JPS6119618A - Thermosettable polyurethane resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improvements in thermosetting polyurethane resins, and more particularly to easily deformable polyurethane molded articles having delayed recovery properties. The soft, deformable material according to the invention is further characterized by low compression set and high temperature-insensitive damping properties over a wide temperature range.

BACKGROUND OF THE INVENTION Flexible polyurethanes which exhibit delayed recovery after compression are already known (GB 1.564,195). This polyurethane contains free hydroxyl groups and is obtained by reacting a polyol with a substoichiometric amount of isocyanate. Flexible polyurethanes can also be produced by introducing a significant excess of polyisocyanate over the amount required relative to the stoichiometric equivalent. This excess isocyanate acts as a plasticizer, but only if moisture is prevented from coming into contact with the product, which is of little practical value.

Problems to be Solved by the Invention It is an object of the present invention to overcome the disadvantages exhibited by conventional soft polyurethanes and to provide a substantial thermosetting polyurethane resin having good delayed recovery properties. It is to be.

Means for solving the problems, according to the present invention, provide (a) substantially primary hydroxyl
.

It has a sil group at the end and has a weight of 2,500 to 8. polyols with molecular weights in the range ooo, (b) polyvalent fluorocarbons (c
) High temperature-insensitive damping properties over a wide temperature range obtained by reacting an aliphatic monohydric primary alcohol having 10 or less carbon atoms and (d) a polyisocyanate with an incyanate index of 1.0 or more. exhibiting a tan δ greater than 0.1 over -40°C to 60°C, and a Shore A hardness within the range θ ~ 90, a compression set less than 15% and a tensile strength less than 30' kg/cm2. This objective can be achieved by a thermosetting polyurethane resin having a

The thermosetting polyurethane of the present invention is greater than 0.1, preferably greater than 0.2, in particular greater than 0.3, when measured over a temperature range of -40°C to 60°C by the method described below. It is necessary to have a large tan δ.

Furthermore, the polyurethane of the present invention has a compression set of less than 15%, preferably less than 10%, and a tensile strength of less than 30 kg/cx2, preferably less than 20 kg/cx2, as measured by the method described below.
AFI/c concentration is less than 2.

The polyol used in the present invention is 2 to 6, preferably 2 to 6.
It has a functionality in the range of 3 and 2,500
~s, ooo, preferably having a molecular weight in the range of 2,500 to 4,000.

The soft, easily deformable polyurethane of the present invention is configured to have improved energy attenuation properties. This is slightly cross-bonded polyurethane, but
Unlike the polyurethanes described in GB 1,564,195, for all practical purposes neither polyol nor polyisocyanate is fully reacted in excess. That is, the polyurethanes of the present invention do not contain free hydroxyl groups.

As is already known, the rate at which polyurethane hardness decreases is controlled by several actors, one of which is the isocyanate index.

For example, it is known that the rate of increase in hardness at an isocyanate index of 1.01 is faster than at an isocyanate index of 1.05.

And the optimum isocyanate index is about 1.03
This is the point. It is likewise known that the properties of polyurethanes can be modified by changing the structure of the polymer or by introducing fillers and plasticizers or a combination thereof. Catalysts that can be used to form the polyurethanes of the present invention include those commonly used in the production of polyurethanes, such as tertiary amines, compounds of tin, lead, mercury, iron, nickel or cobalt, tertiary amines. Examples include a mixture of and at least one of these metal compounds.

The properties of the polyurethanes of the invention are adjusted by varying the ratio of short chain diols to monohydric alcohols at a given polyol content.

In this way, the hardness of the resin can be varied from a dimensionally unstable semi-solid state to a solid having a Shore A hardness of approximately 90.

In many cases, it is preferable to use a resin having a Shore A hardness of 0 to 20. Such resin is
They are usually formed by reacting at room temperature, but higher curing temperatures may be used to achieve more rapid cross-linking. In this case, it is preferable to use the polyisocyanate in a stoichiometric amount, but if the polyisocyanate is used in a slightly larger amount than the required amount, there will be no significant adverse effect on the properties of the resin obtained under normal C conditions.

