JP5112680B2 - Polyurethane resin composition - Google Patents

Description

  The present invention relates to a polyurethane resin composition.

  Generally, polyurethane-based resins are used as waterproof gloves. However, gloves made of polyurethane resin are difficult to increase in film thickness and have problems of poor alcohol resistance. Moreover, although this glove can be used for the handling of IC chips for information electronics related technology (IT), in that case, it is necessary not to include a metal component or the like, that is, to be metal-free.

The polyurethane-based resin is generally a solvent-based resin. However, in recent years, from the viewpoint of the environment and the like, conversion from a solvent system to an aqueous system has been performed, and an aqueous water-dispersed polyurethane resin has been studied as a polyurethane resin.
In order to solve these problems, a resin composition (see Patent Documents 1 and 2) having an aqueous polyurethane resin and a polyolefin resin is known.

JP 2001-011254 A JP 11-14149 A

  However, in any of the above resin compositions, those that can be formed into a thick film often have low resistance to solvents such as alcohol and acetone, while those that have high solvent resistance are Cracks tend to occur and it may be difficult to satisfy both.

  Therefore, an object of the present invention is to obtain a water-dispersed polyurethane resin in which both thick film formability and solvent resistance are sufficiently improved.

  This invention has a polyurethane-vinyl polymer composite resin (A1) comprising a polyurethane component (u1) having a structural unit derived from an aromatic isocyanate and a vinyl polymer component (v), and a structural unit derived from an aliphatic isocyanate. Polyurethane-vinyl comprising the mixed resin with the urethane resin (B2) comprising the polyurethane component (u2), the polyurethane-vinyl polymer composite resin (A1), the polyurethane component (u2) and the vinyl polymer component (v). A resin composition containing a mixed resin of a polymer composite resin (A2) or a mixed resin of the polyurethane-vinyl polymer composite resin (A2) and a urethane resin (B1) comprising the polyurethane component (u1). The total polyurethane content, which is all the polyurethane components in the resin composition, is a polyvalent isocyanate. Having a skeleton derived from the polyol and the polyol, wherein at least a part of the total polyurethane content has a skeleton derived from the carboxyl group-containing polyol, the skeleton derived from the aromatic polyvalent isocyanate, and the aliphatic polyvalent By using a polyurethane-based resin composition having a molar ratio of 90/10 to 10/90 with respect to the skeleton derived from isocyanate, the above problem has been solved.

  This invention is a mixed resin of a specific polyurethane-vinyl polymer composite resin (A1) and a urethane resin (B2), a specific polyurethane-vinyl polymer composite resin (A1), a polyurethane-vinyl polymer composite resin ( Since a resin composition containing a mixed resin of A2) or a specific polyurethane-vinyl polymer composite resin (A2) and a urethane resin (B1) is used, the resulting water-dispersed polyurethane resin The composition has sufficient thick film moldability and solvent resistance.

The present invention will be described in detail below.
The polyurethane resin composition according to the present invention is a mixed resin of a polyurethane-vinyl polymer composite resin comprising a polyurethane component and a vinyl polymer component and a urethane resin comprising a polyurethane component, or the polyurethane-vinyl polymer composite. It is a resin composition containing a mixed resin of a resin and a different polyurethane-vinyl polymer composite resin.

[Polyurethane component, polyurethane resin]
The polyurethane component refers to a specific polyurethane having a polyisocyanate and a structure derived from a polyol as a repeating unit.

  Examples of the polyurethane component include a polyurethane component having a structural unit derived from an aromatic isocyanate (hereinafter referred to as “polyurethane component (u1)”) and a polyurethane component having a structural unit derived from an aliphatic isocyanate (hereinafter referred to as “polyurethane component”). (U2) "). Hereinafter, the urethane resin composed of the polyurethane component (u1) is referred to as “urethane resin (B1)”, and the urethane resin composed of the polyurethane component (u2) is referred to as “urethane resin (B2)”.

