阅读说明：本技术 聚氨酯树脂及其制备方法 (Polyurethane resin and preparation method thereof ) 是由 陈翠萍 潘念慈 宋维密 宋丽媛 李广佳 计成才 于 2021-10-19 设计创作，主要内容包括：本发明提供了一种聚氨酯树脂及其制备方法。所述聚氨酯树脂的制备方法包括将第一组分和第二组分混合制备所述聚氨酯树脂。其中所述第一组分由至少一种有机多元醇、丙烯酸酯单体和催化剂混合而成；所述第二组分由异氰酸酯和引发助剂混合而成；并控制所述第一组分和所述第二组分的重量比为100：(60-90),使得制备的聚氨酯树脂在25摄氏度下粘度为20-300毫帕.秒,可操作时间为50-200分钟的聚氨酯树脂,且所述聚氨酯树脂在70摄氏度下固化4小时的热变形温度大于60摄氏度。(The invention provides a polyurethane resin and a preparation method thereof. The preparation method of the polyurethane resin comprises the step of mixing a first component and a second component to prepare the polyurethane resin. Wherein the first component is formed by mixing at least one organic polyol, an acrylate monomer and a catalyst; the second component is formed by mixing isocyanate and an initiation auxiliary agent; and controlling the weight ratio of the first component to the second component to be 100: (60-90) so that the prepared polyurethane resin has a viscosity of 20-300 mpa.s at 25 ℃, a workable time of 50-200 minutes, and a heat distortion temperature of more than 60 ℃ at 70 ℃ for 4 hours of curing.)

1. A preparation method of polyurethane resin is characterized by comprising the following steps:

providing a first component and a second component;

mixing the first component and the second component to produce the polyurethane resin;

the first component is formed by mixing at least one organic polyol, an acrylate monomer and a catalyst;

the second component is formed by mixing isocyanate and an initiation auxiliary agent;

controlling the weight ratio of the first component to the second component to be 100: (60-90).

2. The method of claim 1, wherein the first component further comprises an alkenyl ester compound.

3. The method for producing a polyurethane resin according to claim 2, wherein the general structural formula of the alkenyl ester compound is:

wherein n is an integer of 1 to 5, and R1 is any one of a substituted or unsubstituted C2-C10 aliphatic alkyl group, a substituted or unsubstituted C2-C10 aliphatic alkyl group derivative, a substituted or unsubstituted alicyclic group derivative, a substituted or unsubstituted aromatic group, and a substituted or unsubstituted aromatic group derivative.

4. The method of claim 2, wherein the acrylate monomer has a general structural formula of:

wherein R2 is any one of substituted or unsubstituted C2-C10 aliphatic group, substituted or unsubstituted alicyclic group and substituted or unsubstituted aromatic group, and R3 is any one of hydrogen and substituted or unsubstituted C1-C10 alkyl group.

5. The method of preparing a polyurethane resin according to claim 2, wherein the step of providing the first component and the second component comprises:

controlling the viscosity of the mixture obtained after the first component is uniformly mixed to be 10-200 mPa.s at 25 ℃, and the hydroxyl value to be 200-.

6. The method as claimed in claim 5, wherein the step of controlling the viscosity of the mixture obtained by mixing the first component at 25 ℃ to be 10-200 mPa.s and the hydroxyl value to be 200-600 mg KOH/g comprises:

the weight ratio of the alkenyl ester compound to the at least one organic polyol is controlled to be 1 (6-12).

7. The method as claimed in claim 5, wherein the step of controlling the viscosity of the mixture obtained by mixing the first component at 25 ℃ to be 10-200 mPa.s and the hydroxyl value to be 200-600 mg KOH/g comprises:

controlling the weight ratio of the acrylate monomer to the at least one organic polyol to be 1: (1.7-2).

8. The method as claimed in claim 5, wherein the step of controlling the viscosity of the mixture obtained by mixing the first component at 25 ℃ to be 10-200 mPa.s and the hydroxyl value to be 200-600 mg KOH/g comprises:

controlling the weight percentage of the catalyst in the total amount of the at least one organic polyol and the acrylate monomer to be 0.05-0.2%.

