TW201712070A - Polyurethane resin forming composition and polyurethane resin - Google Patents

Abstract

To provide a polyurethane resin forming composition which has excellent flame retardancy and workability and provides a resin case that is not susceptible to chemical stress cracking. The present invention relates to a polyurethane resin forming composition which is a polyurethane resin composition (X) containing a hydroxyl group-containing compound (A), an isocyanate group-containing compound (B) and a phosphorus-containing compound (C), and wherein the hydroxyl group-containing compound contains a castor oil-based polyol (A1) and the phosphorus-containing compound (C) contains a compound (C1) represented by general formula (1).

Description

Polyurethane resin forming composition and polyurethane resin

The present invention relates to a polyurethane resin-forming composition and a polyurethane resin.

Conventionally, in order to prevent contamination from the outside, the electronic circuit board or the electronic component is sealed using a polyurethane resin or the like. The present inventors have revealed that a polyurethane resin composition containing a specific polyurethane resin, a halogen-free phosphorus-based flame retardant, and a hydrolysis-resistant agent is excellent in flame retardancy and hydrolysis resistance, and is less problematic in terms of environment. (Patent Document 1).

On the other hand, a resin case is sometimes used for the peripheral parts of the sealing material. In this case, it is required that the frame or the outer casing of the electronic substrate is not subjected to chemical stress cracking, but the polyurethane resin composition disclosed so far has insufficient chemical stress cracking. . The chemical stress cracking is a typical brittle fracture generated under tensile stress below the tensile strength of the resin outer casing, and in the molded product, it is a portion where the chemical adhesion and contact tensile stress are generated (loaded In the case of a part or the like, a phenomenon of breakage (cracks, cracks) due to the multiplication of the chemical and the stress occurs with the passage of time. The chemical stress cracking property of the polyurethane resin composition of Patent Document 1 is not necessarily good. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2003-165903

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a polyurethane resin which is excellent in flame retardancy and workability and which is less likely to cause chemical stress cracking in a resin case. Sexual composition. [Means for solving the problem]

In order to solve the above problems, the inventors of the present invention have repeatedly tried hard to study, and found that a hydroxyl group-containing compound having a specific structure, an isocyanate group-containing compound, and a phosphorus-containing compound having a specific structure are used as a polyurethane resin-forming composition. The problem can be solved, and the present invention has been completed.

That is, the present invention relates to the invention disclosed below. (1) A polyurethane resin-forming composition comprising a hydroxyl group-containing compound (A), an isocyanate group-containing compound (B), and a phosphorus-containing compound (C)-containing polyurethane resin composition (X), the hydroxyl group-containing The compound contains a castor oil-based polyol (A1), and the phosphorus-containing compound (C) contains a compound (C1) represented by the following formula (1); (wherein R ₁ is a hydrocarbon group having an aromatic ring having 6 to 30 carbon atoms, R ₂ is the same or different aryl group having 6 to 15 carbon atoms, and n is 1 to 3) (2) as in (1) The polyurethane resin-forming composition, wherein the mass ratio of the hydroxyl group-containing compound (A) to the phosphorus-containing compound (C) is (A): (C) = 0.5 to 5.0: 1; (3) The polyurethane resin-forming composition according to (1) or (2) for use in an electric and electronic part; (4) a polyurethane resin which is formed into a composition of a polyurethane resin as described in (1) to (3) Obtained by hardening the object. [Effects of the Invention]

The polyurethane resin obtained by curing the polyurethane resin-forming composition of the present invention is excellent in flame retardancy and workability, and is less likely to cause chemical stress cracking in the resin case.

The polyurethane resin-forming composition of the present invention comprises a hydroxyl group-containing compound (A), an isocyanate group-containing compound (B), and a phosphorus-containing compound (C).

The hydroxyl group-containing compound used in the present invention contains a castor oil-based polyol (A1). It is excellent in workability by containing a castor oil-based polyol (A1).

As the castor oil-based polyol (A1), a polyhydric alcohol produced by using castor oil, castor oil fatty acid, and hydrogenated castor oil or hydrogenated castor oil fatty acid obtained by hydrogen addition can be used. The polyhydric alcohol is not particularly limited, and examples thereof include castor oil, a transesterified product of castor oil with other natural fats and oils, a reaction product of castor oil and a polyhydric alcohol, and an esterification reaction product of castor oil fatty acid and polyhydric alcohol. And a polyhydric alcohol obtained by addition polymerization of these alkylene oxides. These may be used alone or in combination of two or more.

