WO2023105969A1

WO2023105969A1 - Polyimide resin composition and molded body

Info

Publication number: WO2023105969A1
Application number: PCT/JP2022/039908
Authority: WO
Inventors: 敦史酒井; 勇希佐藤; 卓弥福島
Original assignee: 三菱瓦斯化学株式会社
Priority date: 2021-12-06
Filing date: 2022-10-26
Publication date: 2023-06-15
Also published as: JPWO2023105969A1; TW202337955A; CN118318009A

Abstract

The present invention provides: a polyimide resin composition which comprises a polyimide resin (A) that contains a repeating constituent unit represented by formula (1) and a repeating constituent unit represented by formula (2), with the content ratio of the repeating constituent unit represented by formula (1) to the total amount of the repeating constituent unit represented by formula (1) and the repeating constituent unit represented by formula (2) being 20-70 mol%, and an amorphous resin (B) that contains a repeating constituent unit represented by formula (I); and a molded body which comprises this polyimide resin composition. (In the formulae, R1 is a C6-C22 divalent group which comprises at least one alicyclic hydrocarbon structure; R2 is a C5-C16 divalent chain aliphatic group; and X1 and X2 are each independently a C6-C22 tetravalent group which comprises at least one aromatic ring.)

Description

Polyimide resin composition and molded article

The present invention relates to polyimide resin compositions and molded articles.

Polyimide resin is a useful engineering plastic with high thermal stability, high strength, and high solvent resistance due to the rigidity of the molecular chain, resonance stabilization, and strong chemical bonding, and is applied in a wide range of fields. Polyimide resins having crystallinity can further improve their heat resistance, strength and chemical resistance, and thus are expected to be used as metal substitutes. However, although the polyimide resin has high heat resistance, it does not show thermoplasticity and has a problem of low moldability.

As polyimide molding materials, highly heat-resistant resin Vespel (registered trademark) and the like are known (Patent Document 1). Since it is necessary to perform molding, it is also disadvantageous in terms of cost. On the other hand, a resin such as a crystalline resin that has a melting point and is fluid at high temperatures can be molded easily and inexpensively.

Therefore, in recent years, thermoplastic polyimide resins have been reported. Thermoplastic polyimide resins are excellent in moldability in addition to the inherent heat resistance of polyimide resins. Therefore, thermoplastic polyimide resins can also be applied to moldings used in harsh environments where general-purpose thermoplastic resins such as nylon and polyester could not be applied.
For example, in Patent Document 2, a predetermined A thermoplastic polyimide resin is disclosed that contains a repeating unit of

In the field of engineering plastics, there is also known a technique of compounding two or more thermoplastic resins into an alloy for the purpose of improving physical properties and adding functions according to the application. Patent Document 3 discloses a thermoplastic polyimide resin containing a predetermined repeating unit, and also describes the use of the polyimide resin in combination with another resin as a polymer alloy.

JP 2005-28524 A WO2013/118704 WO2016/147996

The thermoplastic polyimide resin described in Patent Document 3 has crystallinity and is excellent in heat resistance, strength, chemical resistance, etc., but depending on the application, a high level of dimensional stability in a wide temperature range is required. There was room for further improvement.
An object of the present invention is to provide a polyimide resin composition which has a low coefficient of linear thermal expansion and which can be used to form a molded article having excellent dimensional stability.

The present inventors have found that a polyimide resin composition containing a crystalline thermoplastic polyimide resin in which specific different polyimide structural units are combined in a specific ratio and an amorphous resin having a specific structure can solve the above problems. Found it.
That is, the present invention relates to the following.
[1] A repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2) are included, and the sum of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) Containing a polyimide resin (A) having a content ratio of 20 to 70 mol% of the repeating structural unit of the formula (1) and an amorphous resin (B) containing a repeating structural unit represented by the following formula (I) polyimide resin composition.

(R ₁ is a C 6-22 divalent group containing at least one alicyclic hydrocarbon structure. R ₂ is a C 5-16 divalent chain aliphatic group. _{X 1} and X ₂ are each independently a tetravalent group having 6 to 22 carbon atoms containing at least one aromatic ring.)

(R ₄ is a divalent group having 6 to 22 carbon atoms containing at least one aromatic ring; R ₅ is a divalent group represented by any of the following formulas (R-5a) to (R-5c) at least one of

(R ₅₁ is an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or _an alkynyl group having 2 to 4 carbon atoms; m ₅₁ is each independently an integer of 0 to 2; is an integer from 0 to 4. * indicates a bond.)

(each R ₅₂ is independently an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkynyl group having 2 to 4 carbon atoms; each _{m 52} is independently an integer of 0 to 2; and p ₅₂ are each independently an integer of 0 to 4. * indicates a bond.)

(each R ₅₃ is independently an alkyl group having 1 to 4 carbon atoms or a phenyl group; each _{m 53} is independently an integer of 2 to 6; n is the average number of repeating units; * is a bond; show hand.)
[2] A molded article containing the polyimide resin composition according to [1] above.

The polyimide resin composition and molded article of the present invention have a low coefficient of linear thermal expansion and excellent dimensional stability, and therefore are suitable for, for example, films, copper-clad laminates, electrical and electronic members that require a low coefficient of thermal expansion. .

FIG. 2 is a schematic diagram showing a method of preparing a sample used for observation with a field emission scanning electron microscope (FE-SEM); 1 is a micrograph of a cross section of the polyimide resin composition (pellet) of Example 2, cut in a direction perpendicular to the machine direction (MD), observed by FE-SEM.

[Polyimide resin composition]
The polyimide resin composition of the present invention comprises a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), wherein the repeating structural unit of the formula (1) and the formula (2) A polyimide resin (A) having a content ratio of 20 to 70 mol% of repeating structural units of the formula (1) with respect to the total repeating structural units of and an amorphous resin containing a repeating structural unit represented by the following formula (I) (B) and.

(each R ₅₃ is independently an alkyl group having 1 to 4 carbon atoms or a phenyl group; each _{m 53} is independently an integer of 2 to 6; n is the average number of repeating units; * is a bond; show hand.)

The polyimide resin composition of the present invention is a polyimide resin composition having a low coefficient of linear thermal expansion (hereinafter also referred to as “CTE”) and capable of producing a molded article having excellent dimensional stability. Although the reason for this is not certain, it is considered as follows.
Component (A) is a crystalline resin and component (B) is an amorphous resin, both of which have an imide structure. Therefore, component (A) and component (B) have mutual dispersibility, and in the resulting resin composition and molded article, they are mutually dispersed at the micro to nano level to form a microphase separation structure such as a sea-island structure. It is thought that there are A compact in which component (A) or component (B) is finely dispersed at the micro to nano level is likely to disperse stress even when stress is applied. be done. Furthermore, since component (A) and component (B) are resins having relatively high heat resistance among thermoplastic resins, it is believed that higher dimensional stability can be maintained even in a high temperature range.

Pellets made of the polyimide resin composition of the present invention, or molded articles obtained by molding the polyimide resin composition, preferably have a microphase-separated structure from the viewpoint of achieving a lower CTE. The microphase-separated structure is formed by phase separation of component (A) and component (B), and may be a sea-island structure or a co-continuous structure, but preferably a sea-island structure.
In the sea-island structure, either component may form the "sea" depending on the mass ratio of component (A) and component (B) in the compact.
In this specification, whether or not the pellet or molded body has a microphase-separated structure can be determined by observing the surface or cross section of the molded body with a scanning electron microscope (SEM).