Furthermore, as is well known, polyurethane can also be formed via a prepolymer instead of the one-shot method described above. Further, part or all of the polyisocyanate can be replaced with a prepolymer having isocyanate groups at the ends.

Examples of polyisocyanates suitable for use in the present invention include diphenylmethane diisocyanate (MDI
), polymeric MDI, tolylene diisocyanate, cycloaliphatic diisocyanates such as nocyclohexylmethane diisocyanate, hexamethylene diisocyanate, p-phenylene diisocyanate and trans-1,4-cyclohexane diisocyanate.

Next, examples of polyhydric alcohols that can be used in the present invention include glycerin, 1,4-butanediol, pentaerythritol, trimethylolpronone, 1,2-propylene glycol, 1,6-hexanediol, 2-ethyl Hexane-1,3-diol, hydroquinone bis(hydroxyethyl ether) and the trade name [Pluriol Q (
Examples include tetrafunctional polyhydric alcohols such as Pluriol Q) J (manufactured by BASF), ]/, 11; ]]///-ethylenedinitrilotetra (2-propatol). Can be done. The polyhydric alcohol is preferably a short-chain diol, particularly one in which all of the hydroxyl groups are primary hydroxyl groups, such as 1,4-butanediol. Depending on the case, it is also possible to use a compound having a secondary hydroxyl group or a compound having both a primary hydroxyl group and a secondary hydroxyl group in the molecule.

Examples of suitable aliphatic monohydric primary alcohols include C1-C1o aliphatic primary alcohols, particularly C1-C1o aliphatic primary alcohols;
6, i.e. methyl alcohol to n-
Examples include hexanol. A monohydric ether alcohol with an equivalent weight of 155, known under the trade name "Thinner PU (1'hinner PU) J" (manufactured by Bayer AG), is also suitable for use in the present invention.Other monovalent active hydrogen Containing compounds such as thiols and mercaptans can also be used to replace some or all of the aliphatic monohydric primary alcohols, and mixtures of aliphatic monohydric primary alcohols can also be used.

The polyurethane of the present invention can be made into a foam according to conventional methods. For example, by applying high pressure to release gases dissolved in the resin, or by introducing a low-boiling liquid whose vapor pressure is significantly increased by external heating or by the chemical exotherm generated during the polymerization of the polyurethane.
Alternatively, the foam can be obtained by introducing a reactive liquid that generates a gas, such as water which reacts with a polyisocyanate to produce carbon dioxide. This foam is
Substantially either an open cell type or a closed cell type may be used.

Furthermore, it is possible to produce foams with a coating on the entire surface from the polyurethanes of the invention. It is also suitable for methods using mechanical whisking and methods for forming structural foams using micro hollow spheres.

According to the present invention, by preparing two types of masterbatch raw materials and mixing them in an appropriate ratio, a resin having desired properties or a resin having intermediate properties can be obtained for each hardness. It can be manufactured over a wide range of hardness without the need to prepare special compositions. This means that
This can also be accomplished by preparing a masterbatch for each combination, each with a composition that requires the same amount of polyisocyanate to provide the stoichiometric equivalent. This method is illustrated in the examples below.

The basic role played by the aliphatic monohydric primary alcohol or the mixture of monohydric alcohols in the present invention has been explained above. When the structure of this monohydric alcohol is systematically changed, it is observed that the compression set, hardness and elongation at break of the corresponding polyurethane gradually change.

Example Next, the present invention will be explained in more detail with reference to Examples.

(1) Measurement of tan δ Tan δ, defined as a loss factor in the international standard reference number ISO 2856-1975 (E), is a measure of the damping properties of a material.

A dynamic mechanical thermal analyzer (DMTA) was used for measurements.

Polymer Laboratories, Inc.) was used. The test conditions were as for normal clothing.

Bending mode test frequency 1 Hertz Heating rate 2°C/min Starting temperature -80°C Ending temperature +80°C (2) Tensile strength and elongation
)' determined by i.

(3) Compression set These are British National Standards 903, Part 86 (196
9), but the measurement conditions were changed to 25% strain at 40° C. for 20 hours.

(4) A hand-held hardness meter manufactured by AA Co., Ltd. was used for hardness measurement. Generally, two types of scales were used: Shore A and Sig700.

