or more kinds are used in combination may be block or random.

Polyester polyol (A2)
Polyhydric alcohols [ethylene glycol, diethylene glycol, propylene glycol, 1,3- or 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and other dihydric alcohols; polyether polyol (particularly divalent) A mixture of these and a trihydric or higher polyhydric alcohol such as glycerin or trimethylolpropane] and a polycarboxylic acid such as adipic acid or sebacic acid, or an ester-forming derivative thereof [anhydrous A polyester polyol with a maleic acid, an acid anhydride such as phthalic anhydride, a lower alkyl (alkyl group having 1 to 4 carbon atoms) such as dimethyl terephthalate]; a condensation reaction product of the carboxylic acid anhydride and AO; AO (EO, PO) of these condensation reaction products ) Adduct; lactone (.epsilon. polylactone polyols obtained by the caprolactone) to ring-opening polymerization of a polyhydric alcohol as an initiator; polyhydric alcohol and a polycarbonate polyol obtained by reacting an alkylene carbonate.

The HLB value of the polyol (A) is 10.0 to 20.0.
A polyol having an HLB value of less than 10 has insufficient heat resistance, and a polyol having an HLB value of more than 20 is industrially difficult to obtain a polyurethane resin composition.
The HLB value is preferably 11.0 to 19.5, more preferably 12.0 to 19.1.
Moreover, when a polyol is 2 types or 3 types or more, an HLB value is an arithmetic mean value by the weight of the HLB value of each polyol.

The HLB value of the present invention is a value calculated by the Oda method [Co-authored by Oda and Terada, “Synthesis and application of surfactants” on page 501, published by Tsuji Shoten (1957)].

The hydroxyl value (unit: mgKOH / g) of the polyol (A) is 200 to 2,000. When the hydroxyl value is less than 200, the antistatic property of the molded product described later is insufficient, and when the hydroxyl value exceeds 2,000, it is difficult to obtain a polyurethane resin composition industrially.
The hydroxyl value is preferably 250 to 1,200, more preferably 300 to 900, and particularly preferably 350 to 800.
The hydroxyl value in the present invention is measured by a method specified in JIS K0070 (1995 edition). Moreover, when a polyol is 2 types or 3 types or more, a hydroxyl value is an arithmetic mean value by the weight of the hydroxyl value of each polyol.

  The polyol (B) in the present invention is a polyol having an HLB value of 4.0 or more and less than 10.0, and examples thereof include polyoxyalkylene polyol (B1) and polyester polyol (B2) that satisfy these conditions. You may use together.

Examples of the polyoxyalkylene polyol (B1) include those having the same composition as the above-mentioned polyoxyalkylene polyol (A1) but having different HLB values.

Examples of the polyester polyol (B2) include those having the same composition as the above-described polyester polyol (A2) and different HLB values. In addition, naturally occurring polyester polyols include those containing castor oil, castor oil derivatives, and mixtures thereof. Can be mentioned.

Castor oil refers to natural vegetable oil extracted from the seeds of Euphorbiaceae. However, it is preferably purified for industrial raw materials in order to reduce the inhibition of urethane reaction and the occurrence of side reactions. The castor oil derivative is a castor oil derivative obtained by reacting castor oil with another compound, and has a molecular weight of 1,000 to 1,500. Is preferred.
Castor oil derivatives include compounds obtained by adding AO to castor oil. AO preferably has 2 to 4 carbon atoms, and includes EO, PO and the like, and two or more kinds may be used.

The HLB value of the polyol (B) is 4.0 or more and less than 10.0.
Even if the HLB value is less than 4, even if the HLB value is 10 or more, it is difficult to obtain the effect of improving the appearance. The HLB value is preferably 4.0 to 9.0, and more preferably 4.4 to 8.0.

The weight ratio (A) / (B) of the polyol (A) to the polyol (B) is 90/10 to 99.9 / 0.1, preferably 93/7 to 99, from the viewpoint of the hardness of the molded product. 0.7 / 0.3, more preferably 95/5 to 99.5 / 0.5.