<Polyimide resin (A)>
The polyimide resin (A) used in the present invention contains a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), and the repeating structural unit of the formula (1) and the formula ( The content ratio of the repeating structural units of formula (1) to the total repeating structural units of 2) is 20 to 70 mol %.

The polyimide resin (A) used in the present invention is a crystalline thermoplastic resin, and its form is preferably powder or pellets. The thermoplastic polyimide resin is formed by closing the imide ring after molding in the state of a polyimide precursor such as polyamic acid, for example, a polyimide resin having no glass transition temperature (Tg), or a temperature lower than the glass transition temperature It is distinguished from polyimide resin that decomposes at

The repeating structural unit of formula (1) is described in detail below.
R ₁ is a C 6-22 divalent group containing at least one alicyclic hydrocarbon structure. Here, the alicyclic hydrocarbon structure means a ring derived from an alicyclic hydrocarbon compound, and the alicyclic hydrocarbon compound may be saturated or unsaturated, and It may be cyclic or polycyclic.
Examples of the alicyclic hydrocarbon structure include, but are not limited to, cycloalkane rings such as cyclohexane ring, cycloalkene rings such as cyclohexene, bicycloalkane rings such as norbornane ring, and bicycloalkene rings such as norbornene. Do not mean. Among these, a cycloalkane ring is preferred, a cycloalkane ring having 4 to 7 carbon atoms is more preferred, and a cyclohexane ring is even more preferred.
R ₁ has 6 to 22 carbon atoms, preferably 8 to 17 carbon atoms.
R ₁ contains at least one, preferably 1 to 3, alicyclic hydrocarbon structures.

R ₁ is preferably a divalent group represented by the following formula (R1-1) or (R1-2).

(m ₁₁ and m ₁₂ are each independently an integer of 0 to 2, preferably 0 or 1; m ₁₃ to m ₁₅ are each independently an integer of 0 to 2, preferably 0 or 1.)

R ₁ is particularly preferably a divalent group represented by the following formula (R1-3).

In the divalent group represented by the above formula (R1-3), the positional relationship of the two methylene groups with respect to the cyclohexane ring may be cis or trans, and the ratio of cis to trans may be can be any value.

X ₁ is a tetravalent group having 6 to 22 carbon atoms containing at least one aromatic ring. The aromatic ring may be a single ring or a condensed ring, and examples include, but are not limited to, benzene ring, naphthalene ring, anthracene ring, and tetracene ring. Among these, benzene ring and naphthalene ring are preferred, and benzene ring is more preferred.
X ₁ has 6 to 22 carbon atoms, preferably 6 to 18 carbon atoms.
X ₁ contains at least one, preferably 1 to 3, aromatic rings.

X ₁ is preferably a tetravalent group represented by any one of formulas (X-1) to (X-4) below.

(R ₁₁ to R ₁₈ are each independently an alkyl group having 1 to 4 carbon atoms; p ₁₁ to p ₁₃ are each independently an integer of 0 to 2, preferably 0; p ₁₄ , p ₁₅ , p ₁₆ and p ₁₈ are each independently an integer of 0 to 3, preferably 0. p ₁₇ is an integer of 0 to 4, preferably 0. L ₁₁ to L ₁₃ are each independently a single bond, a carbonyl group or an alkylene group having 1 to 4 carbon atoms.)
Since X ₁ is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring, R ₁₂ , R ₁₃ , p ₁₂ and p ₁₃ in formula (X-2) are represented by formula (X- The number of carbon atoms in the tetravalent group represented by 2) is selected within the range of 10 to 22.
Similarly, L ₁₁ , R ₁₄ , R ₁₅ , p ₁₄ and p ₁₅ in formula (X-3) are in the range of 12 to 22 carbon atoms in the tetravalent group represented by formula (X-3). L ₁₂ , L ₁₃ , R ₁₆ , R ₁₇ , R ₁₈ , p ₁₆ , p ₁₇ and p ₁₈ in formula (X-4) are selected to contain tetravalent is selected so that the number of carbon atoms in the group is in the range of 18-22.

X ₁ is particularly preferably a tetravalent group represented by the following formula (X-5) or (X-6).

Next, the repeating structural unit of formula (2) will be described in detail below.
R ₂ is a divalent chain aliphatic group having 5 to 16 carbon atoms, preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, still more preferably 8 to 10 carbon atoms. Here, the chain aliphatic group means a group derived from a chain aliphatic compound, the chain aliphatic compound may be saturated or unsaturated, straight-chain It may be branched or branched.
R ₂ is preferably an alkylene group having 5 to 16 carbon atoms, more preferably an alkylene group having 6 to 14 carbon atoms, still more preferably an alkylene group having 7 to 12 carbon atoms, and most preferably an alkylene group having 8 to 10 carbon atoms. It is an alkylene group. The alkylene group may be a straight-chain alkylene group or a branched alkylene group, but is preferably a straight-chain alkylene group.
R ₂ is preferably at least one selected from the group consisting of an octamethylene group and a decamethylene group, and more preferably an octamethylene group.

_X2 is defined in the same manner as _X1 in Formula (1), and the preferred embodiments are also the same.

The content ratio of the repeating structural unit of formula (1) to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) is 20 to 70 mol %. When the content ratio of the repeating structural unit of formula (1) is within the above range, the polyimide resin can be sufficiently crystallized even in a general injection molding cycle. When the content ratio is less than 20 mol %, the moldability is deteriorated, and when it exceeds 70 mol %, the crystallinity is deteriorated and the heat resistance is deteriorated.
The content ratio of the repeating structural unit of formula (1) to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) is preferably 65 mol% or less from the viewpoint of expressing high crystallinity. More preferably 60 mol % or less, still more preferably 50 mol % or less, still more preferably less than 40 mol %.
When the content ratio of the repeating structural unit of the formula (1) to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is 20 mol% or more and less than 40 mol%, the polyimide resin (A) The crystallinity of is increased, and a resin molding having more excellent heat resistance can be obtained. The content ratio is preferably 25 mol% or more, more preferably 30 mol% or more, and still more preferably 32 mol% or more from the viewpoint of moldability, and is even more preferable from the viewpoint of expressing high crystallinity. is 35 mol % or less.

The total content ratio of the repeating structural units of the formula (1) and the repeating structural units of the formula (2) with respect to all repeating structural units constituting the polyimide resin (A) is preferably 50 to 100 mol%, more preferably 75 ~100 mol%, more preferably 80 to 100 mol%, still more preferably 85 to 100 mol%.

Polyimide resin (A) may further contain a repeating structural unit of the following formula (3). In that case, the content ratio of the repeating structural unit of formula (3) to the sum of the repeating structural units of formula (1) and the repeating structural units of formula (2) is preferably 25 mol % or less. On the other hand, the lower limit is not particularly limited as long as it exceeds 0 mol %.
When the repeating structural unit of formula (3) is contained, the content ratio is preferably 5 mol% or more, more preferably 10 mol% or more, from the viewpoint of improving heat resistance, while maintaining crystallinity. From the standpoint of doing so, it is preferably 20 mol % or less, more preferably 15 mol % or less.

(R ₃ is a C 6-22 divalent group containing at least one aromatic ring. X ₃ is a C 6-22 tetravalent group containing at least one aromatic ring.)

