JP3416012B2 - Polyester resin, polyurethane resin and adhesive composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin, a polyurethane resin produced by using the polyester resin, and an adhesive composition produced by using the polyurethane resin.

[0002]

2. Description of the Related Art Conventionally, a polyurethane resin having a hydroxyl group or an isocyanate group at the molecular end obtained by reacting a polyester resin having a hydroxyl group at the molecular end with a polyisocyanate compound has a relatively good balance of physical properties. , Is widely used as a raw material for adhesives, sealing agents, paints and the like (hereinafter simply referred to as “adhesives and the like”).

On the other hand, with the recent widespread use of the adhesives and the like, polyester resins and polyurethane resins are
Small volume shrinkage, quick crystallization and rich initial cohesive force, final adhesive strength and flexibility, heat resistance, water resistance,
There is a strong demand for a wide range of advanced performance such as excellent weather resistance.

Various attempts have been made in order to meet the above demands. For example, in Japanese Patent Laid-Open No. 3-86719,
"A method for producing a urethane resin having an isocyanate group at a molecular end, which comprises reacting a linear aliphatic saturated polyester diol with polymethylene diisocyanate under an excess of polymethylene diisocyanate"
Is proposed.

However, in the method proposed above, for example, a linear aliphatic saturated polyester diol can be obtained by reacting succinic acid having 2 methylene groups with ethylene glycol having 2 methylene groups. When polyester diol is used, since the polyester diol is liquid at room temperature, the resulting urethane resin and adhesives using the same have poor initial cohesive strength, and are not applicable to applications requiring high performance. There is a problem that it does not exist.

In the method proposed above, for example, 1,10-decanedicarboxylic acid having 10 methylene groups and 1,10-having 10 methylene groups as the straight-chain aliphatic saturated polyester diol. When a polyester diol obtained by reacting with decane diol is used, the polyester diol is solid at room temperature and crystallized, so that the obtained urethane resin and adhesive have excellent initial cohesive strength, Poor flexibility,
There is a problem that the volumetric shrinkage becomes high and the resin layer is internally strained due to the volumetric shrinkage, so that floating or peeling easily occurs at the interface with the adherend.

Further, in order to address the above problems, as a straight-chain aliphatic saturated polyester diol, a dicarboxylic acid having 2 to 3 methylene groups and 6 to 10 methylene groups are used.
Or a diol having 6 to 10 methylene groups and a diol having 2 to 3 methylene groups are appropriately selected and reacted. Even if it is used, crystallization is necessary in order to exert a sufficient initial cohesive force, and when it is crystallized, there is a contradictory problem of poor flexibility and high volume shrinkage ratio, which is excellent. It is difficult to combine the initial cohesive force with excellent flexibility.

Further, for example, in Japanese Patent Laid-Open No. 63-199241, "Aromatic dicarboxylic acid component obtained by mixing isophthalic acid and terephthalic acid at a specific molar ratio, ethylene glycol and neopentyl glycol are mixed at a specific molar ratio. 100 parts by weight of a copolymerized aromatic polyester resin composed of the diol component and a specific amount of a triazine-based amino compound,
And an adhesive composition containing 1 to 20 parts by weight of a polyisocyanate compound as a main component has been proposed.

However, in the case of the adhesive composition according to the above proposal, since the aromatic polyester resin as the main component is amorphous, when the glass transition point is lower than room temperature, the initial cohesive force is insufficient, and conversely the glass transition is caused. If the point is higher than room temperature, there is a problem that it becomes hard and brittle and lacks flexibility.

Further, for example, in JP-A-5-51573, "Crystalline aliphatic polyester diol,
A hot melt adhesive composed of a urethane resin containing isocyanate groups at both ends which is obtained by reacting a polyol mixture with an aromatic polyester diol and diisocyanate has been proposed.

However, also in the case of the hot melt adhesive proposed above, in order to obtain a sufficient initial cohesive force, the proportion of the crystalline aliphatic polyester diol is increased or the glass transition temperature of the aromatic polyester diol is increased. As a result, there is a problem that flexibility becomes poor, volume shrinkage rate becomes large, and floating or peeling easily occurs at the interface with the adherend.