The polyisocyanate (C) in the present invention is not particularly limited as long as it is a compound having two or more isocyanate groups in the molecule.
Examples of (C) include aromatic polyisocyanate (C1), aliphatic polyisocyanate (C2), alicyclic polyisocyanate (C3), araliphatic polyisocyanate (C4), and modified products (C5) (for example, Urethane group, carbodiimide group, allophanate group, urea group, burette group, isocyanurate group, or oxazolidone group-containing modified product).
(C) may be used alone or in combination of two or more.

The aromatic polyisocyanate (C1) includes 6 to 16 aromatic diisocyanates, 6 to 20 aromatic triisocyanates, and carbon atoms (excluding carbon atoms in the NCO group; the carbon number of the following isocyanate is the same). A crude product of these isocyanates can be mentioned.
Specific examples include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4′- and / or 4, 4'-diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (crude MDI or polymeric MDI), and the like.

Examples of the aliphatic polyisocyanate (C2) include aliphatic diisocyanates having 6 to 10 carbon atoms.
Specific examples include 1,6-hexamethylene diisocyanate and lysine diisocyanate.

Examples of the alicyclic polyisocyanate (C3) include alicyclic diisocyanates having 6 to 16 carbon atoms.
Specific examples include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate, norbornane diisocyanate, and the like.

Examples of the araliphatic polyisocyanate (C4) include araliphatic diisocyanates having 8 to 12 carbon atoms.
Specific examples include xylylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate, and the like.

Examples of the modification of the modified polyisocyanate (C5) include urethane group, carbodiimide group, allophanate group, urea group, burette group, isocyanurate group, or oxazolidone group-containing modified product.
Specific examples include urethane-modified MDI and carbodiimide-modified MDI.

Among the above (C), it is preferable to use aromatic polyisocyanate (C1) and a modified product thereof from the viewpoint of solvent resistance.
The isocyanate group content in the polyisocyanate (C) is preferably 10 to 40% by weight.

  The polyurethane resin composition (X) for cutting according to the present invention is a polyurethane resin composition containing a cured product of the polyol (A), the polyol (B), and the polyisocyanate (C) and carbon black (D). is there.

As the carbon black (D) in the present invention, commercially available carbon black can be used, but from the viewpoint of antistatic performance, the surface area according to the BET ratio of the carbon black (D) is preferably 200 to 2000 m ² / g, more preferably from 700m ² / g~1600m ² / g.

  The amount of (D) used is polyol (A), polyol (B) and polyisocyanate (C) from the viewpoints of antistatic performance, from the viewpoint of reducing product contamination due to carbon loss, and from the viewpoint of balance of resin moldability. ) Is preferably 0.1 to 3.0% by weight, preferably 0.2 to 2.0% by weight, more preferably 0.3 to 1.0% by weight.

When the polyurethane resin composition (X) of the present invention is produced, the polyol component containing the polyol (A) and the polyol (B) and the polyisocyanate (C) polyisocyanate component are mixed and reacted. (D) is previously blended with the polyol component or the polyisocyanate component.

  The polyurethane resin composition (X) of the present invention includes, for example, the raw materials (A) to (D) described above, and, if necessary, an inorganic balloon (E) urethanization catalyst (F) and an additive (G) described later. Are put in a container, mixed, and cured by urethane reaction.

  The ratio of polyol (A), (B) and a mixture of polyol components containing other hydroxyl groups and the polyisocyanate (C) component was represented by an isocyanate index [(NCO group / OH group equivalent ratio) × 100]. In this case, the index can be varied, but is preferably 80 to 140, more preferably 85 to 120, particularly preferably 90 to 115.

  Further, as a reaction method of the polyol component such as (A) and (B) and the component (C), a part of the mixture of (A) and (B) and (C) may be used in advance even in the one-shot method. After reacting to form an NCO-terminated prepolymer, it is reacted with the remaining (A), or a mixture of (A) and (B) and a part of (C) are reacted in advance to obtain an OH-terminated prepolymer. After forming, the prepolymer method of reacting with the remaining (C) may be used.