R ₃ is a C 6-22 divalent group containing at least one aromatic ring. The aromatic ring may be a single ring or a condensed ring, and examples include, but are not limited to, benzene ring, naphthalene ring, anthracene ring, and tetracene ring. Among these, benzene ring and naphthalene ring are preferred, and benzene ring is more preferred.
R ₃ has 6 to 22 carbon atoms, preferably 6 to 18 carbon atoms.
R ₃ contains at least one, preferably 1 to 3, aromatic rings.

R ₃ is preferably a divalent group represented by the following formula (R3-1) or (R3-2).

(m ₃₁ and m ₃₂ are each independently an integer of 0 to 2, preferably 0 or 1; m ₃₃ and m ₃₄ are each independently an integer of 0 to 2, preferably 0 or 1. R ₂₁ , R ₂₂ and R ₂₃ are each independently an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkynyl group having 2 to 4 carbon atoms. p ₂₁ , p ₂₂ and p ₂₃ are integers of 0 to 4, preferably 0. L ₂₁ is a single bond, a carbonyl group or an alkylene group having 1 to 4 carbon atoms.)
Since R ₃ is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring, m ₃₁ , m ₃₂ , R ₂₁ and p ₂₁ in formula (R3-1) are represented by formula (R3- It is selected so that the number of carbon atoms of the divalent group represented by 1) falls within the range of 6-22.
Similarly, L ₂₁ , m ₃₃ , m ₃₄ , R ₂₂ , R ₂₃ , p ₂₂ and p ₂₃ in formula (R3-2) have It is chosen to fall within the range of 12-22.

_X3 is defined in the same manner as _X1 in Formula (1), and the preferred embodiments are also the same.

Although the terminal structure of the polyimide resin (A) is not particularly limited, it preferably has a chain aliphatic group having 5 to 14 carbon atoms at its terminal.
The chain aliphatic group may be saturated or unsaturated, linear or branched. When the polyimide resin (A) has the above specific group at its terminal, a resin composition having excellent heat aging resistance can be obtained.
Examples of saturated chain aliphatic groups having 5 to 14 carbon atoms include n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, Lauryl group, n-tridecyl group, n-tetradecyl group, isopentyl group, neopentyl group, 2-methylpentyl group, 2-methylhexyl group, 2-ethylpentyl group, 3-ethylpentyl group, isooctyl group, 2-ethylhexyl group , 3-ethylhexyl group, isononyl group, 2-ethyloctyl group, isodecyl group, isododecyl group, isotridecyl group, isotetradecyl group and the like.
Examples of unsaturated chain aliphatic groups having 5 to 14 carbon atoms include 1-pentenyl group, 2-pentenyl group, 1-hexenyl group, 2-hexenyl group, 1-heptenyl group, 2-heptenyl group, 1- octenyl group, 2-octenyl group, nonenyl group, decenyl group, dodecenyl group, tridecenyl group, tetradecenyl group and the like.
Among them, the chain aliphatic group is preferably a saturated chain aliphatic group, and more preferably a saturated straight chain aliphatic group. From the viewpoint of obtaining heat aging resistance, the chain aliphatic group preferably has 6 or more carbon atoms, more preferably 7 or more carbon atoms, still more preferably 8 or more carbon atoms, and preferably 12 or less carbon atoms, more preferably 12 or less carbon atoms. has 10 or less carbon atoms, more preferably 9 or less carbon atoms. Only one type of chain aliphatic group may be used, or two or more types thereof may be used.
The chain aliphatic group is particularly preferably at least one selected from the group consisting of n-octyl group, isooctyl group, 2-ethylhexyl group, n-nonyl group, isononyl group, n-decyl group and isodecyl group. more preferably at least one selected from the group consisting of n-octyl group, isooctyl group, 2-ethylhexyl group, n-nonyl group and isononyl group, most preferably n-octyl group, isooctyl group and It is at least one selected from the group consisting of 2-ethylhexyl groups.
Moreover, from the viewpoint of heat aging resistance, the polyimide resin (A) preferably has only chain aliphatic groups having 5 to 14 carbon atoms at its terminals in addition to terminal amino groups and terminal carboxy groups. When a group other than the above is present at the terminal, the content thereof is preferably 10 mol % or less, more preferably 5 mol % or less, relative to the chain aliphatic group having 5 to 14 carbon atoms.

From the viewpoint of exhibiting excellent heat aging resistance, the content of the chain aliphatic group having 5 to 14 carbon atoms in the polyimide resin (A) is 100 in total of all repeating structural units constituting the polyimide resin (A). It is preferably 0.01 mol % or more, more preferably 0.1 mol % or more, and still more preferably 0.2 mol % or more based on mol %. In addition, in order to secure a sufficient molecular weight and obtain good mechanical properties, the content of the chain aliphatic group having 5 to 14 carbon atoms in the polyimide resin (A) is Preferably 10 mol% or less, more preferably 6 mol% or less, still more preferably 3.5 mol% or less, even more preferably 2.0 mol% or less, more preferably 100 mol% or less of all repeating structural units More preferably, it is 1.2 mol % or less.
The content of the chain aliphatic group having 5 to 14 carbon atoms in the polyimide resin (A) can be determined by depolymerizing the polyimide resin (A).

Polyimide resin (A) preferably has a melting point of 360° C. or lower and a glass transition temperature of 150° C. or higher. The melting point of the polyimide resin (A) is preferably 280° C. or higher, more preferably 290° C. or higher, from the viewpoint of heat resistance, and is preferably 345° C. or lower, more preferably 345° C. or lower, from the viewpoint of achieving high moldability. is 340° C. or less, more preferably 335° C. or less. Further, the glass transition temperature of the polyimide resin (A) is more preferably 160° C. or higher, more preferably 170° C. or higher from the viewpoint of heat resistance, and preferably 250° C. from the viewpoint of expressing high moldability. Below, more preferably 230° C. or less, and still more preferably 200° C. or less.
In addition, from the viewpoint of improving crystallinity, heat resistance, mechanical strength, and chemical resistance, the polyimide resin (A) is measured by a differential scanning calorimeter, and after melting the polyimide resin, it is cooled at a cooling rate of 20 ° C./min. The heat quantity at the crystallization exothermic peak (hereinafter also simply referred to as “crystallization exothermic value”) observed when the It is preferably 17.0 mJ/mg or more, and more preferably 17.0 mJ/mg or more. Although the upper limit of the crystallization heat value is not particularly limited, it is usually 45.0 mJ/mg or less.
The melting point, glass transition temperature, and crystallization heat value of the polyimide resin (A) can all be measured by a differential scanning calorimeter, and specifically by the methods described in Examples.

The weight average molecular weight Mw of the polyimide resin (A) is preferably 10,000 to 150,000, more preferably 15,000 to 100,000, still more preferably 20,000 to 80,000, still more preferably 30, 000 to 70,000, more preferably 35,000 to 65,000. When the weight-average molecular weight Mw of the polyimide resin (A) is 10,000 or more, the mechanical strength of the molded article obtained is good, and when it is 40,000 or more, the stability of the mechanical strength is good, It becomes easy to form the microphase-separated structure mentioned above, and a lower CTE can be achieved. Also, if it is 150,000 or less, moldability will be good.
The weight average molecular weight Mw of the polyimide resin (A) can be measured by a gel permeation chromatography (GPC) method using polymethyl methacrylate (PMMA) as a standard sample, and specifically can be measured by the method described in Examples. .