[Aromatic isocyanate constituting polyurethane component (u1)]
Examples of the aromatic isocyanate constituting the polyurethane component (u1) include aromatic organic polyvalent isocyanate. Specific examples thereof include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, and the like. Can do. Among these, 2,4-tolylene diisocyanate, 2,4′-diphenylmethane diisocyanate and the like are preferable.

[Aliphatic isocyanate constituting polyurethane component (u2)]
Examples of the aliphatic isocyanate constituting the polyurethane component (u2) include aliphatic organic polyisocyanates. Specific examples thereof include 1,6-hexamethylene diisocyanate and trimethylhexamethylene diisocyanate. Among these, 1,6-hexamethylene diisocyanate having a methylene chain is preferable.

  In addition, alicyclic isocyanates such as dicyclohexylmethane diisocyanate and isophorone diisocyanate (3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate) are treated as not belonging to any of the above.

[Polyol constituting polyurethane component (u1, u2)]
As the polyol constituting the polyurethane component (u1, u2), generally known polyols such as diols are used. Specific examples of this polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5- Relatively low molecular weight such as pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, trimethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexanedimethanol, methylpentane polyol adipate Polyester polyols such as polyester polyols, polyether polyols, polyester ether polyols, polycarbonate polyols, dimethylol propion, etc. A carboxyl group-containing polyol consisting of dimethylol alkanoic acids such as dimethylol butanoic acid and the like, may be used those of one or more.

[Vinyl polymer component (v)]
The said vinyl polymer component (v) means the homopolymer or copolymer of the vinyl monomer used as a raw material. Examples of the vinyl monomer component include (meth) acrylic monomers, vinyl halide compounds, polyfunctional unsaturated monomers, and aromatic vinyl compounds. In this specification, “(meth) acryl” means “acryl or methacryl”.

  The said (meth) acrylic-type monomer means (meth) acrylic acid or its ester compound, (meth) acrylic-acid alkylester, (meth) acrylic-type monomer, (meth) acrylic-acid alkoxyalkyl Examples thereof include esters and other (meth) acrylic monomers. In the polymerization, one of them may be used, or a mixture of two or more thereof may be used.

  Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth ) Cyclohexyl acrylate, benzyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, and the like.

  Examples of the alkoxyalkyl ester of (meth) acrylic acid include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, and the like.

  Examples of the other (meth) acrylic monomers include (meth) acrylonitrile and (meth) acrylamide.

  Examples of the vinyl halide compound include vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride. Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, and m-methylstyrene. , P-methylstyrene and the like.

  Examples of the polyfunctional unsaturated monomer include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof.

Further, in addition to the above, N, N-divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, and compounds having three or more vinyl groups can be mentioned.
In addition, the monomer which has said vinyl group may be used independently, and 2 or more types may be mixed and used for it.

[Polyurethane-vinyl polymer composite resin (A1, A2)]
The polyurethane-vinyl polymer composite resin refers to a composite resin with a polyurethane component and a vinyl polymer component (v). Specifically, the polyurethane-vinyl polymer composite resin (A1) refers to a composite resin comprising a polyurethane component (u1) and a vinyl polymer component (v), and the polyurethane-vinyl polymer composite resin (A2) is A composite resin comprising a polyurethane component (u2) and a vinyl polymer component (v).

[Production method of polyurethane component (u1, u2) and urethane resin (B1, B2)]
The polyurethane component (u1, u2) and the urethane resin (B1, B2) are produced by mixing the above-described specific polyvalent isocyanate and the polyol and causing a urethane reaction.

  The mixing ratio of the polyol and the polyvalent isocyanate is preferably a molar ratio of polyol / polyvalent isocyanate = 1 / 1.1 to 1 / 2.5, preferably 1 / 1.2 to 1/2. When there is more polyol than 1 / 1.1, the viscosity at the time of reaction will rise and the dispersion state to water may deteriorate. On the other hand, if it is less than 1 / 2.5, unreacted polyvalent isocyanate becomes excessive, and may aggregate during water dispersion or generate coarse particles.