[0012] As described above, a polyester resin having both excellent initial cohesive force, small volume shrinkage and excellent flexibility, and a polyurethane resin produced using the polyester resin, and At present, an adhesive composition and the like produced using the polyurethane resin has not been put into practical use.

[0013]

In order to solve the above-mentioned conventional problems, the present invention has an excellent initial cohesive force, a small volume shrinkage ratio, and excellent adhesiveness, adhesive force, flexibility and the like. It is an object of the present invention to provide a polyester resin, a high-performance polyurethane resin produced using the polyester resin, and a high-performance adhesive composition produced using the polyurethane resin.

[0014]

The polyester resin according to the invention of claim 1 (hereinafter referred to as "first invention") is
Obtained by polycondensation reaction of a dicarboxylic acid component consisting of 10 to 60% by weight of terephthalic acid and 90 to 40% by weight of an aliphatic dicarboxylic acid and at least one diol component having 2 to 10 methylene groups, Further, it is characterized by having a hydroxyl group at the molecular end and having a number average molecular weight of 1,000 to 20,000.

The polyurethane resin according to claim 2 is
It is obtained by reacting the polyester resin according to the first invention with a polyisocyanate compound.

Further, the adhesive composition according to claim 3 is
It is characterized by being manufactured using the polyurethane resin according to the second invention.

The dicarboxylic acid component used as the raw material for the polyester resin according to the first invention is terephthalic acid 10
~ 60 wt% and aliphatic dicarboxylic acid 90-40 wt%
It must consist of

As described above, by using terephthalic acid and an aliphatic dicarboxylic acid in combination as the dicarboxylic acid component,
The resulting polyester resin has a structure in which terephthalic acid molecules, which are aromatic dicarboxylic acids, are incorporated in the skeleton of the aliphatic polyester diol, and therefore, the crystallinity of the aliphatic polyester diol is maintained, and the volume shrinkage ratio is small. It has excellent flexibility.

In the first invention, the aromatic dicarboxylic acid used in combination with the aliphatic dicarboxylic acid must be terephthalic acid. When the aromatic dicarboxylic acid is, for example, isophthalic acid, the resulting polyester resin does not have a linear skeleton, so that the crystallinity is impaired and the initial cohesive force becomes poor.

The aliphatic dicarboxylic acid used in combination with the terephthalic acid is not particularly limited, but for example, succinic acid, glutaric acid, adipic acid, suberic acid,
Azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,20-eicosanedicarboxylic acid, succinic anhydride, adipic anhydride, azelaine Acid anhydride, 1,10-decane dicarboxylic acid anhydride, glutaric acid dimethyl ester, suberic acid diethyl ester, sebacic acid dipropyl ester, 1,12-dodecane dicarboxylic acid diethyl ester, 1,20-eicosane dicarboxylic acid dimethyl ester And the like, and one or more of these are preferably used, and among them, adipic acid is more preferably used.

In the first invention, as the dicarboxylic acid component, terephthalic acid 10 to 6 which is an aromatic dicarboxylic acid is used.
0% by weight, preferably 10 to 80% by weight, and 90 to 40% by weight of the above aliphatic dicarboxylic acid, preferably 90 to 20%
%, Used together.

Less than 10% by weight of terephthalic acid,
Alternatively, when the amount of the aliphatic dicarboxylic acid exceeds 90% by weight, the volume shrinkage rate of the obtained polyester resin becomes large and the flexibility becomes poor.
More than wt% or 4 aliphatic dicarboxylic acids
When it is less than 0% by weight, the crystallinity of the obtained polyester resin is lowered and the initial cohesive force becomes poor.

The diol component used as a raw material for the polyester resin according to the first invention has a number of methylene groups of 2 to 2.
It must be at least one diol that is 10.