The logarithmic viscosity at 30° C. of a 0.5% by mass concentrated sulfuric acid solution of the polyimide resin (A) is preferably in the range of 0.8 to 2.0 dL/g, more preferably 0.9 to 1.8 dL/g. . When the logarithmic viscosity is 0.8 dL/g or more, sufficient mechanical strength can be obtained when formed into a molded article. When the logarithmic viscosity is 2.0 dL/g or less, molding processability and handleability are improved. The logarithmic viscosity μ is obtained from the following formula by measuring the flow times of concentrated sulfuric acid and the polyimide resin solution at 30° C. using a Canon Fenske viscometer.
μ = ln [(ts/t ₀ )/C]
t ₀ : Flow time of concentrated sulfuric acid ts: Flow time of polyimide resin solution C: 0.5 (g/dL)

(Method for producing polyimide resin (A))
Polyimide resin (A) can be produced by reacting a tetracarboxylic acid component and a diamine component. The tetracarboxylic acid component contains a tetracarboxylic acid and/or derivative thereof containing at least one aromatic ring, and the diamine component contains a diamine containing at least one alicyclic hydrocarbon structure and a linear aliphatic diamine. .

The tetracarboxylic acid containing at least one aromatic ring is preferably a compound in which four carboxy groups are directly bonded to the aromatic ring, and may contain an alkyl group in the structure. The tetracarboxylic acid preferably has 6 to 26 carbon atoms. Examples of the tetracarboxylic acid include pyromellitic acid, 2,3,5,6-toluenetetracarboxylic acid, 3,3′,4,4′-benzophenonetetracarboxylic acid, and 3,3′,4,4′-biphenyl. Tetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid and the like are preferred. Among these, pyromellitic acid is more preferable.

Derivatives of tetracarboxylic acids containing at least one aromatic ring include anhydrides or alkyl esters of tetracarboxylic acids containing at least one aromatic ring. The tetracarboxylic acid derivative preferably has 6 to 38 carbon atoms. Anhydrides of tetracarboxylic acids include pyromellitic monoanhydride, pyromellitic dianhydride, 2,3,5,6-toluenetetracarboxylic dianhydride, 3,3′,4,4′-diphenyl sulfonetetracarboxylic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 1,4,5, 8-naphthalenetetracarboxylic dianhydride and the like are included. Examples of alkyl esters of tetracarboxylic acids include dimethyl pyromellitic acid, diethyl pyromellitic acid, dipropyl pyromellitic acid, diisopropyl pyromellitic acid, dimethyl 2,3,5,6-toluenetetracarboxylate, 3,3′,4 ,4′-diphenylsulfonetetracarboxylate dimethyl, 3,3′,4,4′-benzophenonetetracarboxylate dimethyl, 3,3′,4,4′-biphenyltetracarboxylate dimethyl, 1,4,5,8 -Naphthalenetetracarboxylate dimethyl and the like. In the above alkyl ester of tetracarboxylic acid, the alkyl group preferably has 1 to 3 carbon atoms.

As the tetracarboxylic acid and/or derivative thereof containing at least one aromatic ring, at least one compound selected from the above may be used alone, or two or more compounds may be used in combination.

The diamine containing at least one alicyclic hydrocarbon structure preferably has 6 to 22 carbon atoms, such as 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4- Bis(aminomethyl)cyclohexane, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4'-diaminodicyclohexylmethane, 4,4'-methylenebis(2-methylcyclohexylamine) , carvonediamine, limonenediamine, isophoronediamine, norbornanediamine, bis(aminomethyl)tricyclo[5.2.1.0 ^2,6 ]decane, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, 4,4'-Diaminodicyclohexylpropane and the like are preferred. These compounds may be used alone, or two or more compounds selected from these may be used in combination. Among these, 1,3-bis(aminomethyl)cyclohexane can be preferably used. Diamines containing an alicyclic hydrocarbon structure generally have structural isomers, but the ratio of cis/trans isomers is not limited.

The chain aliphatic diamine may be linear or branched, and preferably has 5 to 16 carbon atoms, more preferably 6 to 14 carbon atoms, and still more preferably 7 to 12 carbon atoms. Chain aliphatic diamines such as 1,5-pentamethylenediamine, 2-methylpentane-1,5-diamine, 3-methylpentane-1,5-diamine, 1,6-hexamethylenediamine, 1,7-hepta methylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-trideca Methylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine, 2,2'-(ethylenedioxy)bis(ethyleneamine) and the like are preferred.
Chain aliphatic diamines may be used singly or in combination. Among these, chain aliphatic diamines having 8 to 10 carbon atoms can be preferably used, and at least one selected from the group consisting of 1,8-octamethylenediamine and 1,10-decamethylenediamine is particularly preferable. Available.

When producing the polyimide resin (A), the molar amount of the diamine charged containing at least one alicyclic hydrocarbon structure with respect to the total amount of the diamine containing at least one alicyclic hydrocarbon structure and the chain aliphatic diamine The ratio is preferably 20-70 mol %. The molar amount is preferably 25 mol% or more, more preferably 30 mol% or more, still more preferably 32 mol% or more, and from the viewpoint of expressing high crystallinity, preferably 60 mol% or less, more preferably 50 mol% or more. mol % or less, more preferably less than 40 mol %, more preferably 35 mol % or less.

In addition, the diamine component may contain a diamine containing at least one aromatic ring. The diamine containing at least one aromatic ring preferably has 6 to 22 carbon atoms, such as orthoxylylenediamine, metaxylylenediamine, paraxylylenediamine, 1,2-diethynylbenzenediamine, 1,3-diethynyl. Benzenediamine, 1,4-diethynylbenzenediamine, 1,2-diaminobenzene, 1,3-diaminobenzene, 1,4-diaminobenzene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4 ,4'-diaminodiphenylmethane, α,α'-bis(4-aminophenyl)1,4-diisopropylbenzene, α,α'-bis(3-aminophenyl)-1,4-diisopropylbenzene, 2,2- bis[4-(4-aminophenoxy)phenyl]propane, 2,6-diaminonaphthalene, 1,5-diaminonaphthalene and the like.

In the above, the molar ratio of the charged amount of the diamine containing at least one aromatic ring to the total amount of the diamine containing at least one alicyclic hydrocarbon structure and the chain aliphatic diamine is 25 mol% or less. It is preferably 20 mol % or less, still more preferably 15 mol % or less.
Although the lower limit of the molar ratio is not particularly limited, it is preferably 5 mol % or more, more preferably 10 mol % or more, from the viewpoint of improving heat resistance.
On the other hand, from the viewpoint of reducing the coloring of the polyimide resin, the molar ratio is more preferably 12 mol% or less, even more preferably 10 mol% or less, even more preferably 5 mol% or less, and even more preferably 0 mol %.

When producing the polyimide resin (A), the charged amount ratio of the tetracarboxylic acid component and the diamine component is preferably 0.9 to 1.1 mol of the diamine component with respect to 1 mol of the tetracarboxylic acid component. .

