JP6513340B2 - Heat resistant soundproofing material - Google Patents

Description

The present invention relates to a heat resistant sound insulation of polyurethane foam having excellent heat resistance.

  Although polyurethane foams are also used as soundproofing, general polyurethane foams, particularly ether polyurethane foams, are susceptible to oxidative degradation and have poor heat resistance, and may not be suitable depending on the place of use. For example, in vehicles, in order to suppress noise, soundproofing materials are used in various parts, but when used in the vicinity of an engine, etc., heat resistance is required.

  As a thing which raised the heat resistance of a polyurethane foam, there are a polyurethane foam (patent documents 1) impregnated with asphalt, an isocyanurate foam (patent documents 2), and a polycarbonate system polyurethane foam (patent documents 3).

Asphalt-impregnated polyurethane foam is manufactured by injecting a composition comprising a polyol, a polyisocyanate, a catalyst, a flame retardant, a blowing agent, asphalt and the like into a mold and foaming.
Isocyanurate foams are foams containing isocyanurate rings which are trimers of isocyanates. The isocyanurate ring is excellent in heat resistance and flame retardance because the stability of the bond is higher than that of a urethane bond.
The polycarbonate-based polyurethane foam is a polyurethane foam using a polycarbonate polyol having a polycarbonate group in the main chain, and is superior in heat resistance and hydrolysis resistance to general ether-based polyurethane foam and ester-based polyurethane foam.

However, polyurethane foam impregnated with asphalt is heavy and easily burnt due to the impregnated asphalt, and there is also a problem of stickiness at high temperature.
On the other hand, since isocyanurate foam contains a large amount of isocyanurate in the formulation of polyurethane foam, the foam tends to be brittle, and the hardness of the foam is high, so that it was not suitable as a soundproofing material for vehicles.
In addition, since the polycarbonate-based polyurethane foam has a very high raw material viscosity, it is difficult to handle at the time of production and is inferior in low temperature characteristics, and furthermore, there is a problem that the cost of the raw material is high.

Japanese Patent Publication No. 61-50965 Unexamined-Japanese-Patent No. 9-195415 gazette Japanese Patent Application Laid-Open No. 2005-60643

The present invention has been made in view of the above-mentioned point, and an object of the present invention is to provide a heat-resistant soundproofing material made of polyurethane foam which is excellent in heat resistance, has foam strength, is lightweight, easy to handle and inexpensive.

The invention according to claim 1 is a heat-resistant soundproofing material comprising a polyurethane foam obtained by reacting a polyol, a polyisocyanate and a foaming agent, wherein the polyol is an aliphatic dibasic acid having one or more alkyl side chains and a fat. Group having a trifunctional polyester polyol comprising a branched aliphatic alcohol and having a weight ratio of polyester polyol having at least one alkyl side chain, and polyether polyol is 100: 0 to 30:70, The agent is water, and the amount added is 1.5 to 4.0 parts by mass with respect to 100 parts by mass of the polyol, and the polyisocyanate is a single use of polymeric MDI, or a reaction between diphenylmethane diisocyanate and polyols. by either of the MDI prepolymer obtained by, 0.99 ° C., 600 hours Tensile strength retention which is defined in JIS K6400 before and after heating is characterized by a 70.6 to 109.1%.

  According to the invention of claim 1, since the polyol contains a polyester polyol having one or more side chains of an alkyl group, and the polyisocyanate contains diphenylmethane diisocyanate, the polyurethane foam is excellent in heat resistance and strong, and Since the asphalt is not impregnated, it is lightweight and easy to handle, and in addition, since it is not necessary to use expensive raw materials, the effect of becoming inexpensive can be obtained.

According to the invention of claim 1 , the cost can be reduced by using the polyether polyol in combination.
According to the invention of claim 1 , by using tolylene diisocyanate together, the viscosity of the raw material can be lowered to further improve the handleability.
According to the invention of claim 1 , heat resistant, strong, lightweight, inexpensive heat resistant soundproofing material can be obtained.