The values at both ends of these scales correspond to each other. For example, -2BAA "0" corresponds to Shore A00 "O", and Shore A "100" corresponds to Shore 00 "100". Shore 00 measurement range O~70 is Shore A θ
Shore 00 is used for measurements of low hardness, as it corresponds to ~20 and - provides better sensitivity.

In the examples, parts and percentages are by weight unless otherwise stated.

Example 1 The following two types of masterbatch compositions T N-43 and T
M01 was prepared.

Composition TM01 TM01 (
g> (y) n-butanol 30,0 0,
01.4-butanediol 0.0 1
8.2 Zeolis 50,0 5
0.0 Dioctyl phthalate 271.7 2
83.5□−□□□i□□□□□−□■−Gin■−Shizuku■Soto□R middle 1■■■■■■■■■■■−■■■■■■■
■−■■□Sotototal <g) 1
,400 1.400 mixing ratio (weight/weight)
10.0:1,0 10.0:1.0 As you can see, this masterbatch contains monohydric alcohol. Also, instead of n-butamele in TM01, an equivalent amount of methyl alcohol, ethyl alcohol, n
- A masterbatch composition was similarly prepared by using propatool and n-hexanol. In this example, two masterbatches were used in a constant ratio of 6:4. Experiments were then carried out by changing the type of monohydric alcohol and by changing the equivalent amount of the monohydric alcohol present in the composition. , masterbatch composition TN43
Necessary adjustments were made by varying the amount of dioctyl phthalate to keep the amount constant.

6 parts by weight of TM01 and 4 parts by weight of TN, 44 were mixed, and 10 parts by weight of the obtained masterbatch was mixed with 1 part by weight of Desmodur VL. The properties of the polyurethane resin thus obtained are shown in Table 1.

Table 1 (kg/c rough 2) (%) (%) Hardness Methyl alcohol 10.7 81.3 4.9
61 Ethyl alcohol 8.9 72 6
,9 57■Dobrobanol 14,0 9
3.3 9.0 4311-Butanol
9.3 105.7 9.2 4511-hex/-l 7.4 133,3 9.6
40 As is clear from Table 1, the compression set monotonically changes as the length of the carbon chain of the aliphatic alcohol increases.

In addition, the hardness of the obtained resin decreases as the length of the carbon chain of the aliphatic alcohol increases, reaching a minimum at n-propyl, and after that, even if the length of the carbon chain increases, the hardness decreases. does not appear to have a significant impact.

The elongation at break increases with increasing carbon chain.

Example 2 This example shows that the physical properties of polyurethane resins are influenced by changes in the proportion of reactive components, ie, the ratio of polyol:polyhydric alcohol di-primary alcohol.

In this example, polybutadiene with terminal hydroxyl groups is used as the polyol, and 1,
4-Butanediol and n-butanol were used as the primary alcohol in the amounts shown below.

Figure 1 shows the results of changes in hardness of the resin of each composition. As is clear from this figure, varying the proportions of the reactants results in the production of resins with a wide range of hardness.

Table 2 shows the t when the polybutadiene was maintained at 40% by weight and the ratio of butanediol to butanol was varied.
This shows the influence on anδ.

tan δ increases as the percentage of butanol increases, reaching -60' at a high level of butanol of 39% by weight.
Over a temperature range of C to +60'C, tan δ exhibits 0.30 or greater.

Example 3 This example is to demonstrate the effect of polyols on the physical properties of polyurethane resins.

In this example, several commercially available polyols were used as shown below.

Primary hydride type Functionality Roxyl group Molecular weight content (
%) 4S-HT Polybutadiene 2.5 100 3.00
0 (Alf product).

Polybutadiene: Polybutadiene with primary hydroxyl end groups F2805: Poly(propylene glycol) with ethylene oxide end groups F S 502: Poly(propylene glycol) with ethylene oxide end groups Examples of compositions based on polybutadiene are given in the examples. 1 and 2.

Examples of compositions based on F5502 are shown below.

The series based on F5502 consists of the following combinations.

EL45 and EL46 EL43 and EL44 EL47 and EL4. Q EL49 and EL50 The hardness curves of the resins thus obtained are shown in FIG.

Typical physical properties of resins selected from the above series and of the TN series are listed below.