The viscosity of the castor oil-based polyol (A1) at 25 ° C is preferably 800 mPa·s or less, more preferably 700 mPa·s or less. The average number of hydroxyl groups calculated from the amount added is preferably from 1.0 to 3.0, more preferably from 1.0 to 2.7. When it is such a range, the mixing viscosity at the time of producing a polyurethane resin-formable composition becomes suitable, and workability becomes favorable.

The blending amount of the castor oil-based polyol (A1) is preferably 20% by mass to 70% by mass, and more preferably 40% by mass to 60% by mass based on the urethane resin-forming composition. When the blending amount of the castor oil-based polyol (A1) is within the above range, compatibility and workability are preferable.

Further, in the polyol component used in the present invention, a polyol other than the castor oil-based polyol (A1) can be blended to the extent that the effects of the present invention are not impaired. The polyhydric alcohol is not particularly limited, and examples thereof include polyether polyols, polyester polyols, polybutadiene polyols, polycarbonate polyols, polyisoprene polyols, and polybutadiene. a hydride of a polyol and a hydride of a polyisoprene polyol. Among these, from the viewpoint of heat and humidity resistance, a polybutadiene polyol (A2) is preferred. These may be used alone or in combination of two or more.

The castor oil-based polyol (A1) may also be a hydroxyl-terminated urethane prepolymer obtained by reacting the isocyanate group-containing compound (B).

The isocyanate group-containing compound (B) to be used in the invention is not particularly limited as long as it is a compound having an isocyanate group in the molecule, and examples thereof include an aliphatic polyisocyanate compound, an alicyclic polyisocyanate compound, and an aromatic poly An isocyanate compound and an aromatic aliphatic polyisocyanate compound. These may be used alone or in combination of two or more.

The aliphatic polyisocyanate compound is not particularly limited, and examples thereof include tetramethylene diisocyanate, dodecamethylene diisocyanate, Hexamethylene diisocyanate (HDI), and 2,2,4-. Trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, diazonic acid diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methyl Pentane-1,5-diisocyanate, and the like.

The alicyclic polyisocyanate compound is not particularly limited, and examples thereof include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 1,4-cyclohexane. Diisocyanate, methylcyclohexyl diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, and the like.

The aromatic polyisocyanate compound is not particularly limited, and examples thereof include Tolylene Diisocyanate (TDI), 2,2'-diphenylmethane diisocyanate, and 2,4'-diphenylmethane. Diisocyanate, 4,4'-Diphenylmethane Diisocyanate (MDI), 4,4'-bibenzyldiisocyanate, 1,5-naphthyl diisocyanate, xylyl Diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and the like.

The aromatic aliphatic polyisocyanate compound is not particularly limited, and examples thereof include dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, and α,α,α,α-tetramethylxylene. Diisocyanate and the like.

As the polyisocyanate compound, an isocyanate group-terminated urethane prepolymer modified product, a carbodiimide modified product, or an isocyanate obtained by reacting an isocyanate group-containing compound and a hydroxyl group-containing compound may be used. A modified body such as a urethane modified body, an allophanate modified product, or a biuret modified body. These may be used alone or in combination of two or more.

As the polyisocyanate compound, MDI, TDI, HDI, and the above-described modified body are preferable from the viewpoint of reactivity, viscosity, and workability.

Phosphorus-containing compound (C) used in the present invention The phosphorus-containing compound (C) is a compound represented by the following formula (1). [Chemical 2]

In the formula (1), R ₁ is a hydrocarbon group having an aromatic ring having 6 to 30 carbon atoms, and from the viewpoint of flame retardancy, workability, and suppression of chemical stress cracking, it is preferably 6 to 25 carbon atoms. Preferably, the carbon number is 6 to 15, and more preferably an aromatic ring and/or a bisphenol structure.