The polyurethane resin composition for cutting (X) of the present invention can contain an inorganic balloon (E) for the purpose of lowering the linear expansion coefficient or lowering the density.
As the inorganic balloon (E) added for this purpose, various commercially available inorganic balloons can be used. For example, a glass microballoon is preferable.
The amount of the inorganic balloon (E) used is 1% by weight to 30% based on the total weight of the polyols (A) and (B) and the polyisocyanate (C) from the viewpoint of reducing the moldability and the linear expansion coefficient of the composition. % By weight is preferable, more preferably 2% by weight to 25% by weight, and particularly preferably 3% by weight to 20% by weight.

In order to obtain the polyurethane resin composition for cutting work (X) of the present invention, the urethanization catalyst (F) that can be used for curing reaction of the polyol component and the polyisocyanate component promotes the urethanization reaction. Usual urethanization catalysts can be used, and examples include triethylenediamine, bis (N, N-dimethylamino-2-ethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine, N, N— Tertiary amines such as PO adducts of dimethylaminopropylamine and carboxylic acid salts thereof, carboxylic acid metal salts such as potassium acetate, potassium octylate, stannous octoate, and organometallic compounds such as dibutyltin dilaurate.

Various additives (G) can be contained in the polyurethane resin composition (X) for cutting according to the present invention, if necessary, as long as the effects of the present invention are not impaired.
Additives (G) include dehydrating agents, lubricants, plasticizers, thixotropic agents, fillers, UV absorbers, anti-aging agents, antioxidants, colorants, flame retardants, antifungal agents, antibacterial agents, dispersions Agents (antisettling agents), antifoaming agents, foam stabilizers, and foaming agents.
The amount of the various (G) added is preferably 30% by weight or less, more preferably 20% by weight or less, based on the total weight of the polyols (A), (B) and the polyisocyanate (C).

<Polyurethane resin molded product (Y)>
The polyurethane resin molded product (Y) of the present invention is formed by molding a polyurethane resin composition for cutting (X).
The polyurethane resin molded product (Y) includes, for example, the constituent materials (A) to (D) described above, and, if necessary, the inorganic balloon (E) urethanization catalyst (F) and the additive (G). The mixture is put in a container, poured into a mold, and cured by a urethane reaction.
Further, if necessary, processing such as cutting, cutting, cutting, punching, and hot pressing may be performed.

The surface resistivity value of the polyurethane resin composition for cutting and the molded product of the present invention is preferably 1.0 × 10 ¹ from the viewpoint of reliability of components and antistatic formation when used for electronic components and the like. 1.0 × 10 ¹⁰ Ω / □, more preferably 1.0 × 10 ^{1 to} 1.0 × 10 ⁸ Ω / □, and particularly preferably 1.0 × 10 ^{1 to} 1.0 × 10 ⁶ Ω / □ is there.

  Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Hereinafter, unless otherwise specified, “%” represents “% by weight” and “parts” represents “parts by weight”.

Example 1
Sanix GP-250 (A-1) [Sanyo Chemical Industries, Ltd.] 2732.8 parts, Sanniks GP-3000 (B-1) [Sanyo Chemical Industries, Ltd.] 143.8 parts, Carbon ECP600JD (D-1) [made by Lion Specialty Chemicals] 79.4 parts, Glass Bubbles K37 (E-1) [made by 3M Co., Ltd.] 1587.3 parts, Neostan U-600 (F-1) [Tosoh Co., Ltd.] 0.288 parts, molecular sieve 3A-B powder (G-1) [Union Showa Co., Ltd.] 398.6 parts of each component were mixed in an 18 L pail, and this mixture was mixed with a commercially available vacuum stirrer. The mixture was put into a foaming machine and stirred and mixed for 30 minutes at 300 rpm under vacuum. Next, 5059.6 parts of Coronate MX (C-1) [manufactured by Tosoh Corporation] were added, and the mixture was stirred at 300 rpm for 15 minutes under vacuum.
The defoamed mixed solution is poured into a mold having a length of 450 mm × width of 450 mm × height of 100 mm, and is cured by heating at 100 ° C. for 10 hours in a curing furnace, whereby the polyurethane resin composition ( X-1) was obtained.