Table 3 Mixture ratio Tensile strength Breaking elongation Compression permanent TN43:
TN44: Isocyanate) (kg/ex2) (%)
Strain 0: 10: 1 4, 1 285.0
5.84: 6: 1 7,5 13
0,0 7.89.5:0.5: 1 11,
3 62,0 20.7 No. 4 “Table Mixing ratio Tensile strength ゛Elongation at break Compression permanent EL43
:EL44: Butocyanate (kg/c shoulder 2) (%) Strain 8
: O: 1 13,7 37.0 0
．． 864: 4: 1 7,3 61,0
, 2.10: 8: 1 3.5
121.6 3.7 Table 5 Mixture ratio Tensile strength Elongation at break Compression permanent EL47:
EL48: Isocyanate (kg/cx2) (%) Strain 10:, O: 1 10.8 36,
7. - 0.863: ・7: 1 B, 5
52,0 2.310: 10: 1
4.3 61.7 3.16 Table 6 Mixing ratio Tensile strength Elongation at break Compression permanent EL49
:EL50 :Isocyanate (kg/c 2) (%) Strain 1
2.5: O:1 9.0 32.0
0.576: 6.5: 1 8.8 46,
0 0.560:12,5: 1 14.4
48.3 1.45 Effects of the Invention The raw materials for producing the polyurethane of the present invention can be easily blended using a conventional two-part mixing device, and can be prepared by mixing an appropriate composition or two types of master bunches. For example, by selecting a combination of EL45 and EL46,
It is possible to obtain a variety of resins ranging from hard, harsh solids to semi-solids with almost negligible dimensional stability.

The semisolid resin thus obtained is useful as a filler for vibration isolators. On the other hand, solid resins are used for similar purposes in areas where impact is applied or where energy is required. In addition, due to the low compression set, it is also used in equipment where sealing and strain resistance are important, especially in areas where the stiffness is combined with low modulus during compression (for example, 1 t at 50% compression).
MN#a2 or less, preferably 28 at 50% compression
Although it is used in places where the value is less than N/W', it is not necessarily limited thereto.

[Brief explanation of the drawing]

FIGS. 1 and 2 are graphs showing hardness curves of urethane resins of the present invention obtained in Examples.

Claims (1)

[Claims] 1 (a) polyol, (b) polyhydric alcohol, (c)
A monohydric alcohol and (d) a polyisocyanate, 1.
In a thermosetting polyurethane resin obtained by reaction with an isocyanate index of 0 or more, the polyol (a) has a molecular weight in the range of 2,500 to 8,000 and has substantially primary hydroxyl terminal groups. Polyol, the monohydric alcohol (c) above is an aliphatic monohydric primary alcohol having 10 or less carbon atoms, and exhibits high temperature-insensitive damping properties over a wide temperature range, from -40°C to 60°C.
tan δ greater than 0.1 over a temperature range of °C;
A polyurethane resin characterized in that it has a Shore A hardness in the range from 0 to 90, a compression set of less than 15% and a tensile strength of less than 30 kg/cm^2. 2. A polyurethane resin according to claim 1 obtained from a polyol having a functionality in the range of 2 to 6. 3. A polyurethane resin according to claim 2 obtained from a polyol having a functionality in the range of 2 to 3. 4. A polyurethane resin according to any one of claims 1 to 3 obtained from a polyol having a molecular weight in the range of 2,500 to 4,000. 5 C_1 to C_6 as aliphatic monohydric primary alcohols
The polyurethane resin according to any one of claims 1 to 4, which is obtained using a primary alcohol. 6 Claim 1 obtained by mixing two types of masterbatch raw materials and then reacting with polyisocyanate
The polyurethane resin according to any one of items 1 to 5. 7 0.3 over the temperature range -40°C to 60°C
The polyurethane resin according to any one of claims 1 to 6, which has a tan δ larger than . 8. A polyurethane resin according to any one of claims 1 to 7 having a Shore A hardness in the range of 80 to 20. 9. The polyurethane resin according to any one of claims 1 to 8, having a tensile strength of less than 20 kg/cm^2. 10. The polyurethane resin according to any one of claims 1 to 9, which has a compression set at room temperature of less than 10%.