9. The method as claimed in claim 5, wherein the step of controlling the viscosity of the mixture obtained by mixing the first component at 25 ℃ to be 10-200 mPa.s and the hydroxyl value to be 200-600 mg KOH/g comprises:

the hydroxyl value of the at least one organic polyol is controlled to be 100-700 mg potassium hydroxide/g, and the functionality is controlled to be 2-4.

10. The method as claimed in claim 5, wherein the step of controlling the viscosity of the mixture obtained by mixing the first component at 25 ℃ to be 10-200 mPa.s and the hydroxyl value to be 200-600 mg KOH/g comprises:

the hydroxyl value of the acrylate monomer is controlled to be 390-410 milligram potassium hydroxide/gram.

11. The method of preparing a polyurethane resin according to claim 2, wherein the step of providing the first component and the second component comprises:

and controlling the viscosity of the mixture obtained by uniformly mixing the second component to be 50-500 mPa.s at 25 ℃.

12. The method for preparing a polyurethane resin according to claim 11, wherein the step of controlling the viscosity of the mixture obtained by uniformly mixing the second component to be 50 to 500mpa.s at 25 ℃ comprises:

controlling the weight ratio of the isocyanate to the initiation auxiliary agent to be (47.5-50): 1.

13. the method for preparing a polyurethane resin according to claim 11, wherein the step of controlling the viscosity of the mixture obtained by uniformly mixing the second component to be 50 to 500mpa.s at 25 ℃ comprises:

controlling the weight percentage content of the isocyanate group of the isocyanate to be 28-35%.

14. The method of claim 1, wherein the at least one organic polyol is at least one of polyether polyol, polyester polyol, polyether ester polyol, polymer polyol, polycarbonate polyol, and polyether carbonate polyol.

15. A polyurethane resin produced by the method for producing a polyurethane resin according to claim 1.

16. The polyurethane resin of claim 15, wherein the polyurethane resin has a viscosity of 20 to 300 mpa.s at 25 degrees celsius and a workable time of 50 to 200 minutes, and wherein the workable time is the time taken for the viscosity of the polyurethane resin to increase to 500mpa.s per 175 grams of the polyurethane resin treated at a bath temperature of 30 degrees celsius.

Technical Field

The invention relates to the field of polyurethane, in particular to polyurethane resin and a preparation method thereof.

Background

Polyurethane is a high molecular compound and has the characteristics of rapid reaction and moderate tensile strength. At present, with the development of polyurethane resin, the polyurethane resin is widely applied to composite products with larger sizes, including composite pipelines and telegraph poles in winding production processes, composite grids and bridge supports in pultrusion production processes, automobile engine covers and wind-power blades in vacuum infusion processes, and the like, and in the application of the composite products, higher requirements are put forward on the operation period and the mechanical strength of the polyurethane resin. In the production of large-size composite material products, the polyurethane resin is required to have longer operable time so as to ensure that fiber reinforced materials such as glass fibers, carbon fibers and the like have better wettability in the production process to achieve higher composite material performance. However, the operable time of the conventional polyurethane resin, that is, the time for increasing the viscosity of 175g of polyurethane to 500mpa.s at 30 ℃ cannot be more than 50min, and the thermal deformation temperature of the casting body is generally lower than 60 ℃, so that a large-size composite product with the thickness of more than 5 cm and more than 10 meters cannot be prepared.

Therefore, it is required to provide a novel polyurethane resin to solve the above problems of the prior art.

Disclosure of Invention

The invention aims to provide polyurethane resin and a preparation method thereof, so as to obtain the polyurethane resin with the viscosity of 20-300 millipascal-seconds at 25 ℃ and the operable time of 50-200 minutes, and the thermal deformation temperature of the polyurethane resin is more than 60 ℃ when the polyurethane resin is cured at 70 ℃ for 4 hours.

In order to achieve the above object, the method for preparing a polyurethane resin of the present invention comprises the steps of:

providing a first component and a second component;

mixing the first component and the second component to produce the polyurethane resin;

the first component is formed by mixing at least one organic polyol, an acrylate monomer and a catalyst;

the second component is formed by mixing isocyanate and an initiation auxiliary agent;

controlling the weight ratio of the first component to the second component to be 100: (60-90).