Moreover, when producing the polyimide resin (A), a terminal blocking agent may be mixed in addition to the tetracarboxylic acid component and the diamine component. As the terminal blocking agent, at least one selected from the group consisting of monoamines and dicarboxylic acids is preferable. The amount of the terminal blocking agent used may be an amount that can introduce a desired amount of terminal groups into the polyimide resin (A), and is 0.0001 to 0.001 to 0.001 to 1 mol of the tetracarboxylic acid and/or derivative thereof. 1 mol is preferable, 0.001 to 0.06 mol is more preferable, 0.002 to 0.035 mol is more preferable, 0.002 to 0.020 mol is even more preferable, 0.002 to 0.012 mol is even more preferred.
Among them, a monoamine terminal blocking agent is preferable as the terminal blocking agent, and from the viewpoint of improving heat aging resistance by introducing the chain aliphatic group having 5 to 14 carbon atoms described above at the end of the polyimide resin (A). , monoamines having a chain aliphatic group of 5 to 14 carbon atoms are more preferred, and monoamines having a saturated linear aliphatic group of 5 to 14 carbon atoms are even more preferred.
The terminal blocking agent is particularly preferably at least one selected from the group consisting of n-octylamine, isooctylamine, 2-ethylhexylamine, n-nonylamine, isononylamine, n-decylamine, and isodecylamine. , more preferably at least one selected from the group consisting of n-octylamine, isooctylamine, 2-ethylhexylamine, n-nonylamine, and isononylamine, most preferably n-octylamine, isooctylamine, and 2-ethylhexylamine.

As a polymerization method for producing the polyimide resin (A), a known polymerization method can be applied, and the method described in International Publication No. 2016/147996 can be used.

<Amorphous Resin (B)>
The amorphous resin (B) used in the present invention contains a repeating structural unit represented by the following formula (I).

(each R ₅₃ is independently an alkyl group having 1 to 4 carbon atoms or a phenyl group; each _{m 53} is independently an integer of 2 to 6; n is the average number of repeating units; * is a bond; show hand.)
By containing the polyimide resin (A) and the amorphous resin (B) having a specific structure, the polyimide resin composition of the present invention can produce a molded article with a low CTE.

In formula (I), R ₄ is preferably a C 12-22 divalent group containing two or more aromatic rings, more preferably the following formula (R- 4a) to (R-4c), preferably a divalent group represented by the following formula (R-4a).

(In the above formula, * indicates a bond.)

The alkyl group having 1 to 4 carbon atoms in R ₅₁ of formula (R-5a), R ₅₂ of formula (R-5b) and R ₅₃ of formula (R-5c) is methyl group, ethyl group, n-propyl , isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups.

In formula (R-5a), R ⁵¹ is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, still more preferably methyl, from the viewpoint of achieving a lower CTE. or an ethyl group, more preferably a methyl group. m ₅₁ is preferably 0 or 1, more preferably 0; p ₅₁ is preferably an integer from 0 to 2, more preferably 0 or 1, more preferably 0;

In formula (R-5b), R ₅₂ is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, still more preferably methyl, from the viewpoint of achieving a lower CTE. or an ethyl group, more preferably a methyl group. _m52 is preferably 0 or 1, more preferably 0; _p52 is preferably an integer from 0 to 2, more preferably 0 or 1, more preferably 0;

In formula (R-5c), R ₅₃ is each independently preferably a methyl group or a phenyl group, more preferably a methyl group, from the viewpoint of achieving a lower CTE. Each m ₅₃ is independently an integer of preferably 2 to 4, more preferably 3. n is preferably 2 or more and 5,000 or less.

R ₅ in formula (I) may have two or more divalent groups represented by any one of formulas (R-5a) to (R-5c).
From the viewpoint of achieving a lower CTE, R ₅ is preferably a divalent group represented by formula (R-5a), a divalent group represented by formula (R-5b), or a divalent group represented by formula (R-5a ) and a divalent group represented by formula (R-5c).

Specific examples of the amorphous resin (B) include an amorphous resin containing a repeating structural unit represented by the following formula (B1), an amorphous resin containing a repeating structural unit represented by the following formula (B2), and At least one selected from the group consisting of amorphous resins containing repeating structural units represented by formula (B3) can be used.

(In formula (B3), n is the average number of repeating structural units.)
Hereinafter, an amorphous resin containing a repeating structural unit represented by formula (B1) is referred to as "amorphous resin (B1)", and an amorphous resin containing a repeating structural unit represented by formula (B2) is referred to as "amorphous Resin (B2)”, and an amorphous resin containing a repeating structural unit represented by formula (B3) is also referred to as “amorphous resin (B3)”.

The melt flow rate (MFR) of the amorphous resins (B1) to (B3) is preferably within the following range from the viewpoint of improving the moldability of the polyimide resin composition and achieving a lower CTE.
The MFR of the amorphous resin (B1) measured at a temperature of 337° C. and a load of 6.6 kgf according to ASTM D1238 is preferably 5 to 20 g/10 minutes, more preferably 5 to 15 g/10 minutes. be.
The MFR of the amorphous resin (B2) measured at a temperature of 367° C. and a load of 6.6 kgf according to ASTM D1238 is preferably 10 to 30 g/10 minutes, more preferably 10 to 20 g/10 minutes. be.
The MFR of the amorphous resin (B3) measured at a temperature of 295° C. and a load of 6.6 kgf according to ASTM D1238 is preferably 3 to 20 g/10 minutes, more preferably 5 to 15 g/10 minutes. be.

The content of the repeating structural unit represented by the formula (I) (preferably the repeating structural unit represented by any one of the formulas (B1) to (B3)) in the amorphous resin (B) has a lower CTE and from the viewpoint of reducing water absorption, preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably It is 95% by mass or more and 100% by mass or less.

Component (B) can be used alone or in combination of two or more.
Among the above, the component (B) is preferably at least one selected from the group consisting of amorphous resins (B1) to (B3) from the viewpoint of achieving a lower CTE and reducing the water absorption rate. , more preferably at least one selected from the group consisting of the amorphous resin (B1) and the amorphous resin (B3), more preferably the amorphous resin (B3).

<mass ratio>
The mass ratio of the polyimide resin (A) to the total mass of the polyimide resin (A) and the amorphous resin (B) in the polyimide resin composition [(A) / {(A) + (B)}] is the present invention From the viewpoint of obtaining the effect of , it is preferably 0.01 or more and 0.99 or less. From the viewpoint of further reducing water absorption, the mass ratio is more preferably 0.1 or more, still more preferably 0.2 or more, still more preferably 0.25 or more, still more preferably 0.30 or more, and still more It is preferably 0.40 or more, still more preferably 0.45 or more, and from the viewpoint of achieving a lower CTE, it is more preferably 0.9 or less, still more preferably 0.8 or less, and even more preferably 0.8. It is 75 or less, more preferably 0.70 or less, still more preferably 0.60 or less, and even more preferably 0.55 or less.

The total content of the polyimide resin (A) and the amorphous resin (B) in the polyimide resin composition is preferably 50% by mass or more, more preferably 70% by mass or more, from the viewpoint of obtaining the effects of the present invention. It is preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass or less.

<Additive>
The polyimide resin composition of the present invention contains a filler, a reinforcing fiber, a matting agent, a nucleating agent, a plasticizer, an antistatic agent, an anti-coloring agent, an anti-gelling agent, a flame retardant, a coloring agent, a slidability improver, Additives such as antioxidants, ultraviolet absorbers, conductive agents, and resin modifiers may be contained as necessary.
The content of the additive is not particularly limited, but from the viewpoint of expressing the effect of the additive while maintaining the physical properties derived from the polyimide resin (A) and the amorphous resin (B), the polyimide resin composition , usually 50% by mass or less, preferably 0.0001 to 30% by mass, more preferably 0.0001 to 15% by mass, still more preferably 0.001 to 10% by mass.