In the formula (1), R ₂ is the same or different aryl group having 6 to 15 carbon atoms, and carbon number is preferably from 6 to 10 from the viewpoints of flame retardancy, workability, and suppression of chemical stress cracking. More preferably, it is a carbon number of 6-8, and further preferably a phenyl group and/or a xylyl group.

In the general formula (1), n is from 1 to 3, and from the viewpoint of workability, it is preferably from 1 to 2, more preferably 1.

As the phosphorus-containing compound (C), any other phosphorus-containing compound (C2) may be used in combination as long as it contains at least the compound (C1). By using (C1) and (C2) in combination, the flame retardancy is improved, and thus it is one of preferable forms. Although the reason for the improvement in flame retardancy is not clear, it is presumed that the reason is that the compatibility of (C2) and (C1) with other components in the polyurethane resin-forming composition is improved.

The other phosphorus-containing compound (C2) to be used in the present invention is not particularly limited as long as it is a phosphorus compound other than the compound (C1), and examples thereof include trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and phosphoric acid. Tricresyl ester, tri-xylylene phosphate, cresyl diphenyl phosphate, cresyl di 2,6-xylylene phosphate, tris(chloropropyl) phosphate, tris(tribromoneopentyl) phosphate Phosphate such as ester.

When the compound (C1) and the compound (C2) are used as the phosphorus-containing compound (C), the content of (C1) in (C) is preferably 15% by mass or more, more preferably 25% by mass or more, and still more preferably 35. More than % by mass. If it is these ranges, it is preferable from the viewpoint of flame retardancy, chemical stress cracking, and moist heat resistance.

The compounding amount of the phosphorus-containing compound (C) is preferably from 10% by mass to 60% by mass, and more preferably from 10% by mass to 30% by mass based on the urethane resin-forming composition. When the compounding amount of the phosphorus-containing compound (C) is within these ranges, it is preferable from the viewpoints of flame retardancy, workability, and suppression of chemical stress cracking.

The mass of the hydroxyl group-containing compound (A) and the phosphorus-containing compound (C) in the polyurethane resin-forming composition is preferably (A): (C) = 0.5 to 5.0: 1, more preferably 0.7 to 4.7:1, and more preferably 1.0 to 4.4:1. If it is these ranges, flame retardance, chemical stress cracking property, viscosity, and workability can coexist. Further, when the compound (C1) is not contained and the compound (C2) is contained as the compound (C), since it is not required to satisfy the compound (C) of the present application, it is not included in the above range.

The method for obtaining the polyurethane resin using the polyurethane resin-forming composition of the present invention is not particularly limited, and either one-shot method or two-liquid reaction can be used, but a two-liquid reaction is preferred. In the case of a two-liquid reaction, a curing agent containing a hydroxyl group-containing compound is mixed with a main component containing an isocyanate group-containing compound, and hardened, whereby a polyurethane resin is obtained. The phosphorus-containing compound and the ionic compound-trapping agent can be suitably used in any of the main component and the curing agent. In the case of mixing, it is not particularly limited as long as it is a mixing device which can be uniformly mixed.

In the polyurethane-forming composition of the present invention, the molar ratio (NCO/OH) of the isocyanate group to the hydroxyl group is preferably from 0.5 to 1.5, more preferably from 0.6 to 1.3. When the molar ratio of the isocyanate group to the hydroxyl group is outside this range, there is a case where hardening failure occurs.

In the polyurethane resin-forming composition of the present invention, it is preferred to carry out a plasticizer other than the phosphorus-containing compound, and more preferably, it does not contain a phthalate-containing or trimellitic acid. A plasticizer for esters. Here, the term "substantially not contained" means that the content of the plasticizer or the plasticizer containing phthalic acid ester or trimellitic acid ester in the polyurethane resin composition (X) is 0.01% by mass or less. The reason for this is that chemical stress cracking easily occurs in the resin case due to bleeding over time.

The polyurethane resin-forming composition of the present invention preferably contains substantially no water, trichloromonofluoromethane or dichlorodifluoromethane from the viewpoint of flame retardancy, workability, and suppression of chemical stress cracking. , monochlorodifluoromethane, dichlorotetrafluoroethane, trichlorotrifluoroethane, dichloromethane, trichloroethane, 1,1-dichloro-1-fluoroethane (HCFC-141b), chlorine Fluoromethane (HCFC-22), 1,2,2,2-tetrafluoroethane (HFC-134a), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1 , 3,3-pentafluorobutane (HFC-365mfc), n-pentane, cyclopentane and hexane and other foaming agents. Here, the term "substantially not contained" means 0.3% by mass or less in the polyurethane resin-forming composition.