When the number of methylene groups of the above diol exceeds 10, the crystallinity of the obtained polyester resin becomes high and the volume shrinkage becomes large, and a polyurethane resin or an adherend when used as an adhesive composition is obtained. The adhesiveness, flexibility, etc. of the product become poor.

The diol having 2 to 10 methylene groups is not particularly limited, but for example, ethylene glycol, 1,3-propanediol,
1,4-butanediol, neopentyl glycol,
1,5-Pentane diol, 1,6-hexane diol, 1,8-octane diol, 1,10-decane diol and the like can be mentioned as preferred ones, among which 1,
6-hexanediol is more preferably used.

The above diols as the diol component may be used alone or in combination of two or more kinds.

The polyester resin according to the first invention has a hydroxyl group at the molecular end and has a number average molecular weight of 1,000 to 200.
It must be 00.

The polyester resin has a number average molecular weight of 1
If it is less than 000, the crystallization rate will be remarkably slowed, and it will be difficult to develop the initial cohesive force. On the contrary, if the number average molecular weight exceeds 20,000, the viscosity stability of the finally obtained adhesive or the like ( Storage stability) and applicability are reduced.

The method for obtaining a polyester resin having a hydroxyl group at the molecular end and a number average molecular weight of 1,000 to 20,000 is not special, and the dicarboxylic acid component and the diol component are polycondensed by a conventional method. When obtaining the polyester resin, if the amount of the dicarboxylic acid component charged is (n) mol, the amount of the diol component charged is (n +
1) By setting it as a mole, a hydroxyl group can be added to the molecular end of the obtained polyester resin.

Further, the charged amount (n) mol and (n +)
1) The number average molecular weight of polyester resin is 1000
The number average molecular weight of the obtained polyester resin is 1,000 to 2 by appropriately setting it to be 20,000.
It can be set to 0000.

The polyurethane resin according to the second invention is obtained by reacting the above-mentioned polyester resin according to the first invention with a polyisocyanate compound.

As the above polyisocyanate compound,
Although not particularly limited, for example, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate,
Xylylene diisocyanate, cyclohexane phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 1,5
-Naphthalene diisocyanate, 1,5-octylene diisocyanate and the like, and one or two of these
More than one kind is preferably used, and among them, MDI is more preferably used in terms of safety, easiness of handling and the like. still,
The above MDI is purified MDI, crude MDI, liquid modified MD
Any of I may be used.

The reaction ratio of the polyester resin according to the first aspect of the invention and the polyisocyanate compound is not particularly limited, but is [isocyanate group (NCO group) in the polyisocyanate compound / hydroxyl group (OH group in the polyester resin. )] Is preferably reacted at a molar ratio of 0.2 to 3.

If the NCO group / OH group molar ratio is less than 0.2, the molecular weight of the resulting polyurethane resin will be too large, which will impair processability and handleability. If the molar ratio of OH groups exceeds 3, the resulting polyurethane resin will have poor cohesive strength and flexibility.

When the NCO group / OH group molar ratio is 1 or less, the resulting polyurethane resin has a hydroxyl group at the terminal of the molecule. Conversely, when the NCO group / OH group molar ratio is greater than 1, The resulting polyurethane resin has an isocyanate group at the molecular end. Therefore,
By appropriately setting the above NCO group / OH group molar ratio, it is possible to freely obtain a polyurethane resin having a hydroxyl group or an isocyanate group at the molecular end.

The method for producing the polyurethane resin according to the second invention is not special, and for example, in a nitrogen atmosphere,
A desired polyurethane resin can be obtained by heating and melting a predetermined amount of the polyester resin according to the first invention, adding a predetermined amount of the polyisocyanate compound, and reacting them by a conventional method. At this time, a reaction catalyst such as amines or metal salts or a reaction aid may be used, if necessary.

The adhesive composition according to the third invention is produced by using the above-mentioned polyurethane resin according to the second invention.