The polyurethane foam in the present invention is obtained by reacting a polyol and a polyisocyanate, and forms foam from a polyurethane raw material in which a polyol, a foaming agent, a catalyst, a foam stabilizer, a polyisocyanate, and other appropriate auxiliary agents are blended. Be done. The density of the polyurethane foam (JIS K 7222: 2005) is preferably ³⁰ to 150 kg / m ³ .

  The polyol used in the present invention includes a polyester polyol having one or more side chains of an alkyl group, and a polyether polyol may be used in combination. The mass ratio of the polyester polyol having one or more side chains of the alkyl group to the polyether polyol is preferably 100: 0 to 30:70, and particularly preferably used alone is a polyester polyol having one or more side chains of the alkyl group. In addition, you may use together multiple types of polyester polyol which has one or more side chains of an alkyl group. Moreover, it becomes possible to reduce a cost, without producing the extreme fall in the physical property of a polyurethane foam by using polyether polyol together in said range.

A polyester polyol having one or more alkyl side chains is a polymer having an aliphatic branched glycol and an aliphatic dicarboxylic acid as structural units.
Specifically, the aliphatic branched glycols include 1,2-propylene glycol, 1-methyl-1,3-butylene glycol, 2-methyl-1,3-butylene glycol, neopentyl glycol, 1-methyl-1, 4-pentylene glycol, 2-methyl-1,4-pentylene glycol, 1,2-dimethyl-neopentyl glycol, 2,3-dimethyl-neopentyl glycol, 1-methyl-1,5-pentylene glycol, 2 -Methyl-1,5-pentylene glycol, 3-methyl-1,5-pentylene glycol, 1,2-dimethylbutylene glycol, 1,3-dimethylbutylene glycol, 2,3-dimethylbutylene glycol, 1,4 -Dimethyl butylene glycol etc. can be illustrated. These aliphatic branched glycols may be used alone or in combination of two or more.
Specific examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid and dodecanedioic acid, 1,6-cyclohexanedicarboxylic acid and the like. In addition, derivatives such as these lower alkyl esters and acid anhydrides may also be mentioned. These may be used alone or in combination of two or more.
In addition, the average molecular weight (number average molecular weight) of the aliphatic polyester polyol obtained from the aliphatic dibasic acid and the aliphatic branched dihydric alcohol, which is a polyester polyol having one or more side chains of an alkyl group, is 1000 to 5000 (from Preferably, 2000 to 3000) aliphatic polyester polyols are preferred.
Moreover, as for the number of functional groups, 2 to 4 are preferable in order to make the softness and the toughness compatible.

  Examples of polyether polyols include ethylene oxide (EO) (polyethylene glycol) such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, sucrose, etc. And polyether polyols to which alkylene oxides such as propylene oxide (PO) are added. In particular, polyether polyols having a molecular weight of 2,000 to 7,000 and 2 to 6 functional groups are preferable.

  As the blowing agent, water or a hydrocarbon such as pentane can be used alone or in combination. In the case of water, carbon dioxide gas is generated during the reaction of the polyol and the polyisocyanate, and the carbon dioxide gas causes foaming. Although the quantity of a foaming agent is made appropriate, in the case of water, 1.5-4.0 mass parts is preferable with respect to 100 mass parts of polyols.

  As a catalyst, the well-known thing for urethane foams can be used. For example, mention may be made of amine catalysts such as triethylamine and tetramethylguanidine, tin catalysts such as stannas octoate, and metal catalysts such as phenylmercuric propionate or lead octenoate (also referred to as an organic metal catalyst). Can. The general amount of the catalyst is 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the polyol.

  As the foam stabilizer, those known for urethane foams can be used. For example, silicone based foam stabilizers, fluorine-containing compound based foam stabilizers and known surfactants can be mentioned. The general amount of the foam stabilizer is 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the polyol.

  The polyisocyanate includes diphenylmethane diisocyanate (MDI), and tolylene diisocyanate (TDI) may be used in combination. The mass ratio of diphenylmethane diisocyanate to tolylene diisocyanate is preferably 100: 0 to 30:70, and particularly preferably diphenylmethane diisocyanate (MDI) or polymeric MDI alone. In addition, diphenylmethane diisocyanate (MDI) may be used in combination of a plurality of prepolymers of monotric MDI, polymeric MDI and polymeric MDI. Moreover, by using tolylene diisocyanate together in the above-mentioned range, the viscosity of the polyurethane raw material can be lowered without causing an extreme decrease in the physical properties of the polyurethane foam, and the handleability can be further improved.