  Next, this polyurethane component is dispersed in a hydrophilic medium which is water or a mixture of water and a hydrophilic organic solvent (methanol, ethanol, etc.) to obtain a polyurethane-based aqueous dispersion.

  The amount of the hydrophilic medium in this case is not particularly limited, but is preferably 0.5 to 9 times by weight and more preferably 1 to 4 times by weight with respect to the polyurethane component. When the amount is more than 9 times by weight, the content ratio of the resin tends to decrease and it becomes difficult to obtain a thick coating film. On the other hand, when the amount is less than 0.5 times by weight, the viscosity at the time of water dispersion increases, and the handleability may deteriorate.

  When obtaining this polyurethane-based aqueous dispersion, an emulsifier is used as necessary. Examples of the emulsifier include ionic surfactants such as anionic, cationic and amphoteric, nonionic surfactants, and the like.

  By the way, when the said polyurethane component contains a carboxyl group, neutralization with a basic compound is preferable because the resulting aqueous dispersion is more stabilized. The basic compound is not particularly limited as long as it can neutralize the carboxyl group, and includes alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, tertiary amines such as trimethylamine and triethylamine, and the like. can give.

[Production Method of Polyurethane-Vinyl Polymer Composite Resin (A1, A2)]
Next, a method for producing the polyurethane-vinyl polymer composite resin (A1, A2) will be described. As described above, the polyurethane-vinyl polymer composite resin (A1, A2) is a composite of the polyurethane component (u1, u2) and the vinyl polymer component (v). , U2), a vinyl monomer is added to a polyurethane aqueous dispersion composed of a polyurethane component, and then a method of vinyl polymerization, the above polyol, a specific polyvalent isocyanate, and a vinyl monomer are mixed. First, urethane polymerization is performed, and then vinyl polymerization is performed. Any method may be adopted. In the following, a method for mixing the above polyol, a specific polyvalent isocyanate, and a vinyl monomer, first performing urethane polymerization, and then performing vinyl polymerization will be described. .

  First, the specific polyvalent isocyanate, the polyol and the vinyl monomer are mixed and subjected to urethane reaction. Then, dispersion into a hydrophilic medium is performed. Various conditions for the urethane reaction and dispersion are the same as described above. When neutralization is necessary, a neutralization reaction is performed.

  Next, radical polymerization is performed using a radical polymerization initiator in the presence or absence of an emulsifier. When using an emulsifier, the emulsifier used for general emulsion polymerization can be used, and a nonionic, anionic, and cationic emulsifier can be illustrated.

  As said polymerization initiator, the polymerization initiator used by normal radical polymerization can be used. Examples of the polymerization initiator include persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvalero). Nitrile) and other azo compounds, hydrogen peroxide, hydroperoxides such as t-butyl hydroperoxide, radical polymerization initiators such as peroxides such as benzoyl peroxide and lauroyl peroxide, and these are independent. Or 2 or more types can be mixed and used. These radical polymerization initiators can be used as a redox polymerization initiator in combination with a reducing agent such as sodium sulfite, sodium hydrogen sulfite, sodium thiosulfate, tartaric acid, L-ascorbic acid.

  The polymerization temperature for the radical polymerization is preferably about 50 to 100 ° C. and the reaction time is usually about 2 to 16 hours.

  The content ratio of the polyurethane component and the vinyl polymer component is preferably a polyurethane component / vinyl polymer component = 10/90 or more, and preferably 30/70 or more, by weight. If it is smaller than 10/90, the elasticity of the resulting film tends to be insufficient. On the other hand, the upper limit of the content ratio is preferably 90/10, and preferably 70/30. When it is larger than 90/10, the film forming property tends to be lowered.