The form of the adhesive composition according to the third invention is not particularly limited, and a solvent-type adhesive composition obtained by dissolving the polyurethane resin in an organic solvent or a solid polyurethane resin is heated and melted. Used as a hot-melt adhesive composition, a polyurethane resin in water, an emulsion-type adhesive composition obtained by emulsifying and dispersing by using a self-emulsifying or emulsifying agent or a surfactant, and a liquid polyurethane resin as it is The adhesive composition may be in any form such as a solvent-free liquid adhesive composition, but in order to fully exhibit the characteristics of the polyurethane resin according to the second invention, a solvent-based adhesive composition or hot melt It is preferably a mold adhesive composition.

The adhesive composition according to the third aspect of the invention comprises the second aspect.
Depending on the end group of the polyurethane resin according to the invention,
It can be used in various ways.

That is, when the polyurethane resin has a hydroxyl group at the molecular end, it may be used as a one-pack type adhesive composition in various forms described above, and various performances such as adhesive strength, heat resistance, water resistance, and weather resistance. In order to improve the above, for example, a compound having a functional group capable of reacting with a hydroxyl group such as the above-described polyisocyanate compound may be used as a crosslinking agent to form a two-component adhesive composition.

When the polyurethane resin has an isocyanate group at the molecular end, it may be used as a moisture-curable one-pack type adhesive composition in the various forms described above.
It may be used as a two-component adhesive composition in combination with a compound having a functional group capable of reacting with an isocyanate group such as a hydroxyl group or an amino group.

In the adhesive composition according to the third aspect of the invention, if necessary, a thermoplastic elastomer, tackifying resin, oil, etc. for improving the adhesiveness; Amine-based or tin-based catalysts for increasing the viscosity; various additives such as fillers, softeners, plasticizers, surfactants, wetting agents, thickeners, stabilizers, antioxidants, UV absorbers, colorants, etc. One or two or more of the agents may be contained.

The thermoplastic elastomer is not particularly limited, but is a styrene-conjugated diene block copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic ester copolymer, polyolefin, polyester, polyurethane. And the like, and one or more of these are preferably used.

The tackifying resin is not particularly limited, but it is rosin resin, terpene resin, styrene resin, coumarone-indene resin, aliphatic petroleum resin, alicyclic petroleum resin, aromatic. Examples include petroleum-based resins such as petroleum resins, styrene-based resins, coumarone-indene-based resins and the like, and one or more of these are preferably used. The softening point of the tackifying resin is not particularly limited, but is preferably 90 to 150 ° C. in the ring and ball softening point.

The above-mentioned oil is not particularly limited, and examples thereof include aromatic process oil, naphthene-based process oil, paraffin-based process oil, liquid paraffin and the like, and one or more of these are preferable. Among them, aromatic process oil is more preferably used.

The use of the adhesive composition according to the third invention is not particularly limited, but various uses such as automobile interiors, building material panels, furniture woodworking, bookbinding, fiber processing and the like can be mentioned. It is preferably used for any of these applications. Specific examples of the adherend include, but are not limited to, metals such as iron, copper, aluminum, tin plate, stainless steel, painted steel plate, and zinc steel plate, polyethylene, polypropylene, acrylic, ABS, vinyl chloride. , Synthetic resins such as polycarbonate, nylon, polystyrene, polyurethane, wood, plywood, particle board, cardboard,
Various adherends such as paper, non-woven fabric, and leather are mentioned, and they are preferably used for any of these adherends.

[0047]

The polyester resin according to the first invention comprises a dicarboxylic acid component comprising a specific amount of terephthalic acid (aromatic dicarboxylic acid) and a specific amount of aliphatic dicarboxylic acid, and a diol component having a specific number of methylene groups. Obtained by the polymerization reaction, and, since the number average molecular weight is in a specific range, it is possible to rapidly express the initial cohesive force due to crystallization, the volume shrinkage rate is small, and the excellent adhesiveness and adhesive force, Exhibits flexibility and the like.

The polyurethane resin according to the second invention is
Since it is obtained by reacting the polyester resin according to the first invention with a polyisocyanate compound, a hydroxyl group or an isocyanate group can be freely contained at the molecular end, and excellent initial cohesive force, small volume shrinkage ratio, and excellent Combines adhesion, adhesive strength, flexibility, etc.