Although the polyimide resin composition of the present invention can take any form, pellets are preferred.
Since the polyimide resin (A) and the amorphous resin (B) have thermoplasticity, for example, the polyimide resin (A), the amorphous resin (B), and optionally various optional components are melt-kneaded in an extruder. The strands can be extruded with a tumbler and pelletized by cutting the strands. Further, by introducing the obtained pellets into various molding machines and thermoforming them by the method described below, a molded article having a desired shape can be easily produced.

The glass transition temperature of the polyimide resin composition of the present invention, from the viewpoint of heat resistance, is preferably 160 ° C. or higher, more preferably 170 ° C. or higher, still more preferably 180 ° C. or higher, and from the viewpoint of expressing high moldability is preferably 250° C. or lower, more preferably 240° C. or lower. The glass transition temperature can be measured by a method similar to that described above.

<Coefficient of thermal expansion (CTE)>
According to the polyimide resin composition of the present invention, a low CTE molded article can be produced. For example, the absolute value of the linear thermal expansion coefficient measured according to JIS K7197: 2012 of a 4 mm thick molded body obtained by molding the polyimide resin composition is preferably 60 ppm / ° C. or less. .
The CTE measurement temperature range is 150 to 210 ° C. or 150 to 220 ° C., preferably 150 to 210 ° C. when the amorphous resin (B1) is used as the amorphous resin (B). When at least one selected from the group consisting of crystalline resins (B2) and (B3) is used, the range is 150 to 220°C.
Since the CTE value of a stretched molded article varies, the molded article used for CTE measurement is preferably a non-stretched molded article, more preferably an injection molded article.
Injection-molded articles also have a machine direction (MD) and a direction perpendicular to it (TD), and the MD and TD may have different CTEs. In this case, the absolute value of the coefficient of thermal expansion of at least one of MD and TD is preferably 60 ppm/°C or less, and more preferably the absolute value of the coefficient of thermal expansion of both MD and TD is 60 ppm/°C or less. preferable.

In an injection molded article having a thickness of 4 mm obtained by molding the polyimide resin composition, the absolute value of the linear thermal expansion coefficient, which is lower among MD and TD, is more preferably 55 ppm/° C. or less, more preferably 50 ppm/ ° C. or less, still more preferably 45 ppm/° C. or less, even more preferably 40 ppm/° C. or less, even more preferably 35 ppm/° C. or less, even more preferably 30 ppm/° C. or less, even more preferably 20 ppm/° C. or less, still more preferably It is preferably 15 ppm/°C or less, more preferably 10 ppm/°C or less.
Further, in an injection molded article having a thickness of 4 mm obtained by molding the polyimide resin composition, the total value of the absolute values of the thermal expansion coefficients in MD and TD is preferably 100 ppm/° C. or less, more preferably 95 ppm. /°C or less, more preferably 90 ppm/°C or less, even more preferably 80 ppm/°C or less, still more preferably 70 ppm/°C or less, and even more preferably 60 ppm/°C or less.
The linear thermal expansion coefficient of the molded product is a value measured in compression mode by thermomechanical analysis (TMA method), and can be specifically measured by the method described in Examples.

<Water absorption rate>
According to the polyimide resin composition of the present invention, a molded article with low water absorption can be produced. For example, the water absorption rate when immersed in water at 23 ° C. for 24 hours, measured in accordance with JIS K7209: 2000, of a molded body of 30 mm × 20 mm × thickness 4 mm obtained by molding a polyimide resin composition , preferably 0.30% or less, more preferably 0.25% or less, still more preferably 0.20% or less, and even more preferably 0.17% or less.
The water absorption rate is obtained from the following formula when the mass of the molded article before immersion in water is (W ₀ ) and the mass of the molded article after immersion in water at 23° C. for 24 hours is (W ₁ ). It is a calculated value.
Water absorption (%) = [(W ₁ -W ₀ )/W ₀ ] x 100
Specifically, the water absorption can be measured by the method described in Examples.

[Molded body]
The present invention provides a molded article containing the polyimide resin composition.
Since the polyimide resin composition of the present invention has thermoplasticity, the molded article of the present invention can be easily produced by thermoforming. Thermoforming methods include injection molding, extrusion molding, blow molding, hot press molding, vacuum molding, pressure molding, laser molding, welding, welding, etc. Any molding method involving a heat melting process can be used. is possible.
The molding temperature varies depending on the thermal properties (melting point and glass transition temperature) of the polyimide resin composition. For example, in injection molding, molding can be performed at a molding temperature of less than 400°C and a mold temperature of 220°C or less.

A method for producing a molded article preferably includes a step of thermoforming the polyimide resin composition at a temperature of less than 400°C. Specific procedures include, for example, the following method.
First, the polyimide resin (A), the amorphous resin (B), and optionally various optional components are added and dry blended, then introduced into an extruder, preferably melted at less than 400 ° C. The mixture is then melt-kneaded and extruded in an extruder to produce pellets. Alternatively, the polyimide resin (A) is introduced into the extruder, preferably melted at less than 400 ° C., and the amorphous resin (B) and various optional components are introduced into the extruder with the polyimide resin (A). The aforementioned pellets may be produced by melt-kneading and extrusion.
After drying the pellets, they can be introduced into various molding machines and thermoformed preferably at a temperature of less than 400° C. to produce a molded body having a desired shape.

The molded article of the present invention has a low coefficient of linear thermal expansion, excellent dimensional stability, and low water absorption. Therefore, it is suitable for, for example, films, copper-clad laminates, electrical and electronic members that require a low coefficient of thermal expansion. is.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these. In addition, various measurements and evaluations in each production example and working example were performed as follows.

<Infrared spectroscopic analysis (IR measurement)>
The IR measurement of the polyimide resin was performed using "JIR-WINSPEC50" manufactured by JEOL Ltd.

<Logarithmic Viscosity μ>
After drying the polyimide resin at 190 to 200 ° C. for 2 hours, 0.100 g of the polyimide resin was dissolved in 20 mL of concentrated sulfuric acid (96%, manufactured by Kanto Chemical Co., Ltd.). Measurements were made at 30°C using a meter. The logarithmic viscosity μ was determined by the following formula.
μ = ln [(ts/t ₀ )/C]
t ₀ : Flow time of concentrated sulfuric acid ts: Flow time of polyimide resin solution C: 0.5 g/dL

<Melting point, glass transition temperature, crystallization temperature, crystallization heat value>
The melting point Tm of the polyimide resin, and the glass transition temperature Tg, crystallization temperature Tc, and crystallization heat value ΔHm of the polyimide resin, amorphous resin, and polyimide resin composition were measured using a differential scanning calorimeter (SII Nanotechnology ( Measured using a "DSC-6220" manufactured by Co., Ltd.). In the measurement of the crystallization temperature Tc, the resin powder for the polyimide resin and the amorphous resin (B1), the amorphous resin (B2), the amorphous resin (B3), and the pellet for the polyimide resin composition were used as measurement samples. used as
In a nitrogen atmosphere, the measurement sample was subjected to thermal history under the following conditions. The thermal history conditions were a first temperature increase (temperature increase rate of 10° C./min), then cooling (temperature decrease rate of 20° C./min), and then a second temperature increase (temperature increase rate of 10° C./min).
The melting point Tm was determined by reading the peak top value of the endothermic peak observed the second time the temperature was raised. The glass transition temperature Tg was determined by reading the value observed at the second heating. The crystallization temperature Tc was determined by reading the peak top value of the exothermic peak observed during cooling. For Tm, Tg and Tc, when multiple peaks were observed, the peak top value of each peak was read.
The crystallization heat value ΔHm (mJ/mg) was calculated from the area of the exothermic peak observed during cooling.