(Polyurethane resin composition)
The polyurethane-based resin composition according to the present invention includes a mixed resin of the polyurethane-vinyl polymer composite resin (A1) and the urethane resin (B2), a polyurethane-vinyl polymer composite resin (A1), and a polyurethane-vinyl. It is a resin composition containing a mixed resin of a polymer composite resin (A2) or a mixed resin of a polyurethane-vinyl polymer composite resin (A2) and a urethane resin (B1). That is, the skeleton derived from the polyvalent isocyanate contained in the total polyurethane content in the resin composition has a skeleton derived from the aromatic polyvalent isocyanate and a skeleton derived from the aliphatic polyvalent isocyanate.

  The compounding ratio of the skeleton derived from the aromatic isocyanate of the polyurethane component (u1) and the skeleton derived from the aliphatic isocyanate of the polyurethane component (u2) in the mixed resin is expressed as a molar ratio when expressed as (u1) / (u2). Therefore, (u1) / (u2) = 90/10 or less is preferable, and 70/30 or less is preferable. On the other hand, the lower limit of the compounding ratio is preferably 10/90, and preferably 30/70. Outside the above range, the balance between thick film formability and solvent resistance tends to deteriorate.

  In the mixed resin, the mixing ratio of the polyurethane-vinyl polymer composite resin (A1) and the urethane resin (B2), the polyurethane-vinyl polymer composite resin (A1), and the polyurethane-vinyl polymer composite resin. The mixing ratio with (A2) and the mixing ratio between the polyurethane-vinyl polymer composite resin (A2) and the urethane resin (B1) are the skeleton derived from the polyurethane component (u1) in the mixed resin and the polyurethane component ( If it is in the conditions which satisfy | fill the compounding ratio with frame | skeleton derived from u2), it will not specifically limit.

  Moreover, water dispersibility is securable because at least one part in the said all polyurethane content has frame | skeleton derived from a carboxyl group-containing polyol.

  In the present invention, a thick film can be formed by compounding urethane resins (B1 and B2) or polyurethane-vinyl polymer composite resins (A1 and A2) having urethane components (u1 and u2) having different isocyanate structural units. It is possible to obtain the effect that the solvent resistance (coexistence of alcohol resistance and acetone resistance) is improved.

  This is because, by mixing urethanes having different structural units, the film obtained therefrom tends to be hard to shrink with the urethane resin component derived from aliphatic isocyanate, which is an isocyanate that tends to shrink during film formation. Because of the presence of the aromatic isocyanate-derived urethane resin component, the shrinkage during film formation is alleviated, resulting in a synergistic effect that shrinkage is reduced as a whole and thick film formability is improved. is there. On the other hand, if both structural units are contained in the same urethane resin, the urethane resin tends to shrink due to the contraction of aliphatic isocyanate, which tends to shrink, and the entire film shrinks. is there.

  As for solvent resistance, the effects of improving alcohol resistance by aromatic isocyanate and improving acetone resistance by aliphatic isocyanate can be obtained in a balanced manner. If only an aromatic isocyanate that does not tend to shrink is used, the solvent resistance is insufficient.

  Examples of the physical properties include permanent elongation, elongation at break and area swelling ratio. In addition, these physical properties are calculated | required by the measuring method as described in a following example. The permanent elongation is preferably closer to 100%. On the other hand, the upper limit of permanent elongation is preferably 125% and preferably 110%. If it is larger than 125%, shape retention tends to be insufficient.

  The elongation at break is preferably 100% or more, and preferably 500% or more. If it is less than 100%, flexibility tends to be insufficient. On the other hand, the larger the elongation at break, the better.

  Furthermore, the said area swelling ratio says the area swelling ratio when each is immersed in isopropanol and acetone, 4 or less is good in any case, and 3 or less is preferable. If it is larger than 4, the solvent resistance is insufficient. The lower the swelling ratio, the better.

[Others]
In the polyurethane resin composition according to the present invention, in addition to the above-described components, other components may be mixed within a range that does not impair the effects of the present invention. Examples of other components include other types of polymers, stabilizers, fillers, antifungal agents, viscosity modifiers, dispersants, and the like. Examples of the other types of polymers include acrylic resin, styrene-butadiene rubber (SBR), ethylene-propylene-diene rubber (EPDM), polyvinyl acetate (PVAc), polyacrylonitrile (PAN), polystyrene (PS), and the like.