Further, the adhesive composition according to the third invention is
Since it is made of the polyurethane resin according to the second aspect of the invention, it can be used in various forms and has excellent initial cohesive force, adhesion, adhesive force, flexibility and the like.

[0050]

BEST MODE FOR CARRYING OUT THE INVENTION The following examples are given to explain the present invention in more detail, but the present invention is not limited to these examples. In the examples, "part" means "part by weight", and "%" means "% by weight" unless otherwise specified.

(Example 1)

(1) Synthesis of polyester resin In a flask equipped with a dehydration circuit, 135 parts of a dicarboxylic acid component consisting of 102 parts of adipic acid (aliphatic dicarboxylic acid) and 33 parts of terephthalic acid and 1,6 as a diol component. After charging 118 parts of hexanediol (having 6 methylene groups) and adding 0.05 part of tetraisopropyl titanate as a reaction catalyst, an acid value of 1.0 or less and a water content of 0.
A polycondensation reaction was carried out at 220 ° C. until the content became not more than 06% to synthesize a polyester resin having a hydroxyl group at the molecular end. The number average molecular weight of the obtained polyester resin is 22.
00, the hydroxyl value was 51 KOHmg / g, and the acid value was 0.8.

(2) Synthesis of Polyurethane Resin The polyester resin obtained above was mixed with 9% nitrogen atmosphere.
After heating and melting at 0 to 150 ° C., 4,4′-diphenylmethane diisocyanate (MDI) is added so that the molar ratio of NCO group / OH group becomes 0.8, and the content of NCO group becomes 0%. Was reacted to synthesize a solid polyurethane resin having a hydroxyl group at the molecular end at room temperature.

(3) Preparation of Adhesive Composition 30 parts of the polyurethane resin obtained above was dissolved in 70 parts of methylene chloride to prepare a solvent-based adhesive composition having a solid content of 30%.

(4) Evaluation Performance of the adhesive composition obtained above (volume shrinkage-
A, adhesive strength-A, flexibility) were evaluated by the following methods. The results are shown in Table 1.

Volume Shrinkage-A A glass plate is coated with the adhesive composition to a thickness of 100 μm.
After being applied so as to be (wet), it was left to dry in an atmosphere of 20 ° C. for 24 hours. Then, the adhesion of the dry film to the glass plate was visually observed, and the volume shrinkage-A was evaluated according to the following criteria. [Criteria] ◎ ・ ・ ・ Adhesion to the glass plate was good, and no floating or peeling was observed ○ ・ ・ ・ No floating or peeling was observed from the glass plate, but the glass could not be removed by force. Peeling at the interface with the plate △ ・ ・ ・ Partially floating or peeling was observed × ・ ・ ・ Floating or peeling was entirely observed

Adhesiveness-A A vinyl chloride sheet (0.5 mm thick) was coated with an adhesive composition so that the coating thickness was 100 μm (wet), and then, in an undried state, with a birch material (8 mm thick). Adhesion test pieces were obtained by stacking and roll pressing with a linear pressure of 3 kg / cm. The obtained adhesive test piece was subjected to 2 in an atmosphere of 20 ° C. and 65% RH.
After curing for 4 hours, it was cut into a width of 25 mm to prepare a test piece for measurement. Next, the 180-degree peel strength (kgf / 25 mm) of the measurement test piece was measured at a pulling speed of 50 mm / min. Further, it was visually observed whether the peeling state at this time was cohesive failure or interfacial peeling.

A flexible steel sheet (0.8 mm thick, 10 cm square) was coated with the adhesive composition so that the coating thickness was 200 μm (wet), and then left in an atmosphere of 20 ° C. for 24 hours to dry. Then, a test piece for measurement in which the adhesive composition layer was provided on the steel plate was prepared. Then, the center line of the test piece for measurement was bent into a "V" shape, and the angle at which the adhesive composition layer peeled from the steel plate surface was measured. It can be said that the smaller the above angle, the better the adhesion to the steel plate and the more excellent the flexibility.