Further, various additives such as a catalyst, an antioxidant, a moisture absorbent, an antifungal agent, and a decane coupling agent may be added to the polyurethane resin-forming composition of the present invention. Examples of the decane coupling agent include alkoxy decanes, vinyl group-containing decane coupling agents, epoxy group-containing decane coupling agents, methacryl group-containing decane coupling agents, and acrylic group-containing decane coupling agents. .

The mixed viscosity of the polyurethane resin-forming composition of the present invention is preferably 3,000 or less (mPa·s), more preferably 2,500 or less (mPa·s). Further, the mixed viscosity was measured by the method described in the examples.

The flame retardancy of the polyurethane resin obtained by curing the polyurethane resin-forming composition of the present invention is preferably in a UL94 standard, and preferably has a V-1 level flame retardancy, and more preferably has a V-0 level flame retardancy. .

The chemical stress cracking property of the polyurethane resin obtained by curing the polyurethane resin-forming composition of the present invention is preferably 0.5% or more, more preferably 0.7%, in the critical strain after 25 ° C × 60% RH × 48 hours. the above. If it is such a range, it is good from the viewpoint of not forming a crack in the frame and outer casing of a board|substrate. [Examples]

Hereinafter, the polyurethane resin-forming composition of the present invention will be described in detail based on examples and comparative examples. In addition, "parts" and "%" in this specification mean "mass part" and "mass %", respectively, except the case where it is specifically indicated.

The raw materials used in the examples and comparative examples are shown below. (castor oil-based polyol (A1)) A1-1: castor oil (trade name: castor oil Marutoku A, manufactured by Ito Oil Co., Ltd.) A1-2: castor oil fatty acid-polyol ester (trade name) :URIC Y-403, manufactured by Ito Oil Co., Ltd.) (Polybutadiene polyol (A2)) A2-1: Polybutadiene polyol having an average hydroxyl value of 46.6 mgKOH/g (trade name: Poly bd R-45HT , manufactured by Idemitsu Kosan Co., Ltd. (Isocyanate-containing compound (B)) B1: Polymerized MDI (trade name: Foamlite 500B, manufactured by BASF INOAC Polyurethanes) B2: Carbon Diterpenoid modified MDI (trade name: Lupranate MM-103, manufactured by BASF Innocent Polyurethane Co., Ltd.) B3: TDI (trade name: Coronate T-80, Tosoh Corporation B4: Isocyanurate modified HDI (trade name: Durane TLA-100, manufactured by Asahi Kasei Chemicals) (phosphorus compound (C)) C1-1: bisphenol A bis(diphenyl phosphate) Product Name: Adekastab FP600, manufactured by ADEKA) C1-2: 1,3-phenylene bis(2,6-dimethylphenyl=phosphate) (trade name) : PX-200, manufactured by Daiba Chemical Industry Co., Ltd.) C1-3: Resorcinol bis(diphenyl phosphate) (trade name: Adekastab PFR, manufactured by Adico) C1- 4: bisphenol A bis(diphenyl phosphate) (trade name: CR-741, manufactured by Daiba Chemical Industry Co., Ltd.) C2-1: cresyl phosphate 2,6-xylene ester (trade name: PX- 110, manufactured by Daiba Chemical Industry Co., Ltd.) C2-2: Tri-xylylene phosphate (trade name: TXP, manufactured by Daiba Chemical Industry Co., Ltd.)

<Examples 1 to 12 and Comparative Examples 1 to 2> The main component and the curing agent of the polyurethane resin-forming composition of each of the examples and the comparative examples were prepared by the formulation shown in Table 1. At 25 ° C, a mixing machine (trade name: defoaming Ryotaro, manufactured by Thinky Co., Ltd.) was used, and the mixing ratio was 100/70 (weight ratio: NCO/OH = 0.8) at 2000 rpm and the total amount was changed. The prepared hardener and the main agent were mixed in an amount of 100 g for 1 minute, whereby the polyurethane resin-forming composition of each example was obtained.