The preparation method of the polyurethane resin has the beneficial effects that: the first component is formed by mixing at least one organic polyol, an acrylate monomer and a catalyst; the second component is formed by mixing isocyanate and an initiation auxiliary agent, the first component and the second component are mixed, and the weight ratio of the first component to the second component is controlled to be 100: (60-90) to obtain polyurethane resin with viscosity of 20-300 mPa.s at 25 ℃ and operable time of 50-200 min, and the thermal deformation temperature of the polyurethane resin is more than 60 ℃ when the polyurethane resin is cured at 70 ℃ for 4 hours.

The operational time of the present invention is defined as: the time for which the viscosity increased to 500mpa.s at 30 degrees celsius per 175g of polyurethane resin.

The viscosity of the polyurethane resin obtained by the preparation method is 20-300 mPa.s at 25 ℃, the operable time is 50-200 minutes, and the operable time of the polyurethane resin is the time for increasing the viscosity of every 175g of the polyurethane resin to 500mPa.s under the treatment of a water bath temperature of 30 ℃.

Further preferably, the polyurethane resin has a viscosity of 60 to 90 mpa.s at 25 ℃.

Further preferably, the polyurethane resin has a workable time of 70 to 110 minutes.

More preferably, the structural general formula of the alkenyl ester compound is as follows:

wherein n is an integer of 1 to 5, and R1 is any one of a substituted or unsubstituted C2-C10 aliphatic alkyl group, a substituted or unsubstituted C2-C10 aliphatic alkyl group derivative, a substituted or unsubstituted alicyclic group derivative, a substituted or unsubstituted aromatic group, and a substituted or unsubstituted aromatic group derivative.

More preferably, the structural formula of the acrylate monomer is:

wherein R2 is any one of substituted or unsubstituted C2-C10 aliphatic group, substituted or unsubstituted alicyclic group and substituted or unsubstituted aromatic group, and R3 is any one of hydrogen and substituted or unsubstituted C1-C10 alkyl group.

Further preferably, the substituted or unsubstituted aliphatic alkyl group having C2-C10 is any one of methyl, ethyl, n-propyl, isobutyl, sec-butyl, 3-pentyl, 2- (2-methyl) butyl, neopentyl, 2- (2-methyl) pentyl and hydroxymethyl.

Further preferably, the substituted or unsubstituted aromatic group is any one of tolyl, phenyl, phenolic, naphthyl, hydroxytoluene and phenylthio.

More preferably, the alkenyl ester compound is cyclohexyl allyl caproate, and the acrylate monomer is hydroxypropyl methacrylate. The cyclohexyl structure in the cyclohexyl allyl hexanoate increases the resistance to molecular interaction, decreasing the reaction rate when the first component and the second component are mixed; hydroxypropyl methacrylate inhibits the reaction of the at least one organic polyol and isocyanate herein.

Further preferably, the step of providing the first component and the second component comprises: controlling the viscosity of the mixture obtained after the first component is uniformly mixed to be 10-200 mPa.s at 25 ℃, and the hydroxyl value to be 200-; and controlling the viscosity of the mixture obtained by uniformly mixing the second component to be 50-500 mPa.s at 25 ℃.

Further preferably, the viscosity of the mixture obtained after the first component is mixed is controlled to be 10-200 mPa.s at 25 ℃, and the hydroxyl value is controlled to be 250-400 mg potassium hydroxide/g.

The first component is colorless or yellowish in appearance, and the mixture obtained by further adding a pigment and uniformly mixing has the viscosity of 10-200 mPa.s at 25 ℃ and the hydroxyl value of 250-400 mg of potassium hydroxide/g.

Further preferably, the step of controlling the viscosity of the mixture obtained by mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-: the weight ratio of the alkenyl ester compound to the at least one organic polyol is controlled to be 1 (6-12).

Further preferably, the step of controlling the viscosity of the mixture obtained by mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-: controlling the weight ratio of the acrylate monomer to the at least one organic polyol to be 1: (1.7-2).

Further preferably, the step of controlling the viscosity of the mixture obtained by mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-: controlling the weight percentage of the catalyst in the total amount of the at least one organic polyol and the acrylate monomer to be 0.05-0.2%.

Further preferably, the step of controlling the viscosity of the mixture obtained by mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-: the hydroxyl value of the at least one organic polyol is controlled to be 100-700 mg potassium hydroxide/g, and the functionality is controlled to be 2-4.