<Semi-crystallization time>
The semi-crystallization time of the polyimide resin was measured using a differential scanning calorimeter ("DSC-6220" manufactured by SII Nanotechnology Co., Ltd.).
After holding at 420 ° C. for 10 minutes in a nitrogen atmosphere to completely melt the polyimide resin, when performing a rapid cooling operation at a cooling rate of 70 ° C./min, the peak top from the appearance of the observed crystallization peak. Calculate the time it took to reach In addition, in Table 1, when the semi-crystallization time was 20 seconds or less, it was described as "<20".

<Weight average molecular weight>
The weight average molecular weight (Mw) of the polyimide resin was measured under the following conditions using a gel permeation chromatography (GPC) measuring device "Shodex GPC-101" manufactured by Showa Denko KK.
Column: Shodex HFIP-806M
Mobile phase solvent: hexafluoroisopropanol (HFIP) containing 2 mM sodium trifluoroacetate
Column temperature: 40°C
Mobile phase flow rate: 1.0 mL/min
Sample concentration: about 0.1% by mass
Detector: IR detector Injection volume: 100 μm
Calibration curve: standard PMMA

<Water absorption rate>
Water absorption was measured according to JIS K7209:2000. Using the polyimide resin of Production Example 1, the amorphous resin, or the polyimide resin composition produced in each example, an injection molded body was produced by the method described later, and cut into a size of 30 mm × 20 mm × 4 mm in thickness. This was conditioned in an environment of 23° C. and relative humidity of 50% for 24 hours or longer before being used for measurement.
After the molded article was dried in a hot air circulation oven at 50°C for 24 hours, it was returned to room temperature in a desiccator, and the mass (W ₀ ) was measured under an environment of 23°C and a relative humidity of 50%. Subsequently, this molded body was immersed in water at 23° C. for 24 hours, and after wiping off the water on the surface, the mass (W ₁ ) was measured after 1 minute. The water absorption was calculated based on the following formula, and Table 2 shows the average value of three measurements.
Water absorption (%) = [(W ₁ -W ₀ )/W ₀ ] x 100

<Coefficient of thermal expansion (CTE)>
CTE was measured according to JIS K7197:2012. Using the polyimide resin of Production Example 1, the amorphous resin, or the polyimide resin composition produced in each example, an injection molded body is produced by the method described later, cut into a size of 5 mm × 4 mm × 10 mm, and used for measurement. bottom.
Using the above injection molded product as a measurement sample, a thermomechanical analyzer "TMA7100C" manufactured by Hitachi High-Tech Science Co., Ltd. was used in a nitrogen stream (150 mL/min) in a compression mode with a load of 49 mN and a heating rate of 5 ° C./min. The temperature was raised from 23 to 300° C. under the conditions of , and thermomechanical analysis (TMA) was measured. TMA measurements were performed in the machine direction (MD) and the direction perpendicular to it (TD) of the injection molded product, and the CTE was determined from the measured values at 150 to 210°C or 150 to 220°C.

Production Example 1 (Production of Polyimide Resin 1)
In a 2 L separable flask equipped with a Dean-Stark apparatus, a Liebig condenser, a thermocouple, and four paddle blades, 500 g of 2-(2-methoxyethoxy) ethanol (manufactured by Nippon Nyukazai Co., Ltd.) and pyromellitic dianhydride ( 218.12 g (1.00 mol) of Mitsubishi Gas Chemical Co., Ltd.) was introduced, and after nitrogen flow, the mixture was stirred at 150 rpm to form a uniform suspension. On the other hand, using a 500 mL beaker, 49.79 g (0.35 mol) of 1,3-bis(aminomethyl)cyclohexane (Mitsubishi Gas Chemical Co., Ltd., cis/trans ratio = 7/3), 1,8- A mixed diamine solution was prepared by dissolving 93.77 g (0.65 mol) of octamethylenediamine (manufactured by Kanto Chemical Co., Ltd.) in 250 g of 2-(2-methoxyethoxy)ethanol. The mixed diamine solution was added slowly using a plunger pump. Heat was generated by the dropwise addition, but the internal temperature was adjusted to be within the range of 40 to 80°C. During the dropwise addition of the mixed diamine solution, nitrogen flow was maintained and the rotation speed of the stirring blade was 250 rpm. After the dropping was completed, 130 g of 2-(2-methoxyethoxy)ethanol and 1.284 g (0.010 mol) of n-octylamine (manufactured by Kanto Kagaku Co., Ltd.) as a terminal blocker were added and further stirred. . At this stage, a pale yellow polyamic acid solution was obtained. Next, after setting the stirring speed to 200 rpm, the polyamic acid solution in the 2-L separable flask was heated to 190°C. In the process of increasing the temperature, deposition of polyimide resin powder and dehydration due to imidization were confirmed when the liquid temperature was 120 to 140°C. After holding at 190° C. for 30 minutes, the mixture was allowed to cool to room temperature and filtered. The obtained polyimide resin powder was washed with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, filtered, and then dried in a dryer at 180° C. for 10 hours to obtain 317 g of crystalline thermoplastic polyimide resin 1. (hereinafter also simply referred to as "polyimide resin 1") was obtained.
When the IR spectrum of polyimide resin 1 was measured, characteristic absorption of the imide ring was observed at ν(C═O) 1768, 1697 (cm ⁻¹ ). Logarithmic viscosity was 1.30 dL/g, Tm was 323°C, Tg was 184°C, Tc was 266°C, crystallization exotherm was 21.0 mJ/mg, semi-crystallization time was 20 seconds or less, and Mw was 55,000. there were.

Table 1 shows the composition and evaluation results of polyimide resin 1 in Production Example 1. The mol % of the tetracarboxylic acid component and the diamine component in Table 1 are values calculated from the amount of each component charged during the production of the polyimide resin.

Abbreviations in Table 1 are as follows.
・PMDA; pyromellitic dianhydride ・1,3-BAC; 1,3-bis(aminomethyl)cyclohexane ・OMDA; 1,8-octamethylenediamine

Example 1 (polyimide resin composition, production and evaluation of molded body)
After dry blending the polyimide resin 1 powder obtained in Production Example 1 and the amorphous resin (B1) ("ULTEM Resin 1000P" manufactured by SABIC, Tg: 217° C.) at the ratio shown in Table 2, Using a co-rotating twin-screw kneading extruder (“HK-25D” manufactured by Parker Corporation, screw diameter 25 mmΦ, L/D = 41), melt-kneading under the conditions of a barrel temperature of 370 ° C. and a screw rotation speed of 150 rpm. pushed out. After the strand extruded from the extruder was air-cooled, it was pelletized by a pelletizer ("Fan Cutter FC-Mini-4/N" manufactured by Hoshi Plastics Co., Ltd.). The obtained pellets were dried at 150° C. for 12 hours and then used for injection molding.
Using an injection molding machine (“Roboshot α-S30iA” manufactured by FANUC CORPORATION), injection molding is performed at a barrel temperature of 385°C, a mold temperature of 165°C, and a molding cycle of 60 seconds. Then, an injection-molded body for water absorption and CTE measurement was produced.
Various evaluations were performed by the methods described above using the obtained injection molded article. Table 2 shows the results.