Examples 2-10, Comparative Examples 1-4
The same operations as in Example 1 were performed with the number of parts shown in Table 1, and the polyurethane resin compositions (X-2) to (X-10) of Examples 2 to 10 and the polyurethane resin compositions of Comparative Examples 1 to 4 were used. (X′-1) to (X′-4) were obtained.

The compounds described in Table 1 are as follows.

Polyol (A-1): Sanix GP-250, manufactured by Sanyo Chemical Industries, Ltd., average functional group number 3.0, number average molecular weight 250, hydroxyl value 673, HLB value 19.1 PO adduct of glycerin.
Polyol (A-2): Sanix GP-400, manufactured by Sanyo Chemical Industries, Ltd., average functional group number 3.0, number average molecular weight 420, hydroxyl value 400, HLB value 12.4 PO adduct of glycerin.
Polyol (A-3): Sanix SP-750, manufactured by Sanyo Chemical Industries, Ltd., average functional group number 6.0, number average molecular weight 750, hydroxyl value 450, HLB value 15.0, glycerin PO of sorbitol Adduct polyol (B-1): Sanix GP-3000, manufactured by Sanyo Chemical Industries, Ltd., average functional group number 3.0, number average molecular weight 3,000, hydroxyl value 56, HLB value 5.1, glycerin PO adduct polyol (B-2): Sannix GP-1000, manufactured by Sanyo Chemical Industries, Ltd., having an average functional group number of 3.0, a number average molecular weight of 1,000, a hydroxyl value of about 168, and an HLB value of 7.4. PO adduct polyol (B-3) of glycerin: castor oil SL, manufactured by Ito Oil Co., Ltd., average functional group number 2.7, number average molecular weight 950, hydroxyl value 160, HLB value 4.4]
Polyol (B′-1): oleyl alcohol, average functional group number 1.0, number average molecular weight 269, hydroxyl value 209, HLB value 2.8]
Polyol (B′-2): ethylene glycol, average functional group number 2.0, number average molecular weight 62, hydroxyl value 1810, HLB value 50.0]

Polyisocyanate (C-1): Coronate MX [carbodiimide-modified diphenylmethane diisocyanate. Tosoh Co., Ltd., isocyanate group content 28.7% by weight]
Polyisocyanate (C-2): VESTANAT IPDI [Isophorone diisocyanate, manufactured by EVONIC, isocyanate group content 37.6% by weight]

Carbon Black (D-1): Conductive carbon black powder “Carbon ECP600JD” having a BET specific surface area of 1400 m ² / g (manufactured by Lion Specialty Chemicals)
Carbon Black (D-2): Conductive carbon black powder “Carbon ECP” with a BET specific surface area of 800 m ² / g (manufactured by Lion Specialty Chemicals)

Inorganic balloon (E-1): Trade name “Glass Bubbles K37”, volume average particle size 45 μm, Urethane catalyst (F-1) manufactured by 3M Co., Ltd .: Neostan U-600 [manufactured by Nitto Kasei Co., Ltd.]
Dehydrating agent: (G-1): Molecular sieve 3A-B powder [Union Showa Co., Ltd.]

Polyurethane resin compositions (X-1) to (X-10) prepared in Examples 1 to 10 and polyurethane resin compositions (X′-1) to (X) for comparison prepared in Comparative Examples 1 to 4 About -4, (1) Density, (2) Appearance, (3) Thermal deformation temperature, (4) Surface specific resistance value, (5) Shore D hardness (6) Cutting resistance was measured by the following method.
The results are shown in Table 1.

(1) Density A 200 mm × 100 mm × 30 mm test piece is cut out from the center of a rectangular parallelepiped shaped product, and the weight of the test piece is weighed in a room temperature-controlled at 25 ° C. From the product of the lengths of the three sides. Divided by the calculated volume to obtain a density (g / cm ³ ).