  The polyurethane resin composition thus obtained has sufficient thick film moldability and solvent resistance.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited by a following example, unless the summary is exceeded. First, the evaluation method and the raw materials used will be described.

(Evaluation method)
[Thick film formability]
A resin composition was applied on a glass plate so that the thickness of the film was about 100 μm, and was allowed to stand at room temperature overnight, then baked at 110 ° C. for 10 minutes, and then visually checked for cracks.
○: No occurrence of cracks △: Gradual whitening was observed (occurrence of fine cracks)
X: Crack occurred (micro crack or alligator crack occurred)

[SS test (breaking elongation test)]
The film obtained by the above thick film formability test is cut into a 0.5 cm wide strip, and the maximum elongation is measured under the following measurement conditions using an Autocom C type universal testing machine (manufactured by KSE Co., Ltd.). (%), 100% strength (MPa), and maximum strength (MPa) were measured.
Measurement conditions: Under an atmosphere of 23 ° C. and 50% Rh, a tensile speed of 200 mm / min is applied between 2 cm chucks.

[Permanent elongation]
The film obtained by the above thick film formability test was cut into a 1 cm × 5 cm strip and used as a test piece. The test piece was pulled to 10 cm within 15 seconds, held for 1 minute, and then rapidly contracted without rebounding, and the length after 1 minute was measured. And permanent elongation was computed from the following formula.
Permanent elongation = (length after shrinking 1 minute) (cm) / (initial length) (cm) × 100

[Solvent resistance]
-Area swelling ratio The film obtained in the above thick film formability test was cut into 1 cm x 5 cm, immersed in a solvent (isopropanol (IPA), acetone) for 30 minutes at room temperature, and the area was measured in a wet state. The area swelling ratio was calculated by the following formula.
Area swelling ratio = (Area in wet state) / 5

(raw materials)
[Polyisocyanate]
Hexamethylene diisocyanate: manufactured by Asahi Kasei Chemicals Corporation: Duranate 50M (trade name), hereinafter abbreviated as “HDI”.
Trimethylhexamethylene diisocyanate: manufactured by Degussa-Huls: VESTANAT TMDI (trade name), hereinafter abbreviated as “TMDI”.
Diphenylmethane diisocyanate: manufactured by Mitsui Chemicals, Inc .: Cosmonate PH (trade name), hereinafter abbreviated as “MDI”.

[Polyol] (Hereinafter, “OHV” means a hydroxyl value (unit: mgKOH / g).)
Polytetramethylene ether glycol: manufactured by Mitsubishi Chemical Corporation: PTMG1000, OHV: 112 mgKOH / g, hereinafter abbreviated as “PTMG (1000)”.
Polypropylene glycol: manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Hiflex D2000, OHV: 56 mgKOH / g, hereinafter abbreviated as “PPG (2000)”.
1, 4-butanediol: manufactured by Mitsubishi Chemical Corporation, hereinafter abbreviated as “14BG”.

[Acid diol]
Dimethylolpropionic acid: Mallinckrodt Chemical Inc. “DMPA” manufactured by the company.

[Vinyl monomer]
-Ethyl acrylate: manufactured by Mitsubishi Chemical Corporation, hereinafter referred to as "EA".
Acrylonitrile: manufactured by Diamond Nitrix Co., Ltd., hereinafter referred to as “AN”.
-2-methoxyethyl acrylate: Mitsubishi Chemical Corporation: ethyl acrylate DC-1, hereinafter referred to as "DC-1".
・ Butyl acrylate: manufactured by Mitsubishi Chemical Corporation, hereinafter referred to as “BA”.

[Stabilizer]
Hydroquinone monomethyl ether: Wako Pure Chemical Industries, Ltd .: Reagent, hereinafter referred to as “HQ”.