Further preferably, the step of controlling the viscosity of the mixture obtained by mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-: the hydroxyl value of the acrylate monomer is controlled to be 390-410 milligram potassium hydroxide/gram.

Further preferably, the organic polyol is at least one selected from the group consisting of polyether polyol, polyester polyol, polyether ester polyol, polymer polyol, polycarbonate polyol and polyether carbonate polyol.

Further preferably, the catalyst is copper naphthenate.

It is further preferred that the second component has a pale yellow to dark brown appearance and that different colorants can be added to change the color so that the viscosity is 50-500 cps.

Further preferably, the step of providing the first component and the second component comprises:

further preferably, the step of controlling the viscosity of the mixture obtained by uniformly mixing the second component to be 50 to 500mpa at 25 ℃ comprises the following steps: controlling the weight ratio of the isocyanate to the initiation auxiliary agent to be (47.5-50): 1.

the initiation aids described herein are not particularly limited and can be routinely selected by those skilled in the art.

Further preferably, the initiation aid is dibenzoyl peroxide.

Further preferably, the step of controlling the viscosity of the mixture obtained by uniformly mixing the second component to be 50 to 500mpa at 25 ℃ comprises the following steps: controlling the weight percentage content of the isocyanate group of the isocyanate to be 28-35%.

Further preferably, the isocyanate group content of the isocyanate is controlled to 31.5% by weight.

Further preferably, the isocyanate is a polyisocyanate.

In one embodiment, the method of preparing the polyurethane resin system comprises:

putting the at least one organic polyol, the alkenyl ester compound, the acrylate monomer and the catalyst into a reaction kettle, and uniformly stirring to obtain the first component;

adding the isocyanate and the initiation auxiliary agent into another reaction kettle, and uniformly stirring to obtain the second component;

mixing the first component and the second component to obtain the polyurethane resin.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. As used herein, the word "comprising" and similar words are intended to mean that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items.

The embodiment of the invention provides polyurethane resin and a preparation method thereof, which are used for obtaining the polyurethane resin with the viscosity of 20-300 millipascal-seconds at 25 ℃ and the operable time of 50-200 minutes, wherein the thermal deformation temperature of the polyurethane resin is higher than 60 ℃ when the polyurethane resin is cured for 4 hours at 70 ℃.

In order to achieve the above object, a method for preparing a polyurethane resin according to an embodiment of the present invention includes the steps of:

providing a first component and a second component;

mixing the first component and the second component to produce the polyurethane resin;

the first component is formed by mixing at least one organic polyol, an acrylate monomer and a catalyst;

the second component is formed by mixing isocyanate and an initiation auxiliary agent;

controlling the weight ratio of the first component to the second component to be 100: (60-90).

Specifically, the first component is formed by mixing at least one organic polyol, an acrylate monomer and a catalyst; the second component is formed by mixing isocyanate and an initiation auxiliary agent, the first component and the second component are mixed, and the weight ratio of the first component to the second component is controlled to be 100: (60-90) to obtain polyurethane resin with viscosity of 20-300 mPa.s at 25 ℃ and operable time of 50-200 min, and the thermal deformation temperature of the polyurethane resin is more than 60 ℃ when the polyurethane resin is cured at 70 ℃ for 4 hours.

The operable time of the embodiment of the invention is defined as: the time for which the viscosity increased to 500mpa.s at 30 degrees celsius per 175g of polyurethane resin.

The viscosity of the polyurethane resin obtained by the preparation method of the embodiment of the invention at 25 ℃ is 20-300 mPa.s, the operable time is 50-200 minutes, and the operable time of the polyurethane resin is the time for increasing the viscosity of every 175g of the polyurethane resin to 500mPa.s under the treatment of a water bath temperature of 30 ℃.

In some embodiments, the polyurethane resin has a viscosity at 25 degrees celsius of 60 to 90 millipascal-seconds.

In some embodiments, the polyurethane resin has a workable time of 70-110 minutes.