(2) The appearance of the resin surface of the externally molded product was visually discriminated based on the following criteria to determine whether there was any unevenness of the mottled pattern.
○: No unevenness Δ: Slightly uneven ×: Unevenness

(3) Thermal deformation temperature The molded product was cut into a length of 80 mm x width 10 mm x thickness 4 mm to obtain a test piece, a load of 1.8 MPa was applied at a distance between fulcrums of 64 mm, and the thermal deformation temperature ( ° C).
Measurement was performed using a heat distortion tester [manufactured by Yasuda Seiki Seisakusho, model no. 148-HDPC-3] was used.

(4) Surface resistivity value After cutting the surface of the molded product by 1 mm to remove the skin layer on the surface and thoroughly removing the cutting powder remaining on the cutting surface, the surface resistance meter ST-4 (manufactured by Simco Japan) is used. The surface specific resistance value (Ω / □) of the cut surface was measured.

(5) Shore D hardness:
A rectangular parallelepiped shaped product was measured five times with a type D durometer in accordance with JIS K6253 to obtain an average value, which was defined as Shore D hardness.

(6) Cutting resistance (N) [Evaluation of cutting workability]
The molded product was cut into 80 mm × 30 mm × 10 mm, and used as a test piece for cutting resistance evaluation.
Cutting with an NC machine in a room temperature-controlled at 25 ° C. (Cutting blade: carbide slow-away tip, single blade, 16 mmφ, rotation speed: 5,000 rpm, feed rate: 3,000 mm / min, cutting depth: 4mm dynamometer [KISTLER Co., Ltd. "9272 type", amplifier: KISTLER Co., Ltd. "charge amplifier 5011 type", recorder: Graphtec It was measured by “WR7700” manufactured by Co., Ltd.
The smaller the numerical value of resistance (unit is N), the better the machinability.

The appearances of Examples 1 to 10 of the present invention are all good with no unevenness, and the heat distortion temperature, the surface specific resistance value, and the cutting resistance value are also good.
On the other hand, the polyurethane resin composition of the comparative example 1 which is a composition which does not use a polyol (B), the comparative example 2 whose HLB value of a polyol (B) is 10 or more, and the comparative example 3 whose HLB of a polyo (B) is less than 4. A mottled pattern of “unevenness” is observed on the surface of the surface, and the appearance is poor. In addition, the polyurethane resin composition of Comparative Example 4 having a polyol (A) / polyol (B) ratio of less than 90/10 has a good appearance, but the heat distortion temperature is greatly reduced and the heat resistance is poor, and the cutting resistance is low. Is too large to cut.

The molded article (Y) of the antistatic polyurethane resin composition (X) of the present invention is excellent in antistatic performance and cutting workability, and has a good appearance, so that it can be used widely and usefully as an electronic material component-related material.
Furthermore, since the coefficient of linear expansion is low and the dimensional change at high temperatures is small, it is particularly useful as a material for image forming apparatuses such as jigs for electronic parts, conveyance trays, and laser printers that require high temperature processing.

Claims (6)

Polyol (A) having a hydroxyl value of 200 to 2000 mgKOH / g and an HLB value of 10.0 to 20.0, a polyol (B) having an HLB value of 4.0 to less than 10.0, and a polyisocyanate (C) Polyurethane resin composition containing a cured product and carbon black (D), wherein the weight ratio (A) / (B) of the polyol (A) to the polyol (B) is 90/10 to 99.9 /. Polyurethane resin composition (X) for cutting which is 0.1. The polyurethane resin composition for cutting according to claim 1, wherein the polyol (B) is at least one selected from the group consisting of castor oil, an alkylene oxide adduct of castor oil, and an alkylene oxide adduct of glycerin.   The polyurethane resin composition for cutting according to claim 1 or 2, wherein the content of (D) is 0.1 wt% to 3 wt% based on the total weight of the (A) to (C). Cutting polyurethane resin composition according BET specific surface area is in any of claims 1 to 3 is 200~2,000m ² / g of the carbon black (D). The polyurethane resin composition for cutting according to any one of claims 1 to 4, further comprising an inorganic balloon (E). A polyurethane resin molded product (Y) obtained by molding the polyurethane resin composition according to claim 1.