[Polymerization initiator]
-Redox initiator: 7 wt% t-butyl hydroperoxide aqueous solution (made by Kayaku Akzo Co., Ltd., hereinafter abbreviated as "PO") and 1 wt% ascorbic acid aqueous solution (Takeda Pharmaceutical Co., Ltd., (Hereinafter abbreviated as “AsA”).

[Others]
Neutralizing agent: triethylamine, manufactured by Wako Pure Chemical Industries, Ltd .: triethylamine, hereinafter abbreviated as “TEA”.
Solvent: methyl ethyl ketone, manufactured by Wako Pure Chemical Industries, Ltd .: 2-butanone, hereinafter abbreviated as “MEK”.

(Synthesis Examples 1-2)
In a four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, each component of each polyol shown in Table 1, each component of acid diol, vinyl monomer, and stabilizer are each in the amounts shown in Table 1. In addition, the internal temperature was set to 50 ° C., the amount of polyvalent isocyanate described in Table 1 was added, and the mixture was heated to 80 ° C. and reacted at this temperature for 5 hours to obtain a urethane prepolymer solution.
Subsequently, after adding the neutralizing agent of the quantity of Table 1 to this urethane prepolymer solution, distilled water was dripped over 15 minutes at 50 degreeC, and the milky white dispersion liquid was obtained.
Thereafter, the dispersion was kept warm at 50 ° C., and the initiator described in Table 1 was added to initiate vinyl polymerization. After completion of heat generation, the mixture was further heated to 70 ° C. and maintained for 3 hours to obtain an aqueous dispersion containing polyurethane and a vinyl polymer.

(Synthesis Example 3)
Into a four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, each polyol component and solvent shown in Table 1 were added in an amount shown in Table 1, the internal temperature was set to 50 ° C. The amount of polyvalent isocyanate was added, heated to 80 ° C., and reacted at this temperature for 5 hours to obtain a urethane prepolymer solution.
Subsequently, the neutralizing agent of the quantity of Table 1 was added to this urethane prepolymer solution, and distilled water was dripped over 15 minutes at 50 degreeC after that, and the milky white dispersion liquid was obtained.
Thereafter, this dispersion was heated to 90 ° C., a distillation apparatus was attached and desolvation was performed for 1 hour or more to obtain an aqueous urethane dispersion.

(Examples 1-2, Comparative Examples 1-3)
As shown in Table 2, the (A1) component, the (A2) component, and the (B2) component were mixed at the ratio shown in Table 2 to produce a resin composition. About the obtained resin composition, according to said method, it measured and evaluated about permanent elongation, breaking elongation, solvent resistance, and thick film formation. The results are shown in Table 2.

Claims (3)

A polyurethane-vinyl polymer composite resin (A1) comprising a polyurethane component (u1) having a structural unit derived from an aromatic isocyanate and a homopolymer or copolymer (v) of a (meth) acrylic monomer, and a fat From a urethane resin (B2) comprising a polyurethane component (u2) having a structural unit derived from an aliphatic isocyanate, or a homopolymer or copolymer (v) of the polyurethane component (u2) and (meth) acrylic monomer. A resin composition containing a mixed resin with a polyurethane-vinyl polymer composite resin (A2),
All polyurethane components which are all polyurethane components in the resin composition have a skeleton derived from a polyvalent isocyanate and a polyol,
At least a part of the total polyurethane content has a skeleton derived from a carboxyl group-containing polyol,
A polyurethane-based resin composition in which the content ratio of the skeleton derived from the aromatic isocyanate and the skeleton derived from the aliphatic isocyanate is 90/10 to 10/90 in terms of molar ratio. Permanent elongation 100-125%, and elongation at break 100 to 1000% and a polyurethane-based resin composition according to claim 1 area swelling ratio of isopropanol and acetone are both 4 or less. Polyurethane-based resin composition according to claim 1 or 2 which is an aqueous dispersion.