In the prior art, viscosity reducers such as dioctyl phthalate, dioctyl terephthalate, butyl benzyl phthalate and the like are often added to improve the operable time, but the addition of the viscosity reducers influences the crosslinking between the polyol and the isocyanate to a certain extent. In order to further solve the problems, the first component also comprises an alkene ester compound. The beneficial effects are that: it is advantageous to reduce the viscosity of the resulting polyurethane resin and to improve the working time.

In some embodiments, the alkenyl ester compound has the general structural formula:

wherein n is an integer of 1 to 5, and R1 is any one of a substituted or unsubstituted C2-C10 aliphatic alkyl group, a substituted or unsubstituted C2-C10 aliphatic alkyl group derivative, a substituted or unsubstituted alicyclic group derivative, a substituted or unsubstituted aromatic group, and a substituted or unsubstituted aromatic group derivative.

In some embodiments, the acrylate monomer has the general structural formula:

wherein R2 is any one of substituted or unsubstituted C2-C10 aliphatic group, substituted or unsubstituted alicyclic group and substituted or unsubstituted aromatic group, and R3 is any one of hydrogen and substituted or unsubstituted C1-C10 alkyl group.

In some embodiments, the substituted or unsubstituted C2-C10 aliphatic alkyl group is any one of methyl, ethyl, n-propyl, isobutyl, sec-butyl, 3-pentyl, 2- (2-methyl) butyl, neopentyl, 2- (2-methyl) pentyl, and hydroxymethyl.

In some embodiments, the substituted or unsubstituted aromatic group is any one of tolyl, phenyl, phenolic, naphthyl, hydroxytoluene, and thiophenyl.

In some embodiments, the alkenyl ester-based compound is allyl cyclohexylhexanoate and the acrylate monomer is hydroxypropyl methacrylate. The cyclohexyl structure in the cyclohexyl allyl hexanoate increases the resistance to molecular interaction, decreasing the reaction rate when the first component and the second component are mixed; hydroxypropyl methacrylate inhibits the reaction of the at least one organic polyol and isocyanate herein.

In some embodiments, the step of providing the first component and the second component comprises: controlling the viscosity of the mixture obtained after the first component is uniformly mixed to be 10-200 mPa.s at 25 ℃, and the hydroxyl value to be 200-; and controlling the viscosity of the mixture obtained by uniformly mixing the second component to be 50-500 mPa.s at 25 ℃.

In some embodiments, the viscosity of the mixture obtained after mixing the first component is controlled to be 10-200 mPa.s at 25 ℃ and the hydroxyl value is controlled to be 250-400 mg KOH/g.

In some embodiments, the first component is colorless or yellowish in appearance, and the mixture is blended with further colorant to provide a mixture having a viscosity of 10-200 mPa.s at 25 ℃ and a hydroxyl number of 250-.

In some embodiments, the step of controlling the viscosity of the mixture obtained after mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-600 mg koh/g comprises: the weight ratio of the alkenyl ester compound to the at least one organic polyol is controlled to be 1 (6-12).

In some embodiments, the step of controlling the viscosity of the mixture obtained after mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-600 mg koh/g comprises: controlling the weight ratio of the acrylate monomer to the at least one organic polyol to be 1: (1.7-2).

In some embodiments, the step of controlling the viscosity of the mixture obtained after mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-600 mg koh/g comprises: controlling the weight percentage of the catalyst in the total amount of the at least one organic polyol and the acrylate monomer to be 0.05-0.2%.

In some embodiments, the step of controlling the viscosity of the mixture obtained after mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-600 mg koh/g comprises: the hydroxyl value of the at least one organic polyol is controlled to be 100-700 mg potassium hydroxide/g, and the functionality is controlled to be 2-4.

In some embodiments, the step of controlling the viscosity of the mixture obtained after mixing the first component to be 10-200 mpa.s at 25 ℃ and the hydroxyl value to be 200-600 mg koh/g comprises: the hydroxyl value of the acrylate monomer is controlled to be 390-410 milligram potassium hydroxide/gram.

In some embodiments, the organic polyol is selected from at least one of polyether polyols, polyester polyols, polyetherester polyols, polymer polyols, polycarbonate polyols, and polyethercarbonate polyols.

Specifically, the polymer polyol, also called vinyl polymer graft polyether polyol, POP for short, is generally white or light opalescent in appearance, is a polyol containing an organic filler, can replace an inorganic filler, not only enables the polyurethane foam to have higher bearing capacity and good resilience, but also enables the foam cell structure and the physical and mechanical properties to be improved.