(Examples 2 to 4 and Comparative Examples 1 to 5) In the same manner as in Example 1 except that the composition for charging the dicarboxylic acid component and the diol component was changed to the composition shown in Table 1 in the synthesis of the polyester resin. As a result, eight kinds of polyester resins were obtained. The number average molecular weight, hydroxyl value and acid value of the eight types of polyester resins obtained were as shown in Table 1, respectively.

Then, eight kinds of polyurethane resins and adhesive compositions were obtained in the same manner as in Example 1 using the eight kinds of polyester resins obtained above.

The performance of the eight kinds of adhesive compositions obtained above was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 5 (1) Synthesis of Polyurethane Resin and Preparation of Adhesive Composition In the synthesis of polyurethane resin, the polyester resin obtained in Example 1 was heated and melted at 90 ° C. in a nitrogen atmosphere. , MCO was added so that the molar ratio of NCO group / OH group was 2.0 and reacted for 3 hours to obtain a polyurethane resin having an isocyanate group at the molecular end and solid at room temperature. The polyurethane resin obtained above was used as it was as a moisture-curable hot-melt adhesive composition.

(2) Evaluation The performance (solidification time, volume shrinkage-B, adhesive strength-B) of the adhesive composition obtained above was evaluated by the following methods. The results are shown in Table 2.

Solidification time The adhesive composition was heated and melted at 150 ° C., and a glass plate (2 m
(thickness m) and the coating thickness was 100 μm (dry), and immediately left in an atmosphere of 20 ° C. Then, corrugated paper (0.5 mm thick) is stuck by finger pressure every 30 seconds after the temperature of the adhesive composition layer reaches 100 ° C., the adhesive composition layer is cooled and solidified, and the corrugated paper is stuck. The time when it was not possible to match them was measured and set as the solidification time (minutes).

Volume Shrinkage-B The adhesive composition is applied onto a glass plate to a thickness of 100 μm.
After being coated so as to be (dry), it was left in an atmosphere of 20 ° C. for 24 hours. Next, the adhesiveness of the adhesive composition layer solidified by cooling to the glass plate was visually observed, and the volume contraction rate-B was evaluated according to the same criteria as in the case of the volume contraction rate-A.

Adhesive Strength-B A vinyl chloride sheet (0.5 mm thick) was coated with an adhesive composition melted at 120 ° C. so that the coating thickness was 50 μm (dry), and immediately thereafter, a cover material (8 mm thick). ) And was roll-pressed at a linear pressure of 3 kg / cm to obtain an adhesive test piece. The obtained adhesion test piece was cured in an atmosphere of 20 ° C.-65% RH for 1 hour and then cut into a 25 mm width to prepare a test piece for measurement. Then, the 180 ° peel strength (kgf / 25 m) of the test piece for measurement was measured at a pulling speed of 50 mm / min.
m) was measured. Further, it was visually observed whether the peeling state at this time was cohesive failure or interfacial peeling.

(Examples 6 to 8 and Comparative Examples 6 to 10)
As shown in Table 2, 8 kinds of polyurethane resins were synthesized in the same manner as in Example 5 using 8 kinds of polyester resins obtained in Examples 2 to 4 and Comparative Examples 1 to 5 to obtain 8 Various types of polyurethane resins were used as they were as a moisture-curable hot-melt adhesive composition.

The performance of the eight types of adhesive compositions obtained above was evaluated in the same manner as in Example 5. The results are shown in Table 2.

[0069]

[Table 1]

[0070]

[Table 2]

As shown in Table 1, each of the solvent-based adhesive compositions of Examples 1 to 4 according to the present invention has a small volume shrinkage ratio and excellent adhesiveness, adhesive strength and flexibility. Have.