  Specifically as diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate (2,2'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 4,4'-diphenylmethane diisocyanate (4,4 4'-MDI), Polymeric MDI which is a mixture of diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate, MDI prepolymer obtained by reacting diphenylmethane diisocyanate and polyols, etc. can be mentioned.

  As tolylene diisocyanate (TDI), 2,4′-tolylene diisocyanate (2,4′-TDI), 2,6′-tolylene diisocyanate (2,6′-TDI), T-80 (2,4 There can be mentioned '-TDI / 2, 6'-TDI = 80/20) and T-65 (2, 4'-TDI / 2, 6'-TDI = 65/35). In particular, T-80 which is widely used for general purpose is preferable.

  The isocyanate index is preferably 90-105. When the isocyanate index is less than 90, a good foam can not be produced. On the other hand, when the isocyanate index exceeds 105, the foam becomes too hard or a good foam can not be produced. The isocyanate index is a value obtained by dividing the number of moles of isocyanate groups in the polyisocyanate by the number of moles of hydroxyl groups of the polyol and the total number of active hydrogen groups such as water as a foaming agent by 100 and multiplying [NCO equivalent of polyisocyanate / Equivalent hydrogen equivalent × 100].

Antioxidants, coloring agents and the like can be mentioned as auxiliary agents added as appropriate.
As an antioxidant, a phenol type, phosphorus type, diphenylamine type etc. can be mentioned, Especially any one of phosphorus type antioxidant and diphenylamine type antioxidant, or combined use is preferable. The amount of the antioxidant is preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the polyol.

The foaming method of the polyurethane foam of the present invention may be any known slab foaming or mold foaming.
Slab foaming is a method of discharging polyurethane raw material onto a conveyor, reacting polyol and polyisocyanate under normal temperature and atmospheric pressure, and continuously foaming it in the form of a bowl which swells upward, and then cut into appropriate dimensions. Ru.
On the other hand, mold foaming is a method of filling a mold with polyurethane raw material and foaming it into a product shape.

  The polyurethane foam of the present invention is used alone or laminated on a metal plate, a plastic plate or the like. Further, the polyurethane foam of the present invention is suitable for a member requiring heat resistance when used as a soundproofing material for vehicles, for example, a soundproof sheet on the back of an engine hood, an engine cover, an oil pan cover, etc. There is a use.

The polyurethane raw materials prepared in the formulations of Tables 1 and 2 using the following raw materials are mixed by a mixer, charged into a 400 × 400 × 40 mm foam mold, and foamed to obtain polyurethane foams of Examples and Comparative Examples. Manufactured.
Polyester polyol-1: poly (3-methyl-1,5 pentanediol; trimethylolpropane) alto-adipic acid, molecular weight 3,000, number of functional groups 3
Polyester polyol-2: poly (neopentyl glycol; trimethylolpropane) alto-adipic acid, molecular weight 3,000, number of functional groups 3
Polyesterpolyol-3: Poly (diethylene glycol / trimethylolpropane) alto-adipic acid, molecular weight 2400, functionality 2.6
Polyether polyol: polyoxyethylene / oxypropylene ether polyol, molecular weight 3,000, functional group number 3,
Foaming agent: Water Catalyst: Triethylenediamine Stabilizing agent: Special nonionic surfactant, BJ-100 (manufactured by Kao Corporation)
MDI-1: polymeric MDI, polymethylene polyphenyl polyisocyanate MDI-2: urethane modified MDI prepolymer, NCO% 28.5
TDI: T-80

Example 1 and Example 2 use only polyester polyol 1 having one or more side chains of alkyl group for polyols, use only polymeric MDI in Example 1 for polyisocyanate, and use Example 2 It is an example using only MDI prepolymer.
Example 3 is an example using only polyester polyol 2 which has one or more side chains of an alkyl group as a polyol, and using only polymeric MDI as a polyisocyanate.