Functionality: the polymer functionality, the average number of reactive functional groups present on the polymer chain, is referred to as the functionality or average functionality of the polymer. Common active groups are hydroxyl-OH, carboxyl-COOH, allyl chloride, amino (amino) -NH2, and the like.

In some embodiments, the at least one organic polyol is (a) a polyether polyol having a functionality of 2 and (b) an organic polyol having a functionality of 3.

In some embodiments, the weight ratio of (a) the polyether polyol having a functionality of 2 and (b) the organic polyol having a functionality of 3 is 1: (0.3-2).

The (a) polyether polyol having a functionality of 2 and (b) organic polyol having a functionality of 3 described in this example are not particularly limited and may be selected by those skilled in the art in accordance with the disclosure herein.

Specific examples of the polyether polyol having a functionality of 2 (a) include uranol D204, Puranol D210, Puranol D220, Puranol D230, Puranol D240, Puranol D280 and Lupranol 1200.

Specific examples of the (b) organic polyol having a functionality of 3 include Puranol G303, Puranol G303F, Puranol G305, Puranol G306, Puranol G307, Puranol G310, Puranol G4030, Puranol G5030, and Voranol CP 455.

The catalyst described in this example is not particularly limited and may be selected conventionally by those skilled in the art.

In some embodiments, the catalyst is copper naphthenate.

In some embodiments, the second component is light yellow to dark brown in appearance, and different colorants may be added to change color such that the viscosity is 50-500 cps.

In some embodiments, the step of providing the first component and the second component comprises:

in some embodiments, the step of controlling the viscosity of the mixture at 25 degrees celsius of 50 to 500mpa.s obtained after blending the second component comprises: controlling the weight ratio of the isocyanate to the initiation auxiliary agent to be (47.5-50): 1.

the initiation aid described in this example is not particularly limited and may be routinely selected by those skilled in the art.

In some embodiments, the initiation aid is dibenzoyl peroxide.

In some embodiments, the step of controlling the viscosity of the mixture at 25 degrees celsius of 50 to 500mpa.s obtained after blending the second component comprises: controlling the weight percentage content of the isocyanate group of the isocyanate to be 28-35%.

In some embodiments, the isocyanate is controlled to have a weight percent isocyanate group content of 31.5%.

In some embodiments, the isocyanate is a polyisocyanate.

The kind of the polyisocyanate described in this example is not particularly limited, and those skilled in the art can select the polyisocyanate according to the description of the present application.

In one embodiment, the method of preparing the polyurethane resin system comprises:

putting the at least one organic polyol, the alkenyl ester compound, the acrylate monomer and the catalyst into a reaction kettle, and uniformly stirring to obtain the first component;

adding the isocyanate and the initiation auxiliary agent into another reaction kettle, and uniformly stirring to obtain the second component;

mixing the first component and the second component to obtain the polyurethane resin.

In some embodiments, the first component and the second component are packaged separately.

The present invention is described in detail below with reference to specific embodiments, but it should be understood that these examples are only illustrative and not restrictive. The starting materials used in the examples which follow are all commercially available unless otherwise stated.

Examples 1 to 5

Examples 1-5 of the present invention each provide a polyurethane resin system having the specific composition shown in Table 1 in parts by weight.

TABLE 1

In Table 1 (a) a polyether polyol having a functionality of 2 is available from Basf under the designation Lupranol 1200, (b) an organic polyol having a functionality of 3 is available from Dow under the designation Voranol CP 455, and an isocyanate is available from Dow under the designation Voracor CL 100.

The preparation method of the polyurethane resin system comprises the following steps:

(1) adding each raw material in the first component into a reaction kettle, starting a stirrer, and uniformly mixing;

(2) adding each raw material in the second component into another reaction kettle, starting a stirrer, and uniformly mixing;

(3) the first component and the second component are mixed.

Performance evaluation:

the polyurethane resin systems obtained in examples 1 to 5 were each tested, and the test results are shown in Table 2.

TABLE 2

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Also, where numerical ranges are used in the claims, subranges therein are included, and variations in these ranges are also to be construed as possible being covered by the appended claims.