On the other hand, a comparative example obtained from a polyester resin synthesized using a dicarboxylic acid component containing no terephthalic acid (Comparative Example 1) or having an amount of terephthalic acid of less than 10% by weight (Comparative Example 2). The solvent-based adhesive composition of 1 or Comparative Example 2 has a large volume shrinkage and is inferior in adhesion, adhesive strength, flexibility and the like. Also, the amount of terephthalic acid is 6
The solvent-based adhesive composition of Comparative Example 3 obtained from a polyester resin synthesized using a dicarboxylic acid component exceeding 0% by weight has poor adhesive strength (cohesive strength). Furthermore, the solvent-type adhesive composition of Comparative Example 4 obtained from a polyester resin having a number average molecular weight of less than 1000 is inferior in adhesive strength (cohesive force), and conversely obtained from a polyester resin having a number average molecular weight of more than 20,000. The solvent-based adhesive composition of Comparative Example 5 was
The adhesion, adhesive strength, flexibility, etc. are all inferior.

Further, as shown in Table 2, all of the moisture-curable hot-melt adhesive compositions of Examples 5 to 8 according to the present invention have an appropriate solidification rate, and thus have good workability. It has excellent initial cohesion, small volume shrinkage, and excellent adhesion and adhesion.

On the other hand, a comparative example obtained from a polyester resin synthesized using a dicarboxylic acid component containing no terephthalic acid (Comparative Example 6) or containing less than 10% by weight of terephthalic acid (Comparative Example 7). The moisture-curable hot-melt adhesive composition of 6 or Comparative Example 7 has a too fast solidification rate to give poor workability, and also has a large volume shrinkage ratio and poor adhesion and adhesive strength. Further, the moisture-curable hot melt adhesive composition of Comparative Example 8 obtained from the polyester resin synthesized by using the dicarboxylic acid component in which the amount of terephthalic acid exceeds 60% by weight, the solidification rate is too slow and the initial strength is low. (Initial cohesive strength) is lacking, and the adhesiveness and adhesive strength are poor. further,
The moisture-curable hot-melt adhesive composition of Comparative Example 9 obtained from a polyester resin having a number average molecular weight of less than 1000 lacked initial strength (initial cohesive force) due to too slow solidification rate, and at the same time, had poor adhesion (cohesion). In contrast, the moisture-curable hot melt adhesive composition of Comparative Example 10 obtained from a polyester resin having a number average molecular weight of more than 20,000 has a slightly large volumetric shrinkage ratio and poor adhesion and adhesive strength.

[0075]

As described above, the polyester resin according to the first aspect of the present invention can rapidly develop the initial cohesive force due to crystallization, has a small volume shrinkage rate, and has excellent adhesiveness, adhesive strength and flexibility. Since it exhibits flexibility and the like, it can be suitably used for various purposes including raw materials for synthesizing polyurethane resins.

The polyurethane resin according to the second invention is
Since it is produced using the polyester resin according to the first invention, it can freely contain a hydroxyl group or an isocyanate group at the molecular end, has a small volume shrinkage, and has excellent initial cohesive force, adhesiveness, adhesive force, It also has flexibility and the like, and is suitably used for various purposes including raw materials such as adhesives, sealing agents and paints.

Furthermore, the adhesive composition according to the third invention is
Since it is manufactured using the polyurethane resin according to the second invention, it can be used in various forms, has a small volume shrinkage, and has excellent initial cohesive force, adhesiveness, and adhesive force.
It also has flexibility and the like, and is suitably used for various applications such as automobile interiors, building material panels, furniture woodworking, bookbinding, and fiber processing.

Claims (3)

(57) [Claims] 1. A dicarboxylic acid component comprising 10 to 60% by weight of terephthalic acid and 90 to 40% by weight of an aliphatic dicarboxylic acid, and at least 1 having 2 to 10 methylene groups.
Obtained by a polycondensation reaction with a diol component of a species, and
Has a hydroxyl group at the molecular end and a number average molecular weight of 1000 to 2
A polyester resin characterized by being 0000. 2. A polyurethane resin obtained by reacting the polyester resin according to claim 1 with a polyisocyanate compound. 3. An adhesive composition made by using the polyurethane resin according to claim 2.