Examples 2-4
Except for using the amorphous resin (B) of the type and amount shown in Table 2, and using the amorphous resin and the powder of the polyimide resin 1 obtained in Production Example 1 in the ratio shown in Table 2, An injection molded article was produced in the same manner as in Example 1, and various evaluations were performed. Table 2 shows the results.

Comparative example 1
The polyimide resin 1 powder obtained in Production Example 1 was melt-kneaded and extruded using Laboplastomill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a barrel temperature of 360° C. and a screw rotation speed of 150 rpm. After the strand extruded from the extruder was air-cooled, it was pelletized by a pelletizer ("Fan Cutter FC-Mini-4/N" manufactured by Hoshi Plastics Co., Ltd.). The obtained pellets were dried at 150° C. for 12 hours and then used for injection molding.
Using an injection molding machine ("ROBOSHOT α-S30iA" manufactured by FANUC CORPORATION), injection molding is performed with a barrel temperature of 350°C, a mold temperature of 200°C, and a molding cycle of 50 seconds. An injection molded body was prepared for water absorption and CTE measurements.
Various evaluations were performed by the methods described above using the obtained injection molded article. Table 2 shows the results.

Comparative example 2
Amorphous resin (B1) ("ULTEM Resin 1000P" manufactured by SABIC) was melt-kneaded and extruded using Laboplastomill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a barrel temperature of 360°C and a screw rotation speed of 150 rpm. After the strand extruded from the extruder was air-cooled, it was pelletized by a pelletizer ("Fan Cutter FC-Mini-4/N" manufactured by Hoshi Plastics Co., Ltd.). The obtained pellets were dried at 160° C. for 6 hours and then used for injection molding.
Using an injection molding machine ("ROBOSHOT α-S30iA" manufactured by FANUC CORPORATION), injection molding is performed with a barrel temperature of 350°C, a mold temperature of 180°C, and a molding cycle of 60 seconds. An injection molded body was prepared for water absorption and CTE measurements.
Various evaluations were performed by the methods described above using the obtained injection molded article. Table 2 shows the results.

Comparative example 3
Amorphous resin (B2) (“EXTEM Resin VH1003” manufactured by SABIC) was molded using an injection molding machine (“ROBOSHOT α-S30iA” manufactured by Fanuc Corporation) at a barrel temperature of 370 ° C. and a mold temperature of 160 ° C. , injection molding was performed with a molding cycle of 60 seconds, and a predetermined size was cut out to prepare an injection molded body for water absorption and CTE measurement.
Various evaluations were performed by the methods described above using the obtained injection molded article. Table 2 shows the results.

Comparative example 4
Amorphous resin (B3) ("SILTEM resin STM1700" manufactured by SABIC) was molded using an injection molding machine ("ROBOSHOT α-S30iA" manufactured by Fanuc Corporation) at a barrel temperature of 370°C and a mold temperature of 160°C. , injection molding was performed with a molding cycle of 60 seconds, and a predetermined size was cut out to prepare an injection molded body for water absorption and CTE measurement.
Various evaluations were performed by the methods described above using the obtained injection molded article. Table 2 shows the results.

Details of each component shown in Table 2 are as follows.
<Polyimide resin (A)>
(A1) Polyimide resin 1: crystalline thermoplastic polyimide resin 1 obtained in Production Example 1
<Amorphous Resin (B)>
(B1) 1000P: "ULTEM Resin 1000P" manufactured by SABIC, an amorphous resin composed of a repeating structural unit represented by the formula (B1), Tg: 185°C, MFR (temperature: 337°C, load: 6.6 kgf): 9 g /10 minutes (B2) VH1003: "EXTEM Resin VH1003" manufactured by SABIC, an amorphous resin composed of the repeating structural unit represented by the formula (B2), Tg: 243 ° C., MFR (temperature 367 ° C., load 6.6 kgf ): 15.5 g/10 minutes (B3) STM1700: "SILTEM resin STM1700" manufactured by SABIC, an amorphous resin consisting of a repeating structural unit represented by the formula (B3), MFR (temperature 295 ° C., load 6.6 kgf ): 7 g/10 minutes

As shown in Table 2, the molded articles made of the polyimide resin compositions of the present invention (Examples 1 to 4) have a lower linear thermal expansion coefficient and superior dimensional stability than the molded articles of Comparative Examples 1 to 4. In addition, it can be seen that the water absorption rate is lower than that of the molded body of the amorphous resin (B) alone.

Furthermore, using the pellets obtained in Example 2, the dispersion state of the polyimide resin (A) and the amorphous resin (B1) in the pellets was confirmed by the following method.
Using a microtome ("EM UC 7" manufactured by LEICA MICROSYSTEMS), the pellets obtained in Example 2 are perpendicular to the flow direction (MD) of the pellets as shown in FIG. like) cut. In FIG. 1, 1 is a pellet.
After staining this cut surface with ruthenium tetroxide for 30 minutes in the gas phase, a field emission scanning electron microscope (FE-SEM, "GeminiSEM500" manufactured by ZEISS) was used at an acceleration voltage of 1 kV and an observation magnification of 30,000. Observed under magnification (Fig. 2). In the observed image, dark-colored portions (islands) were determined to be composed of polyimide resin (A), which is difficult to be dyed with ruthenium tetroxide.
From FIG. 2, it can be seen that in the pellets obtained in Example 2, the polyimide resin (A) and the amorphous resin (B1) form a sea-island structure.

Claims

Including a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), the formula for the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) A polyimide resin containing a polyimide resin (A) having a repeating structural unit content ratio of 20 to 70 mol% of (1) and an amorphous resin (B) containing a repeating structural unit represented by the following formula (I) Composition.

(R 1 is a C 6-22 divalent group containing at least one alicyclic hydrocarbon structure. R 2 is a C 5-16 divalent chain aliphatic group. X 1 and X 2 are each independently a tetravalent group having 6 to 22 carbon atoms containing at least one aromatic ring.)

(R 4 is a divalent group having 6 to 22 carbon atoms containing at least one aromatic ring; R 5 is a divalent group represented by any of the following formulas (R-5a) to (R-5c) at least one of

(R 51 is an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkynyl group having 2 to 4 carbon atoms; m 51 is each independently an integer of 0 to 2; is an integer from 0 to 4. * indicates a bond.)

(each R 52 is independently an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkynyl group having 2 to 4 carbon atoms; each m 52 is independently an integer of 0 to 2; and p 52 are each independently an integer of 0 to 4. * indicates a bond.)

(each R 53 is independently an alkyl group having 1 to 4 carbon atoms or a phenyl group; each m 53 is independently an integer of 2 to 6; n is the average number of repeating units; * is a bond; show hand.)
The polyimide resin composition according to claim 1, wherein in formula (I), R 4 is a divalent group represented by any one of the following formulas (R-4a) to (R-4c).

(In the above formula, * indicates a bond.)
According to claim 1 or 2, wherein the absolute value of the linear thermal expansion coefficient measured in accordance with JIS K7197:2012 is 60 ppm/° C. or less for a 4 mm-thick molded body obtained by molding the polyimide resin composition. The polyimide resin composition described.
Mass ratio of the polyimide resin (A) to the total mass of the polyimide resin (A) and the amorphous resin (B) in the polyimide resin composition [(A) / {(A) + (B)} ] is 0.01 or more and 0.99 or less, the polyimide resin composition according to any one of claims 1 to 3.
A molded article containing the polyimide resin composition according to any one of claims 1 to 4.