  In Examples 4 and 5, 30 parts by mass (30% by mass in the polyol) of the polyester polyol 1 having one or more side chains of alkyl groups and 70 parts by mass (70% by mass in the polyol) of the polyether polyol In Example 4, only polymeric MDI is used for the polyisocyanate, and in Example 5, only the MDI prepolymer is used.

In Example 6, 30 parts by mass (30% by mass in the polyol) of the polyester polyol 2 having one or more alkyl side chains and 30 parts by mass (70% by mass in the polyol) of the polyether polyol are used in combination with the polyol. For polyisocyanate, it is an example using only polymeric MDI.
In Example 7, 30 parts by mass (30% by mass in the polyol) of the polyester polyol 1 having one or more alkyl side chains and 30 parts by mass (70% by mass in the polyol) of the polyether polyol are used in combination with the polyol. The polyisocyanate is an example in which 30% by mass of the polyisocyanate is polymeric MDI and 70% by mass is T-80.

The comparative example 1 is an example using only polyester polyol 1 which has one or more side chains of an alkyl group as a polyol, and using only T-80 as a polyisocyanate.
Comparative Example 2 and Comparative Example 3 use only polyester polyol 3 having 0 side chain of alkyl group for the polyol, and use only Polymeric MDI in Comparative Example 2 for the polyisocyanate and T in Comparative Example 3. This example is different from one another using only -80.
Comparative Example 4 uses only the polyester polyol 1 having one or more alkyl side chains for the polyol, and for the polyisocyanate, 20% by mass of the polyisocyanate in polymeric MDI, 80% by mass of T-80 and the like. Example.
In Comparative Example 5, 20 parts by mass (20% by mass in the polyol) of the polyester polyol 1 having one or more side chains of alkyl groups and 80 parts by mass (80% by mass in the polyol) of the polyether polyol are used in combination. For the polyisocyanate, it is an example using only polymeric MDI.
Comparative Examples 6 and 7 are examples in which only polyether polyol is used for the polyol, only Polymeric MDI is used in the Comparative Example 6 for the polyisocyanate, and only T-80 is used in the Comparative Example 7. .

  The heat resistance of each of the polyurethane foams of the examples and the comparative examples was measured. The measurement of heat resistance is carried out by measuring the tensile strength according to JIS K 6400 for the samples of urethane foam of each example and each comparative example, and then storing in a thermostat and heating at 150 ° C. for 600 hours Was measured according to JIS K 6400. Using the measured tensile strength before heating and the tensile strength after heating, the tensile strength retention (%) was calculated according to the formula of [tensile strength after heating ÷ tensile strength before heating × 100]. It was determined that the higher the tensile strength retention, the better the heat resistance. The results are shown at the bottom of Tables 1 and 2.

  From Tables 1 and 2, the polyurethane foams of Examples 1 to 7 had higher tensile strength retention than the polyurethane foams of Comparative Examples 1 to 7, and were excellent in heat resistance. Further, with regard to the polyol, from the comparison of Example 1 and Example 4 and the comparison of Example 2 and Example 5, it is understood that the alkyl group is more than the combined use of a polyester polyol having one or more alkyl side chains and a polyether polyol. It is understood that the use of a polyester polyol having one or more of side chains alone can improve heat resistance. On the other hand, it is understood from the comparison of Example 4 and Example 7 that polyisocyanate can use MDI alone more effectively than MD1 and TDI in combination.

Claims (1)

In a heat resistant soundproofing material comprising a polyurethane foam obtained by reacting a polyol, a polyisocyanate and a foaming agent,
The polyol includes a trifunctional polyester polyol consisting of an aliphatic dibasic acid having one or more alkyl side chains and an aliphatic branched dihydric alcohol, and a polyester polyol having one or more alkyl side chains; The mass ratio to the polyether polyol is 100: 0 to 30:70,
The foaming agent is water, and the addition amount is 1.5 to 4.0 parts by mass with respect to 100 parts by mass of the polyol,
The polyisocyanate is either a single use of polymeric MDI or an MDI prepolymer obtained by reacting diphenylmethane diisocyanate with polyols .
A heat-resistant and sound-proof material characterized by having a tensile strength retention rate of 70.6 to 109.1% as defined in JIS K6400 before and after heating at 150 ° C for 600 hours.