[Table 1] Unit: parts by mass

<Evaluation Method> (Mixed Viscosity) The obtained polyurethane resin-forming composition was adjusted to 25 ° C, and the viscosity after 3 minutes from the start of mixing was measured by a BM-type viscometer.

(Flame Retardancy) The flame retardancy was measured according to UL94 (flame retardance of a plastic material) of UL specifications, and was evaluated as follows. ○: In the UL94 specification, V-1 or V-0 ×: in the UL94 specification, V-2

(Evaluation of chemical stress cracking) Acrylonitrile Butadiene Styrene (ABS) test piece (trade name: Kobe Polysheet ABS, manufactured by Shinsei Electric Co., Ltd.) was mounted on a long axis of 100 mm and a short axis. The resin sheet of the example was attached to the surface of the test piece of 40 mm on the 1/4 elliptical holder shown in Fig. 1, and then left in an environment of 25 ° C × 60% RH for 48 hours to measure cracking. Position X, and use Equation 1 to find the critical strain value. Based on the critical strain value, the chemical stress crackability was graded as follows. [Expression 1] ε: critical strain value a: long axis of the ellipse 100 mm b: short axis of the ellipse 40 mm X: distance from the fixed end of the test piece to the crack generating point of the test piece mm t: test piece thickness 2.0 mm <evaluation> ○ (sufficiently practical): the critical strain value (ε) is 0.7% or more × (not practical): the critical strain value (ε) is less than 0.7%

<Evaluation Result> As can be seen from the examples 1 to 12, the mixed viscosity of the polyurethane resin-forming composition of the present invention is in a usable range, and it is understood that the flame retardancy and the workability are excellent, and the resin shell is used. It is difficult to generate chemical stress cracks.

On the other hand, when the phosphorus-containing compound (C) does not contain the compound (C1) represented by the above formula (1) as in Comparative Example 1, chemical stress cracking easily occurs. In the system containing no castor oil-based polyol (A1) as in Comparative Example 2, the mixed viscosity was high and the workability was poor, and the flame retardancy was also poor. [Industrial availability]

The polyurethane resin obtained by curing the polyurethane resin-forming composition of the present invention can be suitably used for electric and electronic parts. Examples of such an electric and electronic component include a transformer or a machine control substrate such as a transformer coil, a choke coil, and a reactor coil. The electric and electronic parts using the polyurethane resin of the present invention can be used for an electric washing machine, a toilet seat, a water heater, a water purifier, a bath, a dishwasher, a solar panel, a power tool, a car, a motorcycle, and the like. In addition, when the polyurethane resin-forming composition of the present invention is used, the polyurethane resin obtained by curing is less likely to cause chemical stress cracking in the resin case, and therefore it can be suitably used in the field of electrical and electronic parts using a resin outer casing.

A‧‧‧ ellipse long axis
B‧‧‧ elliptical short axis
X‧‧‧ crack origin
t‧‧‧Test piece thickness

Figure 1 is a cross-sectional view of a 1/4 elliptical clamp for chemical stress cracking evaluation.

A‧‧‧ ellipse long axis

B‧‧‧ elliptical short axis

X‧‧‧ crack origin

t‧‧‧Test piece thickness

Claims (4)

A polyurethane resin-forming composition comprising a hydroxyl group-containing compound (A), an isocyanate group-containing compound (B), and a phosphorus-containing compound (C)-containing polyurethane resin composition (X), wherein the hydroxyl group-containing compound contains The castor oil is a polyol (A1), and the phosphorus-containing compound (C) contains the compound (C1) represented by the following formula (1). In the formula, R ₁ is a hydrocarbon group having an aromatic ring having 6 to 30 carbon atoms, and R ₂ is the same or different aryl group having 6 to 15 carbon atoms, and n is 1 to 3. The polyurethane resin-forming composition according to claim 1, wherein the mass ratio of the hydroxyl group-containing compound (A) to the phosphorus-containing compound (C) is (A): (C) = 0.5 - 5.0:1. The polyurethane resin-forming composition according to claim 1 or 2, which is used for an electric and electronic part. A polyurethane resin obtained by curing a polyurethane resin-forming composition according to any one of claims 1 to 3.